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Publication Number: FHWA-HRT-11-030
Date: March 2011

Post-Earthquake Reconnaissance Report on Transportation Infrastructure: Impact of the February 27, 2010, Offshore Maule Earthquake in Chile

508 Captions

Figures

Figure 1. Map. Site locations visited by TIRT. This map shows the 32 transportation infrastructure sites that the Transportation Infrastructure Reconnaissance Team (TIRT) visited after the earthquake in the Maule region. The sites are shown as numbered dots and include highway bridges and port facilities from Santiago to Tubul, Chile.

Figure 2. Photo. TIRT team members and Chilean support personnel. This photo shows the team members of the Transportation Infrastructure Reconnaissance Team (TIRT) and supporting members from Chile. The 10 people are standing on a roadway and wearing reflective vests.

Figure 3. Map. Location of epicenter, seismic recording stations, and TIRT sites. This map shows the location of the earthquake epicenter relative to the 32 transportation sites visited by the Transportation Infrastructure Reconnaissance Team (TIRT). The epicenter is located approximately 208 mi (335 km) southwest of Santiago, 65 mi (105 km) northeast of Concepción, and 71 mi (115 km) west-southwest of Talca. There are white, yellow, and pink rectangular icons with accelerograms in the center. Stations with a white icon do not have accelerograms, stations with a yellow icon have accelerograms, and one station with a pink icon has digital ground motion records.

Figure 4. Map. Historic seismicity for Chile. This map shows a spatial relationship between previous earthquakes from 1900–1960 with a magnitude of 6.5 or greater, from 1964–present with a magnitude of 5.5 or greater, and the 2010 earthquake with a magnitude of 8.8. The map shows information about earthquake aftershock, depth, and rupture areas. The yellow star on the map indicates the 2010 offshore Maule earthquake epicenter, and its associated aftershocks are depicted as yellow circles. The points of initial rupture for the M8 or greater earthquakes are depicted as red circles with a black stroke. The estimated rupture zones of the 1922 M8.5 and 1960 M9.5 earthquakes are shown as white hashed areas.

Figure 5. Illustration. Conceptual diagram of a subduction zone earthquake. This three-part illustration shows the progression of a subduction zone earthquake where there is a horizontal movement of an overriding plate. The illustration on the left shows the plate boundary, with the crust of the subducting plate on the bottom, the crust of the overriding plate on the right, and the sea on the left. A tectonic plate subducts beneath an adjoining plate. The middle illustration shows the plates between earthquakes. The plates slide freely at great depth; however, at shallow depth, they stick together. This causes the overriding plate to bulge up. The illustration on the right shows the plates during an earthquake. The leading edge of the overriding plate, which is stuck between earthquakes, breaks free of the lower plate and springs toward the sea, causing a tsunami. The rest of the plate stretches and relaxes. This type of earthquake can cause many strong aftershocks as the plates adjust to the sudden changes in stresses.

Figure 6. Illustration. Offshore Maule earthquake aftershock distribution with depth. This figure illustrates the number and distribution of aftershocks resulting from the offshore Maule earthquake. A yellow star indicates the epicenter of the earthquake. The colors of the aftershock start at orange (0–22 mi (0–35 km) depth) followed by yellow (22–43 mi (35–70 km)), green (43–93 mi (70–150 km)), blue (93–190 mi (150–300 km)), magenta (190–310 mi (300–500 km)), and red (310–500 mi (500–800 km)).

Figure 7. Illustration. Accelerogram from Universidad de Chile, Depto. Ing. Civil (interior building). This graph shows ground motion data recorded at Universidad de Chile in Santiago.

Figure 8. Illustration. Response spectra from Universidad de Chile, Depto. Ing. Civil (interior building). This graph shows response spectra acceleration recorded at Universidad de Chile in Santiago based on the accelerogram in figure 7.

Figure 9. Illustration. Accelerogram from CRS Maipú RM. This graph shows ground motion data recorded at CRS Maipú RM near Santiago.

Figure 10. Illustration. Response spectra from CRS Maipú RM. This graph shows response spectra acceleration recorded at CRS Maipú RM based on the accelerogram in figure 9.

Figure 11. Illustration. Accelerogram from Hospital de Curicó. This graph shows ground motion data recorded at Hospital de Curicó.

Figure 12. Illustration. Response spectra from Hospital de Curicó. This graph shows response spectra acceleration recorded at Hospital de Curicó based on the accelerogram in figure 11.

Figure 13. Illustration. Accelerogram from San Pedro De La Paz, Colegio Concepción. This graph shows ground motion data recorded at San Pedro De La Paz, Colegio Concepción.

Figure 14. Illustration. Response spectra from San Pedro De La Paz, Colegio Concepción. This graph shows response spectra acceleration recorded at the San Pedro De La Paz, Colegio Concepción based on the accelerogram in figure 13.

Figure 15. Map. Locations of ground motion sensors and structures visited by TIRT—Santiago vicinity. This map shows the locations of ground motion sensors and transportation sites visited by the Transportation Infrastructure Reconnaissance Team (TIRT) in Santiago, Chile. Similar to figure 1, transportation sites are depicted as numbered white circles. The ground motion sensor locations are marked with yellow accelerogram icons. Six sites and five ground motion sensors are marked in this region.

Figure 16. Map. Locations of ground motion sensors and structures visited by TIRT—Santiago to Rancagua. This map shows the locations of ground motion sensors and transportation sites visited by the Transportation Infrastructure Reconnaissance Team (TIRT) from Santiago to Rancagua, Chile. Similar to figure 1, transportation sites are depicted as numbered white circles. The ground motion sensor locations are marked with yellow accelerogram icons. Seven sites and four ground motion sensors are marked in this region.

Figure 17. Map. Locations of ground motion sensors and structures visited by TIRT—Curicó, Talca, Iloca vicinity. This map shows the locations of ground motion sensors and transportation sites visited by the Transportation Infrastructure Reconnaissance Team (TIRT) in the vicinity of Curico, Talca, and Iloca, Chile. Similar to figure 1, transportation sites are depicted as numbered white circles. The ground motion sensor locations are marked with yellow accelerogram icons. Five sites and four ground motion sensors are marked in this region.

Figure 18. Map. Locations of ground motion sensors and transportation structures visited by TIRT—Concepción vicinity. This map shows the locations of ground motion sensors and transportation sites visited by the Transportation Infrastructure Reconnaissance Team (TIRT) in the vicinity of Concepción, Chile. Similar to figure 1, transportation sites are depicted as numbered white circles. The ground motion sensor locations are marked with yellow and pink accelerogram icons. Seven sites and four ground motion sensors are marked in this region.

Figure 19. Map. Locations of ground motion sensors and transportation structures visited by TIRT—Maule epicenter to Tubul vicinity. This map shows the locations of ground motion sensors and transportation sites visited by the Transportation Infrastructure Reconnaissance Team (TIRT) in the Tubul vicinity. Similar to figure 1, transportation sites are depicted as numbered white circles. There is a red circle at the top of the map indicating the epicenter of the offshore Maule earthquake. The ground motion sensor locations are marked with yellow and pink accelerogram icons. Ten sites and three ground motion sensors are marked in this region.

Figure 20. Illustration. Geologic cross section of Concepción. This figure shows a geologic cross section of Concepción depicting the bedrock, surface, and fault types near downtown Concepción. The faults depicted are Chepe Fault, La Poivora Fault, and Chacabuco Fault.

Figure 21. Map. Damaged sections in downtown Concepción. This figure shows a damage map of Concepción, Chile, due to the offshore Maule earthquake in February 2010. Five levels of damage are depicted in the map, with level 5 being the worst: level 5 (red), level 4 (orange), level 3 (yellow), level 2 (green), and level 1 (white). There is a red circle on the map indicating the location of the Colegio San Pedro monitoring station, which is between two heavily damaged areas.

Figure 22. Map. Seismic zone map for central Chile. This map shows the three seismic zones for central Chile which are numbered in vertical strips from east to west. These zones are determined by the value of the peak ground acceleration in still soil. They are separated by black dotted lines.

Figure 23. Photo. Damage to eastbound Independencia bridge. This photo shows the overall damage to the eastbound Independencia bridge. One of the bridge columns nearly collapsed due to the Maule earthquake and experienced a lateral offset greater than 1.6 ft (0.5 m). Temporary support beams were installed to help support the bridge.

Figure 24. Photo. Curtain wall at east abutment of eastbound Independencia bridge. This photo shows the curtain wall at the east abutment of the Independencia bridge. Heavy supports are present to help support the bridge temporarily.

Figure 25. Photo. Damage to steel stoppers on eastbound Independencia bridge. This photo shows damage to the steel stoppers on the Independencia bridge. A stopper has separated from the main bridge structure.

Figure 26. Illustration. Details of steel stoppers. This figure shows the details of steel stoppers. The stopper is anchored with two bolts along the traffic direction and is embedded 35 inches (900 mm) deep in a cap beam. Each stopper is in contact with the top face of the bottom flange of a girder and is intended to provide a restraint to vertical motion of the girder.

Figure 27. Photo. Typical flared wall pier of westbound Independencia bridge. This photo shows the typical flared wall pier for the westbound Independencia bridge. On the underside of the bridge, there are four support beams attached to the flared wall pier.

Figure 28. Photo. Displaced seismic bar on westbound Independencia bridge. This photo shows a displaced seismic bar on the westbound Independencia bridge. The seismic bar casing is broken.

Figure 29. Photo. Shear key damage at abutment of westbound Independencia bridge. This photo shows the shear key damage at the abutment of the westbound Independencia bridge.

Figure 30. Photo. Shear key damage at intermediate bents of westbound Independencia bridge. This photo shows damage to the westbound Independencia bridge. There were shear key failures in almost the entire structure.

Figure 31. Photo. Westbound Independencia bridge. This photo shows a close-up view of shear key damage on the westbound Independencia bridge.

Figure 32. Photo. Entrance ramp to westbound Independencia bridge. This photo shows the westbound Independencia bridge. The entrance ramp is supported on two hammerhead piers at the intermediate bents.

Figure 33. Photo. Shear key damage at entrance ramp abutment. This photo shows shear key damage at the abutment of the westbound Independencia bridge. There is a tape measure showing a gap approximately 1.5 inches (38 mm) wide between the abutment and the surrounding soil due to strong ground shaking.

Figure 34. Photo. Flared wall pier of exit ramp from westbound Independencia bridge. This photo shows the flared wall pier of the exit ramp of the westbound Independencia bridge. There is minor damage due to pounding in the corner of the beam recess.

Figure 35. Photo. Close-up of damage to exit ramp from westbound Independencia bridge. This photo shows a close-up view of the flared wall pier of the exit ramp of the westbound Independencia bridge. There is damage on the left side of the wall pier due to the earthquake.

Figure 36. Photo. Curtain wall shear failure at abutment of Chada bridge. This photo shows damage to the Chada bridge overpass. The wall shear at the abutment is cracked, and a large piece of concrete is hanging off of the bridge.

Figure 37. Photo. Bottom flange damage to Chada bridge. This photo shows bottom flange damage to the Chada bridge overpass. There are four cross beams underneath the bridge, and the beam on the left has a large crack in the middle.

Figure 38. Photo. Curtain wall damage at bent of Chada bridge. This photo shows damage to the curtain wall at the intermediate bent of the Chada bridge overpass. There is a large horizontal crack along the wall near the bent.

Figure 39. Photo. Soil separation from column of Chada bridge. This photo shows soil separation around a column of the Chada bridge. There is a large gap along the left side of the column due to strong shaking.

Figure 40. Illustration. Plan view of superstructure rotation of Chada bridge. This illustration shows the rotation of the Chada bridge due to the earthquake. There is a horizontal rectangle outlined in a black dashed line to indicate the original placement of the bridge. There are three circles aligned vertically in the center of the rectangle, representing the location of three columns. The bridge rotated counterclockwise with a permanent displacement of 25 inches (64 cm) on one end (right) and 30 inches (78 cm) on the other (left).

Figure 41. Photo. Las Mercedes bridge and girder unseating at abutments. This photo shows the two-span Las Mercedes bridge overpass in the east-west direction. It is a concrete girder structure that experienced damage to the left abutment. There is a large crack separating the bridge from the abutment.

Figure 42. Photo. Llacolen bridge looking south-southwest. This photo shows the Llacolen bridge over the Biobío River in Concepción in the northeast-southwest direction. It is a multispan, simply supported concrete girder bridge. There is an arrow pointing to the left to indicate the east abutment and an arrow pointing to the right to indicate the west abutment. In front of the bridge, there is a concrete block sidewalk lined with grass and trees.

Figure 43. Photo. Unseated simply supported span in eastern approach to Llacolen bridge. This photo shows a simply supported span in the eastern approach to the Llacolen bridge. It dropped from its seat at the river end of the span. A temporary Bailey bridge was erected to give traffic access to the main crossing.

Figure 44. Photo. Abutment at unseated end of span in eastern approach to Llacolen bridge. This photo shows the abutment at the unseated end of the span of the Llacolen bridge. The end bent remained intact except for concrete spalling underneath the cap beam. There are also deformed seismic bars, which are circled.

Figure 45. Photo. Concrete spalling beneath cap beam of eastern approach to Llacolen bridge. This photo shows concrete spalling beneath the capbeam of the Llacolen bridge. Cracks are circled underneath the bridge between two columns. Above the cracks, seismic bars are circled.

Figure 46. Photo. Flexural cracks at the level of rip rap on eastern approach to Llacolen bridge. This photo shows flexural cracks at the level of rip rap of the Llacolen bridge. The cracks appear on the river side of the columns, where tension developed as the superstructure held the columns against the lateral movement imposed on the foundation.

Figure 47. Photo. Close-up view of cracks at the level of rip rap on eastern approach to Llacolen bridge. This photo shows a close-up of a major horizontal crack. A penny was placed in the crack to show its size. The crack is slightly wider than the thickness of a penny.

Figure 48. Photo. Ground settlement and lateral movement of eastern approach to Llacolen bridge. This photo shows ground settlement and lateral movement underneath the Llacolen bridge. The nearby ground settled up to 1.3 ft (0.4 m). The earthquake caused a separation of 0.82 ft (0.25 m) between the two columns in the photo and the surrounding ground.

Figure 49. Photo. Exterior face of westbound ramp to Llacolen bridge at the river end. This photo shows the exterior face of the westbound ramp to the Llacolen bridge. There is a large separation at the river end of the last span.

Figure 50. Photo. Interior face of westbound ramp to Llacolen bridge at the river end. This photo shows the interior face of the ramp at the river end. There is a separation of the bridge from the interior face.

Figure 51. Photo. Bent of westbound ramp to Llacolen bridge. This photo shows a bent of the ramp to the Llacolen bridge. There is an expansion joint in the bridge deck.

Figure 52. Photo. Seismic bar condition on westbound ramp to Llacolen bridge. This photo shows a seismic bar in the ramp to the Llacolen bridge. The circled bar is rusty due to the earthquake.

Figure 53. Photo. Neoprene pad degradation on westbound ramp to Llacolen bridge. This photo shows a neoprene pad in the ramp to the Llacolén bridge. The circled pad has degraded.

Figure 54. Photo. Columns with soil marks indicating ground settlement at west end of Llacolen bridge. This photo shows the underside of the Llacolen bridge. There are five columns with soil marks on the bottom, indicating ground settlement.

Figure 55. Photo. Sand boils near columns at west end of Llacolen bridge. This photo shows a close-up of three of the columns of the Llacolen bridge. The soil marks are visible on the bottom ends of the columns, and sand boils are in front of the columns.

Figure 56. Photo. Spalling in deck slab at west end of Llacolen bridge. This photo shows damage at the west end of the Llacolen bridge due to pounding. Spalling can be seen in the deck slab of the bridge.

Figure 57. Photo. Horizontal crack in web of end girders at west end of Llacolen bridge. This photo shows a horizontal crack in the web of end girders beneath the west end of the Llacolen bridge.

Figure 58. Photo. Spalling of shear key at southwest abutment of Llacolen bridge. This photo shows spalling of the shear key at the southwest abutment of the Llacolén bridge. Damage occurred when the girders engaged the concrete keys on the west abutment.

Figure 59. Photo. Approaches to Juan Pablo II bridge. This photo shows the northern approach and its relation to the Juan Pablo II bridge. The approach structure is a two-span bridge. The main Juan Pablo II bridge crosses the Biobío River in Concepción. The bridge has a guard rail and is surrounded by grass.

Figure 60. Photo. Southwest view of northern approach to Juan Pablo II bridge, facing Biobío River. This photo shows damage in the northern approach to the Juan Pablo II bridge in the direction of the Biobío River. The bridge supports two-way traffic with two lanes in each direction. There are large cracks in the roadway across all four lanes.

Figure 61. Photo. Northeast view of northern approach to Juan Pablo II bridge, facing away from Biobío River. This photo shows the Juan Pablo II bridge facing away from the Biobío River. There is significant settlement, creating a clear depression in the roadway.

Figure 62. Photo. Intermediate bent of northern approach to Juan Pablo II bridge. This photo shows damage to the intermediate bent of the Juan Pablo II bridge.

Figure 63. Photo. Column settlement under approach to Juan Pablo II bridge (cracks on far side). This photo shows column settlement under the Juan Pablo II bridge. The column settled with the surrounding soils.

Figure 64. Photo. Reduced column height due to shear failure under approach to Juan Pablo II bridge. This photo shows reduced column height to a column of the Juan Pablo II bridge. The reduction was due to shear failure. The column is severely cracked and crumbling.

Figure 65. Photo. Soil surface on far side of undamaged column under approach to Juan Pablo II bridge. This photo shows a worker marking where the soil used to be on an undamaged column of the Juan Pablo II bridge.

Figure 66. Photo. Cracks on far side of undamaged column under approach to Juan Pablo II bridge. This photo shows cracks on the far side of an undamaged column of the Juan Pablo II bridge.

Figure 67. Photo. Differential settlement underneath first span over water at northern end of Juan Pablo II bridge. This photo shows the underside of the Juan Pablo II bridge. The spans appear to have experienced uneven support settlement, which tilted the columns and rotated the bridge deck about the centerline of the bridge. Cracks appear on the columns.

Figure 68. Photo. Shear failure in upstream column at northern end of Juan Pablo II bridge. This photo shows shear failure in the upstream column of the Juan Pablo II bridge. The column is completely cracked and broken.

Figure 69. Photo. Front face of failure plane at northern end of Juan Pablo II bridge. This photo shows a worker measuring the front face of a failure plane of the Juan Pablo II bridge. There are significant cracks and damage to the front face.

Figure 70. Photo. Back face of failure plane at northern end of Juan Pablo II bridge. This photo shows a worker measuring the back face of a failure plane of the Juan Pablo II bridge. There is a very large crack in and damage to the back face.

Figure 71. Photo. Shear failure in downstream column at northern end of Juan Pablo II bridge. This photo shows shear failure in the downstream column of the Juan Pablo II bridge. There is severe damage to the column. The concrete appears crumbled and cracked.

Figure 72. Map. Satellite image of Ramadillas bridges. This map shows a satellite view of the east and west Ramadillas bridges. The bridges cross over the Piteateo River from the south to the north. The south and north abutments are labeled in the figure. Ramadillas is located north of the bridge.

Figure 73. Photo. Side view of east Ramadillas bridge. This photo shows a side view of the east Ramadillas bridge crossing the Piteateo River. There is an arrow pointing forward to indicate the north abutment and an arrow pointing backward to indicate the south abutment. An additional arrow is pointing to a wall-type pier supporting the bridge.

Figure 74. Photo. Wall-type pier beneath east Ramadillas bridge. This photo shows the underside of the east Ramadillas bridge. Arrows point to a reinforced concrete diaphragm, a shear key, and a wall-type pier.

Figure 75. Photo. Deck misalignment under east Ramadillas bridge. This figure provides a close-up view of the east Ramadillas bridge. The piers underneath the bridge settled, causing vertical misalignment of the deck. There is a visible dip in the bridge. There is an arrow pointing down to indicate settlement.

Figure 76. Photo. Sand boils close to pier under east Ramadillas bridge. This photo shows a wall-type pier underneath the east Ramadillas bridge. Arrows point to sand boils near the pier.

Figure 77. Photo. Overview of west Ramadillas bridge. This photo shows a view of the west Ramadillas bridge. A wall-type pier, steel girders, and X-bracing are visible.

Figure 78. Photo. Abutment damage beneath west Ramadillas bridge. This photo shows a close-up of an abutment of the west Ramadillas bridge. Steel girders and X-bracing are visible. Arrows point to concrete spalling on the abutment.

Figure 79. Photo. Pier rotation in collapsed span of west Ramadillas bridge. This photo shows a horizontal view of the west Ramadillas bridge. One of the columns rotated during the earthquake, causing the concrete slab to collapse.

Figure 80. Photo. Sand boils near collapsed span in west Ramadillas bridge. This photo shows sand boils around the collapsed span of the west Ramadillas bridge.

Figure 81. Photo. Settlement at south abutment under east Ramadillas bridge. This photo shows soil settlement under the east Ramadillas bridge. A black line on the wall-type pier indicates the soil surface level before the earthquake. Cracks in the soil show the extent of the soil sliding.

Figure 82. Photo. Sliding at south abutment under west Ramadillas bridge. This photo shows soil sliding under the west Ramadillas bridge. There are cracks in the soil in front of a wall-type pier, indicating soil sliding.

Figure 83. Photo. Block flow toward river due to liquefaction on south bank of Ramadillas bridges. This pair of photos shows soil sliding under the two Ramadillas bridges. The left photo is under the east bridge. The right photo is under the west bridge. There are a large crevices in the land due to soil sliding.

Figure 84. Photo. Northeast end of Miraflores bridge. This photo shows a side view of the northeast end of the Miraflores bridge. Each three-span prestressed precast girder has five discontinuous girders and a continuous deck slab. There is a collapsed span at the northeast abutment.

Figure 85. Photo. Southwest end of Miraflores bridge. This photo shows a side view of the southwest end of the Miraflores bridge.

Figure 86. Photo. Top view of Miraflores bridge from far side. This photo shows a top view from the far side of the Miraflores bridge. There is a collapsed span in the bridge, creating a large crack along the entire bridge. There are automobiles on the bridge on the falling span of the bridge.

Figure 87. Photo. Bottom view of Miraflores bridge from near side. This photo shows a bottom view from the near side of the Miraflores bridge. There is a five-column support under the bridge.

Figure 88. Photo. Collapsed span of Miraflores bridge. This photo shows the underside of a collapsed span of the Miraflores bridge. As a result of the earthquake, the span is not connected to the abutment.

Figure 89. Photo. Miraflores bridge after removal of superstructure. This photo shows the Miraflores bridge after the removal of the bridge superstructure. Two four-column supports and the northeast abutment remain in place. Damage to the abutment curtain walls is circled.

Figure 90. Photo. Acute corner of southwest abutment of Miraflores bridge. This photo shows the acute corner of the southwest abutment of the Miraflores bridge. Damage on the curtain wall is visible, as is a steel stopper on the concrete.

Figure 91. Photo. Obtuse corner of southwest abutment of Miraflores bridge. This photo shows the obtuse corner of the Miraflores bridge without any visible damage to the curtain wall. An arrow points to a concrete pedestal.

Figure 92. Photo. Collapsed northeast-bound Lo Echevers bridge. This photo shows the collapse of the northeast-bound Lo Echevers bridge. The bridge is detached from its support, and automobiles are flipped over because of the collapse.

Figure 93. Photo. Three unseated spans of northeast-bound Lo Echevers bridge. This photo shows three unseated spans of the northeast-bound Lo Echevers bridge. The bridge superstructure is detached from the supports and laying on the ground.

Figure 94. Photo. Failure of a steel stopper on Lo Echevers bridge. This photo shows the failure of a steel stopper of the Lo Echevers bridge. Some of the anchor bolts fractured.

Figure 95. Photo. Displaced elastomeric bearing on Lo Echevers bridge. This photo shows a displaced elastomeric bearing of the Lo Echevers bridge. The bearings show significant lateral bulging and may have been overstressed under gravity loads.

Figure 96. Illustration. Intermediate bent details for Romero bridge. This illustration shows the intermediate bent details for the Romero bridge. The bridge has five girders but no diaphragms. Two seismic bars are provided between each pair of adjacent girders. The intermediate bent has four columns that are supported by four drilled shafts with a pile cap between the columns and their drilled shaft foundation. Each abutment rests on four drilled shafts.

Figure 97. Photo. Collapse of the Romero bridge. This photo shows damage to the Romero bridge. There are views of damage to both the far and near sides of the bridge. Both spans were unseated at their abutments, and lateral shear failures occurred in the webs of both the exterior girders over the bent due to excessive transverse loads. There is a break in the concrete in the middle of the bridge. As a result, the left side of the bridge slopes upward, and the right side of the bridge slopes downward.

Figure 98. Photo. Seismic bars at west abutment of Romero bridge. This photo shows damage to the seismic bars at the west abutment of the Romero bridge. Arrows point to the damaged curtain wall, the seismic bars, the drilled shaft, and the undamaged curtain wall.

Figure 99. Photo. Seismic bars at east abutment of Romero bridge. This photo shows the seismic bars at the east abutment of the Romero bridge. Arrows point to the intact shear key, the east abutment, the damaged curtain wall, the seismic bars, the intact curtain wall, and the shear key that was knocked off.

Figure 100. Photo. Pounding at west abutment of Romero bridge. This photo shows damage to the back wall and wing wall of the Romero bridge, resulting from the girder impact on the west abutment. An arrow points to the pounding marks.

Figure 101. Photo. Back wall and wing wall damage at west abutment of Romero bridge. This photo shows wing wall damage at the west abutment of the Romero bridge. Arrows point to cracks and damage on the wing wall.

Figure 102. Photo. Three bridges (one demolished) at Route 5 overcrossing at Hospital. This photo shows an overview of three bridges: one steel plate girder bridge and two prestressed precast concrete girder bridges at the Hospital overcrossing. The southbound concrete girder bridge collapsed. It appears that the top of columns below the steel girders yielded and formed a plastic hinge. Workers are standing below the bridge assessing the damage.

Figure 103. Photo. Collapse of Route 5 overcrossing at Hospital. This photo shows the collapse of the Hospital overcrossing. The bridge runs from northwest to southeast. An arrow points to the south abutment at the top of the photo. The south span partially fell from the south abutment, while the north span was completely unseated. The superstructure rotated clockwise away from the acute corner.

Figure 104. Photo. Damage at north abutment of Route 5 overcrossing at Hospital. This photo shows damage at the north abutment of the Hospital overcrossing. The bridge superstructure was removed. Circle indicate pounding on the back wall and where an acute corner curtain wall was knocked off.

Figure 105. Photo. Damage at south abutment of Route 5 overcrossing at Hospital. This photo shows damage at the south abutment of the Hospital overcrossing. The bridge superstructure was removed. Circles indicate the area where the obtuse corner curtain wall is intact and where the acute corner curtain wall was knocked off. Close-ups of these two areas are provided.

Figure 106. Photo. Overview of Quilicura railway overcrossing. This photo shows damage to the Quilicura railway overcrossing. It is a three-span steel bridge with five simply supported girders, a continuous deck slab, and seat-type abutments.

Figure 107. Photo. Cross frames on Quilicura railway overcrossing. This photo shows the cross frames and steel diaphragm on the underside of the Quilicura railway overcrossing.

Figure 108. Photo. Stiffeners on Quilicura railway overcrossing. This photo shows the stiffeners and bent columns from the left side of the Quilicura railway overcrossing.

Figure 109. Photo. East abutment of Quilicura railway overcrossing. This photo shows the collapse of the east abutment of the Quilicura railway overcrossing. Arrows point to the bridge acute corner and the curtain wall damage. The end span on the east side is unseated at the abutment.

Figure 110. Photo. West abutment of Quilicura railway overcrossing. This photo shows the the west abutment of the Quilicura railway overcrossing. Labels indicate the acute corner and the curtain wall damage. The span on the west side is laterally displaced and almost unseated.

Figure 111. Photo. West span of Quilicura railway overcrossing lowered onto sandbank. This photo shows the underside of the west span of the Quilicura bridge, which was lowered onto a sandbank following the earthquake.

Figure 112. Photo. Damage to anchor bolts on Quilicura railway overcrossing. This photo shows anchor bolt failure on a steel stopper of the Quilicura railway overcrossing.

Figure 113. Photo. Damage to cross frame on Quilicura railway overcrossing. This photo shows the underside of the Quilicura railway overcrossing, where cross frame buckling can be seen. Lateral forces on the superstructure damaged the girder anchor bolts and buckled some of the cross frames.

Figure 114. Photo. Unseating at southern ends of each span of Tubul bridge. This photo shows unseating at the southern ends of all spans of the Tubul bridge. They are all are disconnected and slope up at various angles.

Figure 115. Photo. Punching of Tubul bridge deck into back wall. This photo shows punching of the bridge deck into the back wall of the north abutment of the Tubul bridge. A large crack can be seen between the wall and the bridge deck.

Figure 116. Photo. Buckling of pavement at north abutment of Tubul bridge. This photo shows buckling of the pavement at the north abutment of the Tubul bridge. The road pavement is distorted and cracked.

Figure 117. Photo. Span 6 of Tubul bridge, unseated at north end during an aftershock. This series of photos shows span 6 of the Tubul bridge. The left photo shows the north end. The span is circled. The center photo shows span 6 in relation to the other unseated spans of the bridge. The span is again circled. The right photo shows watermarks on the underside of the Tubul bridge. Labels indicate areas of high and average watermarks. Another label indicates the top of the footing.

Figure 118. Photo. Bottom flange buckling and concrete spalling on Tubul bridge. This photo shows buckling of the bottom flange and concrete spalling of the Tubul bridge.

Figure 119. Photo. Shear crack in Tubul bridge. This photo shows a shear crack in a column underneath the Tubul bridge.

Figure 120. Photo. Tilting wall pier on Tubul bridge. This photo shows tilting of a wall pier of the Tubul bridge. A bridge support is tilting to the right, and the superstructure is out of place.

Figure 121. Photo. Spalling due to shear action and vertical crack in Tubul bridge. This photo shows spalling due to shear action and a vertical crack on the Tubul bridge.

Figure 122. Photo. Crack in footing of Tubul bridge. This photo shows a crack in the footing of the Tubul bridge.

Figure 123. Photo. View of Cardenal Raúl Silva Henríquez bridge looking south. This photo shows a side view of the Cardenal Raúl Silva Henríquez bridge. The bridge crosses a river on three-column bents. An arrow pointing to the left indicates northeast, and an arrow pointing to the right indicates southwest.

Figure 124. Photo. Elastomeric pad and stopper over bent on Cardenal Raúl Silva Henríquez bridge. This photo shows an elastomeric pad and stopper over a bent of the Cardenal Raúl Silva Henríquez bridge. The steel stoppers restrained transverse and vertical movements during the earthquake.

Figure 125. Photo. Girder offset and cross frame buckling on Cardenal Raúl Silva Henríquez bridge. This photo shows buckling of the end diaphragm of the Cardenal Raúl Silva Henríquez bridge. The northeast portion of the bridge moved from west to east in the transverse direction.

Figure 126. Photo. Cross frame buckling on Cardenal Raúl Silva Henríquez bridge. This photo shows buckling of the end diaphragm of the Cardenal Raúl Silva Henríquez bridge.

Figure 127. Photo. Girder damage at northeast abutment of Cardenal Raúl Silva Henríquez bridge. This photo shows girder damage at the north abutment of the Cardenal Raúl Silva Henríquez bridge. The webs and bottom flanges were fractured in all three steel girders, and both bearing stiffener and web buckling occurred.

Figure 128. Photo. Temporary repair at northeast abutment of Cardenal Raúl Silva Henríquez bridge. This photo shows temporary repair at the north east abutment of the Cardenal Raúl Silva Henríquez bridge. A temporary cross frame was installed. Two vertical supports are shown on each side, as are a floor beam welded to a girder and X-bracing.

Figure 129. Photo. Spans and pile bents of southwest portion of Cardenal Raúl Silva Henríquez bridge. This photo shows a side view of the southern spans and pile bents of the Cardenal Raúl Silva Henríquez bridge. Nine spans of the southwest portion of the bridge are supported on tall steel pile bents over a body of water.

Figure 130. Photo. Erosion of alluvial material around bent legs of Cardenal Raúl Silva Henríquez bridge. This photo shows erosion of alluvial material around three bent legs of the Cardenal Raúl Silva Henríquez bridge. Waves due to the earthquake eroded river sands and gravel from around the piles.

Figure 131. Photo. Debris-impact hole in bent leg of Cardenal Raúl Silva Henríquez bridge. This photo shows a hole punctured in the wall of one of the legs of one of the bents due to wave-borne debris.

Figure 132. Photo. Fillet weld fractures at the girder-to-abutment connection on the Cardenal Raúl Silva Henríquez bridge. This photo shows damage at the southwest abutment of the Cardenal Raúl Silva Henríquez bridge. The weld fractures showed damage at the girder-to-abutment connection.

Figure 133. Photo. Close-up of girder end on Cardenal Raúl Silva Henríquez bridge. This photo shows a close-up view at the girder end at the southwest abutment of the Cardenal Raúl Silva Henríquez bridge. The girder is surrounded and covered by gravel.

Figure 134. Photo. Close-up of transverse stiffeners on Cardenal Raúl Silva Henríquez bridge. This photo shows a close-up view of the transverse stiffeners of the Cardenal Raúl Silva Henríquez bridge. The stiffeners are covered in gravel.

Figure 135. Photo. Collapsed spans in Biobío River bridge. This photo shows collapsed spans in the Biobío River bridge, which is oriented east-west. The bridge superstructure consists of multiple simply supported spans with four steel girders and a concrete deck. Intermediate and end X-braced cross frames are provided in each span. In the middle of the bridge, the collapsed spans are visible.

Figure 136. Photo. Unseated spans in Biobío River bridge. This photo shows a close-up view of the unseated spans of the Biobío River bridge. The spans have separated from the bridge and collapsed.

Figure 137. Photo. Lateral spreading near east end of Biobío River bridge. This photo shows lateral spreading due to liquefaction near the north end of the Biobío River bridge approaches.

Figure 138. Photo. Collapsed spans and piers of Biobío River bridge. This photo shows a panoramic view of collapsed spans and piers of the Biobío River bridge. The bridge is over a body of water with mountains in the background. The bridge runs horizontally in the photo, and several spans and piers have collapsed in the water.

Figure 139. Photo. Cracks in pile caps of Biobío River bridge. This set of photos shows a close-up view of cracks in pile caps of the Biobío River bridge.

Figure 140. Photo. Satellite image of the Pichibudis bridge. This photo shows a satellite image of the Pichibudis bridge. The bridge crosses over a body of water with grass and trees on both banks. Labels indicate the northeast and southwest abutments. An arrow pointing upstream to the left indicates the sea. An arrow pointing southwest shows the direction toward Iloca.

Figure 141. Photo. Cross frames in Pichibudis bridge. This photo shows details of the cross frames of the girders of the Pichibudis bridge.

Figure 142. Photo. Web stiffeners in Pichibudis bridge. This photo shows a side view of the web stiffeners of the Pichibudis bridge.

Figure 143. Photo. Offset in girder top flange of south abutment of Pichibudis bridge. This photo shows lateral offset at the south abutment of the Pichibudis bridge. The deck slab suffered a permanent lateral displacement of about 7 inches (18 cm) at the south abutment. The seaward girder rotated about the bottom flange and suffered flexural and torsional deformations about the weak axis of the section.

Figure 144. Photo. Offset in handrail on south abutment of Pichibudis bridge. This photo shows offset in the handrail of the Pichibudis bridge. The deck slab suffered a permanent lateral displacement of about 7 inches (18 cm) at the south abutment. The seaward girder rotated about the bottom flange and suffered flexural and torsional deformations about the weak axis of the section.

Figure 145. Photo. X-braces damage in south abutment of Pichibudis bridge. This photo shows X-brace damage at the south abutment of the Pichibudis bridge. Compression buckling and tension rupture are visible.

Figure 146. Photo. Diaphragm crushing in south abutment of Pichibudis bridge. This photo shows diaphragm crushing and girder damage at the south abutment of the Pichibudis bridge.

Figure 147. Photo. Damage on south abutment due to corrosion in Pichibudis bridge. This pair of photos shows corrosion damage in the Pichibudis bridge. The left photo shows girder corrosion and the right photo shows a fractured vertical restrainer on the south abutment.

Figure 148. Photo. Satellite image of El Bar bridge. This photo shows a satellite image of the El Bar bridge, which is oriented north-south. Labels indicate the north and south abutments of the bridge. An old railway is right of the bridge, surrounded by trees and grass.

Figure 149. Photo. Side view of El Bar bridge. This photo shows a close-up side view of the El Bar bridge over a body of water. A new girder, which was recently added to the bridge, is labeled, as is a midspan structure.

Figure 150. Photo. Retrofit girder connections on El Bar bridge. This photo shows the underside of the El Bar bridge. An old girder, new girder, and a girder connector are marked.

Figure 151. Photo. Retrofit deck connections on El Bar bridge. This photo shows deck connectors and bearing stiffeners on the underside of the El Bar bridge.

Figure 152. Photo. Lateral deformation at south abutment of El Bar bridge. This photo shows damage at the south abutment of the El Bar bridge. Workers are measuring a lateral permanent deformation of 9.8 inches (25 cm).

Figure 153. Photo. Damage at south abutment of El Bar bridge. This photo shows the underside of the El Bar bridge. There is damage to the concrete back wall as well to girders, which were dislodged from their neoprene pads.

Figure 154. Photo. Damage to rebar X-brace system on north abutment of El Bar bridge. This photo shows damage to the underside of the north abutment of the El Bar bridge. Workers are seen observing damage to the rebar X-brace system.

Figure 155. Photo. Damage to north abutment back wall of El Bar bridge. This photo shows damage to the north abutment back wall of the El Bar bridge. There are cracks and crumbled concrete on the back wall of the abutment.

Figure 156. Photo. Satellite image of Itata River bridge. This photo shows a satellite image of a bridge that runs east-west over the Itata River. There are labels on the photo that indicate the west and east abutments. Below the west abutment is an arrow pointing south to Coelemu.

Figure 157. Photo. Side view and superstructure details for Itata River bridge. This pair of photos shows the Itata River bridge. The left photo is a side view. An arrow pointing left indicates the west abutment and an arrow pointing right indicates the east abutment. One of the wall-type piers is marked. The right photo shows the underside of the bridge. The wall-type pier, reinforced concrete diaphragm, and cross frames are labeled.

Figure 158. Photo. Girder supports at each pier of Itata River bridge. This pair of photos shows girder supports. The left photo shows a side view of girder supports at the piers of the Itata River bridge. Each girder sits on a reinforced concrete bracket at the top of each pier. The right photo shows an underside view of the girder supports. Arrows point to brackets on the pier.

Figure 159. Photo. Damage to girder supports of Itata River bridge. This pair of photos shows two views of damage to the girder supports of the Itata River bridge. In the left photo, shear cracks and bar buckling are visible. The right photo photo shows an underside view in which concrete spalling is visible.

Figure 160. Photo. Damaged Route 5 pedestrian bridge. This photo shows damage to a Route 5 pedestrian bridge. The two bridge spans fell from their supports during the earthquake and were moved to the two sides of the highway.

Figure 161. Photo. Steel girder on neoprene pad at abutment of Route 5 pedestrian bridge. This photo shows a steel girder on a neoprene pad at the abutment of a Route 5 pedestrian bridge.

Figure 162. Photo. End cross frame near collapsed span of Route 5 pedestrian bridge. This photo shows an end cross frame below one of the collapsed spans of the Route 5 pedestrian bridge.

Figure 163. Photo. Anchor bolt failure (shear and pull out) on Route 5 pedestrian bridge. This photo shows a broken anchor bolt and cross frame from the Route 5 pedestrian bridge.

Figure 164. Illustration. Highway bridges crossing Claro River before earthquake. This illustration shows parallel arch bridges across over the Claro River just south of Curicó. The closer of the two bridges has six piers. The northeast abutment is on the left, and the southwest abutment is on the right.

Figure 165. Photo. Collapse of masonry arch bridge at Claro River. This photo shows earthquake damage to the unreinforced masonry arch bridge, which crosses the Claro River. Piers 1–6 are labeled, as is the southwest abutment on the right. In the distance, a reinforced concrete arch bridge and a steel arch railway bridge are visible. Several of the piers of the masonry arch bridge collapsed.

Figure 166. Photo. Close-up view of collapsed bridge at Claro River. This pair of photos shows the damage to the Claro River bridge. The left photo shows a view of where the superstructure collapsed into the river below. The right photo shows a side view of the bridge, and the crumbled superstructure can be seen below the remaining pier.

Figure 167. Photo. Deck slab and crown of arch on Claro River bridge. This photo shows the brick arch, which is 4 ft tall, and the stone fillers of the Claro River bridge. Various components of the bridge have collapsed, and workers are seen in the distance assessing the damage.

Figure 168. Photo. Pier of Claro River bridge. This series of photos provides several close-up views of one of the piers of the collapsed Claro River bridge. Significant cracking and spalling can be seen in the remaining structure.

Figure 169. Photo. Foundation of Claro River bridge. This photo shows a close-up view of the foundation of the Claro River bridge. The foundation is mostly made of stone blocks that seemed to have experienced little or no damage during the earthquake.

Figure 170. Illustration. Scenario for the progressive collapse of Claro River bridge. This series of drawings depicts the collapse of the Claro River bridge. The first illustration shows the pre-earthquake condition. The ground surface, rock surface, water level, and structure boundary are labeled. The bridge has seven arches, which are intact. The next illustration shows step 1 of the collapse after the earthquake. The bending moment distribution along the axis of the arch bridge was uneven under the earthquake load, and the maximum moment most likely occurred in the end spans. As a result, each end arch was subjected to cracking. The third illustration shows step 2 of the collapse. There was a loss of thrust for the adjacent spans, which caused significant force redistribution, resulting in cracking and collapse of the spans. The fourth illustration shows step 3 of the collapse. Due to cracking and collapse of spans in step 2, additional collapse resulted. The final illustration shows step 4 of the collapse. The center span experienced force redistribution due to the collapse of its adjacent spans. However, the change in horizontal thrust for the center span was likely smaller than that in the other intermediate spans. In addition, the earthquake excitation was likely over by that time. Therefore, the arch collapsed mainly due to its own weight, but the two piers supporting the center span remained intact.

Figure 171. Photo. North end of Chepe railroad bridge over roadway. This photo shows the north end of the Chepe railroad bridge, which runs over a roadway. The bridge is oriented in the northeast-southwest direction and has two continuous through-truss spans at the north end.

Figure 172. Photo. River spans of Chepe railroad bridge. This photo shows the river spans of the Chepe railroad bridge. Bents with six steel piles are visible.

Figure 173. Photo. South end of Chepe railroad bridge. This photo shows the south end of the Chepe railroad bridge over the Biobío River.

Figure 174. Photo. Bottom view and cross section on the north end of Chepe railroad bridge. This photo shows a bottom view of the north end of the Chepe railroad bridge over the Biobío river. Concrete-filled steel tubes are visible.

Figure 175. Photo. Section on the south end of Chepe railroad bridge. This photo shows a close-up view of a section on the south end of the Chepe railroad bridge over the Biobío River. A bent with six steel piles is visible.

Figure 176. Illustration. Settlement and lateral movement of wall and bent due to ground spreading under Chepe railroad bridge. This illustration shows the settlement and lateral movement of a wall and bent due to ground spreading under the Chepe railroad bridge. At the northeast end, the bridge spans over Route O-60, which runs under the spans in a trench between two retaining walls.

Figure 177. Photo. Settlement and tilting of bent on Chepe railroad bridge. This photo shows an underside view of the Chepe railroad bridge. A bent tilted 26 inches (660 mm) toward the river, shifting the centerline of the bent. There was also ground settlement of 51 inches (1,300 mm).

Figure 178. Photo. Settlement behind retaining wall on Chepe railroad bridge. This photo shows relative wall settlement of approximately 12 inches (300 mm) and lateral movement behind a retaining wall.

Figure 179. Photo. Ruptured cross bracing at south end of Chepe railroad bridge. This photo shows ruptured cross bracing at the south end of the Chepe Railroad bridge.

Figure 180. Photo. Fractured steel piles at south end of Chepe railroad bridge. This photo shows fractured steel piles at the south end of the Chepe Railroad bridge.

Figure 181. Photo. Three parallel bridges crossing the Maipú River south of Santiago. This pair of photos show three bridges that cross the Maipú River: a railway bridge, a highway bridge, and a local access road bridge.

Figure 182. Photo. Crushing of haunches at pier 3 of Maipú River bridge. This photo shows damage to pier 3 of the Maipú River bridge. The haunches of three girders were severely crushed.

Figure 183. Photo. Shear cracks at span 1 of Maipú River bridge. This photo shows span 1 of the Maipú River bridge. Two temporary frames were installed underneath the span after the earthquake.

Figure 184. Photo. Longitudinal and vertical seismic forces in haunches at pier 3 of Maipú River bridge. This photo shows longitudinal and vertical seismic forces in the haunches at pier 3 in the Maipú River bridge. Some concrete diaphragms were cracked significantly due to the earthquake.

Figure 185. Photo. Damage at Romero bridge and shaft foundation supporting abutment (collapsed superstructure removed). This photo shows damage to the Romero bridge, which is over a roadway. The collapsed superstructure was already removed. Damage to shear walls and fill settlement are visible. There is a vehicle on the roadway and workers standing on the side of the road. An inset photo shows a close-up of the shaft foundation supporting the abutment.

Figure 186. Photo. Interior pier of Chada structure with 5.8- to 7.8-inch (150- to 200-mm) gap in soil transverse to bridge centerline. This photo shows a view of an interior pier of the Chada structure. There is a 5.8- to 7.8-inch (150- to 250-mm) gap in the soil transverse to the bridge centerline, which is probably due to foundation and column rocking during shaking.

Figure 187. Photo. East abutment of Chada structure showing large pavement crack directly below bridge centerline. This photo shows an underside view of the east abutment of the Chada structure. There is a large crack in the pavement directly below the bridge centerline, which is possibly due to transverse foundation rocking. There is metal scaffolding below the bridge.

Figure 188. Illustration. Fill slumping observed for bridge sites 7 and 8. This illustration shows fill slumping that was observed for bridge sites 7 and 8. A solid line shows the fill line before the earthquake, and a dotted line below the solid line shows the fill line after the earthquake.

Figure 189. Photo. Fill slumping observed at Romero bridge. This photo shows the fill slumping at the Romero bridge. Severe fill settlement and shear wall failure are visible.

Figure 190. Photo. View of roadway fill failure from abutment of Route 5 railway crossing at Hospital. This photo shows a view of an abutment of site 10 at the Route 5 railway crossing at Hospital. Roadway fill failure and lateral movement is visible.

Figure 191. Photo. Close-up of approach fill failure and damaged sign bridge. This photo shows a close-up view of the railway bridge approach. Fill failure is visible by cracking in the roadway. Additionally, there is a damaged overhead road sign. One leg of the sign bridge appears to be falling over.

Figure 192. Photo. Lateral spreading at Mataquito bridge. This photo shows lateral spreading at Mataquito bridge. Lateral movements occurred at the northeast end of the structure and involved the abutment fill and gently sloping ground to the river bank. Markings on the photo indicate approximately 6.6 to 8.2 ft (2 to 2.5 m) of lateral spreading and approximately 4.9 to 5.9 ft (1.5 to 1.8 m) of movement of the ground.

Figure 193. Photo. Lateral spreading at Mataquito bridge with lateral movement beneath and around bridge. This photo shows lateral spreading beneath and around the Mataquito bridge. The edge of the earth is highlighted where it meets the water. Text on the photo says "Lateral spreading lobes 'pooched out' on both sides of the bridge, but not directly under bridge."

Figure 194. Photo. Lateral spreading and ground failure at old Ramadillas bridge. This photo shows an underside view of the old Ramadillas bridge. Lateral spreading in both directions and ground failure are visible. Soil is pressed up against the pier due to spreading.

Figure 195. Photo. Sand boils at southwest end of Llacolen bridge. This photo shows sand boils at the southwest end of the Llacolen bridge. The boils, which are labeled with red arrows, were created as a result of liquefaction. Three cement columns of the bridge are also visible.

Figure 196. Photo. Ejected sand due to liquefaction and ground failure at La Mochita bridge. This photo shows a view of the underside of the La Mochita bridge. Ejected sand due to liquefaction and ground failure are visible underneath the bridge. An arrow points to the right, indicating the direction of movement.

Figure 197. Photo. Severe ground failure at La Mochita bridge. This photo shows severe ground failure below the La Mochita bridge. A pier settled and moved laterally. An arrow pointing to the right indicates the direction of ground movement toward a body of water. Arrows also point to the slope crest and reverse scarps. There are large cracks in the ground below the bridge.

Figure 198. Photo. Lateral spreading and ground failure at Raqui 2 bridge. This photo shows lateral spread and ground failure at the Raqui 2 bridge. Fill settlement relative to the bridge pier and lateral spreading of the approach fill are visible. There is crumbling in the concrete on the sides of the bridge.

Figure 199. Photo. San Nicolás bridge center pier settlement probably due to liquefaction of soil layers beneath river. This photo shows the San Nicolás bridge center pier over a river. The center pier in the river has settled; however, because of the water in the river, no specific evidence of liquefaction was observed.

Figure 200. Photo. Ramps at Juan Pablo II bridge where existing ground was improved with DDC. This photo shows ramps at the Juan Pablo II bridge. Arrows point to vertical settlement of the fill and ground cracks. The only ground improvement used to help address liquefaction was the use of deep dynamic compaction (DDC) beneath some of the ramp approach fills near the north end of the bridge.

Figure 201. Photo. Lateral movement of fill in ramps at Juan Pablo II bridge. This photo shows another view of the ramps at the Juan Pablo II bridge. Ground cracking in the slope of the bridge is visible. Additionally, lateral movement of the fill has compressed and crumpled the guardrail on the right side of the ramp. A worker is observing the damage from the roadway.

Figure 202. Photo. Abutment fill settlement of northeast abutment of Mataquito bridge. This photo shows the northeast abutment of the Mataquito bridge. Fill settlement of approximately 2.3 to 2.9 ft (0.7 to 0.9 m) is visible. Additionally, there is minor compression damage to the abutment wall. Below the bridge, soil appears to be pushed up 0.7 to 1 ft (0.2 to 0.3 m).

Figure 203. Photo. Soil settlement without bridge settlement at northeast abutment of Mataquito bridge. This photo shows the northeast abutment of the Mataquito bridge. There is soil settlement between 1.6 to 3.3 ft (0.5 and 1.0 m) on the right side of the bridge. There is a worker standing on the right side of the bridge observing the damage.

Figure 204. Photo. Soil settlement at interior pier at northeast abutment of Mataquito bridge. This photo shows the underside of the northeast abutment and pier of the Mataquito bridge. Three columns are visible with red arrows at their bases, showing soil settlement at the interior pier. The first column on the left has soil settlement of 1.6 ft (0.5 m).

Figure 205. Photo. Abutment fill settlement at northwest abutment of Raqui 1 bridge. This photo shows a side view of the northwest abutment of the Raqui 1 bridge. Girders are jammed against the abutment wall, and there is fill settlement along the bank of the bridge.

Figure 206. Photo. Abutment and girders shoved into each other and deck at the northwest abutment of the Raqui 1 bridge. This photo shows an underside view of damage to the northwest abutment of the Raqui 1 bridge. Girders and the deck are jammed against the abutment wall, and the concrete gravity wall was tilted and displaced.

Figure 207. Photo. Raqui 1 bridge viewed from north side. This photo shows a view of the Raqui 1 bridge, which runs horizontally across the photo. The bridge crosses over a body of water, and soil with cracks is in front of the bridge. The soil cracking pattern suggests lateral movement northeast toward the river.

Figure 208. Photo. Evidence of ground failure perpendicular to roadway centerline at northwest approach of Raqui 1 bridge. This photo shows the Raqui 1 bridge from the northwest approach fill. The direction of soil movement is to the left, and there is lateral ridging due to ground failure.

Figure 209. Map. Aerial view of Biobío River and crossings. This photo shows an aerial view of the Biobío River. The water flows from the bottom of the photo toward the top. Several bridges are labeled from north to south including the Juan Pablo II bridge, the railroad crossing, the Llacolen bridge, the Biobío bridge, and the La Mochita bridge. Red arrows on the right bank of the river indicate observed liquefaction-induced slope failure.

Figure 210. Photo. Evidence of slope instability due to liquefaction at northeast abutment and approaches of Llacolen bridge. This photo shows a side view of the Llacolen bridge. Circles indicate locations of observed ground cracks and settlement.

Figure 211. Illustration. Plan view of liquefaction-induced slide at northeast abutment of Llacolen bridge. This illustration shows a plan view and dimensions of liquefaction-induced slide at the northeast abutment of the Llacolen bridge and its effect on the bridge and ground surrounding the bridge.

Figure 212. Photo. Settlement due to liquefaction-induced slope instability at northeast end of Llacolen bridge. This photo shows the northeast end of the Llacolen bridge. One side of the superstructure is detached from the pier supporting the bridge. Arrows on the photo point to ground cracks and settlement as well as gaps in front of the pier shafts.

Figure 213. Photo. Settlement and lateral ground movement of interior pier at northeast end of Llacolen bridge. This photo shows the northeast end of the Llacolen bridge. Labels mark a fallen span and the location of soil settlement of 1.3 ft (0.4 m) and lateral movement of 0.82 ft (0.25 m). There is an arrow pointing to the left, indicating the location of the river relative to the bridge.

Figure 214. Photo. Lateral ground and foundation movement at interior pier and fallen span at northeast end of Llacolen bridge. This photo shows the northeast end of the Llacolen bridge. An arrow points to slope cracks at an interior pier. There was lateral ground and foundation movement at the pier, causing a span to fall toward the river.

Figure 215. Photo. Close-up of cracked column at northeast end of Llacolen bridge. This photo shows a close-up of a cracked column at the northeast end of the Llacolen bridge. The crack runs horizontally across the cylindrical column.

Figure 216. Photo. Wall settlement due to slope movement and instability caused by liquefaction at northwest end of Chepe railroad bridge. This photo shows the section of the Chepe railroad bridge that crosses over a roadway. Arrows show displacement of the railing and wall. The roadway settled approximately 4.3 ft (1.3 m). There are vehicles driving on the roadway, and workers are standing to the right of the roadway observing the damage.

Figure 217. Photo. Settlement of approach structure for Juan Pablo II bridge. This photo shows a view of the Juan Pablo II bridge. Arrows point to the south wall as well as a pier supporting an approach structure that settled. The wall did not settle.

Figure 218. Photo. Close-up of settlement of approach structure for Juan Pablo II bridge. This photo shows a close-up of the approach structure settlement of the Juan Pablo II bridge. Arrows point to the bridge settlement and the south wall.

Figure 219. Photo. Roadway settlement due to settlement of approach structure pier foundations for Juan Pablo II bridge. This photo shows the Juan Pablo II bridge. Roadway settlement due to settlement of the pier foundations supporting the approach structure is visible.

Figure 220. Photo. Roadway settlement due to settlement of mainline pier foundations for Juan Pablo II bridge. This photo shows the Juan Pablo II bridge. Roadway settlement due to settlement of the pier foundations supporting the mainline is visible.

Figure 221. Photo. Liquefaction-induced differential settlement of mainline pier foundations supporting Juan Pablo II bridge. This pair of photos shows the underside of the Juan Pablo II bridge. In the left photo, arrows point to differential settlement across the bridge piers. In the right photo, arrows point to cracking and exposed reinforcement of the columns.

Figure 222. Photo. Damage to pier columns for mainline Juan Pablo II bridge. This photo shows damage to pier columns of the Juan Pablo II bridge. An arrow points to one of the failed columns. The direction of slope movement is to the right, toward the river. Workers are observing the damage to the bridge.

Figure 223. Photo. View of collapsed spans from northeast river bank of Biobío River. This photo shows some of the collapsed spans of the old Biobío River bridge. The collapsed spans and piers were probably caused by poor lateral soil support during strong shaking and possibly due to liquefaction-induced lateral soil movement or liquefaction-induced loss of lateral foundation support.

Figure 224. Photo. Close-up of old Biobío River bridge showing exposed pile foundations. This photo shows some of the exposed piles of the Biobío River bridge. The exposed piles are located directly below the collapsed spans.

Figure 225. Photo. Ground failure near northeast abutment of old Biobío River bridge. This photo shows the northeast side of the old Biobío River bridge. A large crack in the soil indicates ground failure near the northeast abutment of the bridge.

Figure 226. Photo. Tilting of northeast abutment pier wall of old Biobío River bridge. This photo shows the underside of the old Biobío River bridge. An arrow pointing to the left indicates the direction of lateral movement of the girders. An arrow pointing to the right indicates outward rotation of an abutment wall. There is tilting of the northeast bridge abutment.

Figure 227. Photo. Ground failure of north approach fill for La Mochita bridge. This photo shows ground failure of the north approach fill for the La Mochita bridge. There are severe cracks and damage to the soil. Workers are observing the damage.

Figure 228. Photo. La Mochita bridge north approach fill liquefaction-induced ground failure. This photo shows the north approach of the La Mochita bridge. There is liquefaction-induced ground failure. There are large cracks and damage to the bridge near the railing on the right side.

Figure 229. Photo. La Mochita bridge north approach fill and edge of dredging pit. This photo shows a view of the north approach of the La Mochita bridge. The Biobío River is to the right of the bridge. An arrow pointing to the left indicates a dredging/sluicing operation.

Figure 230. Photo. La Mochita bridge deck and girder lateral movement. This photo shows a view of the La Mochita bridge deck. Labels indicate areas of minor bridge deck settlement and lateral bridge deck movement.

Figure 231. Photo. La Mochita bridge deck and girder lateral movement and approach fill settlement. This photo shows a view of the La Mochita bridge deck. An arrow points to lateral bridge deck movement. The pavement is warped and cracked near the approach to the bridge. There are workers standing on the bridge.

Figure 232. La Mochita bridge lateral bridge deck and girder at south abutment. This photo shows the underside of the La Mochita bridge at the south abutment. There is an arrow pointing to the left, indicating the direction of lateral movement of girders. A circle indicates the location of a girder that almost slipped off the bridge deck.

Figure 233. Photo. Southeast approach fill damage at Raqui 2 bridge. This photo shows the southeast approach of the Raqui 2 bridge. There is fill damage due to liquefaction at the base of the bridge and approximately 4.9 ft (1.5 m) of approach fill settlement.

Figure 234. Photo. Collapsed and shifted spans at Raqui 2 bridge as viewed from base of southeast abutment. This photo shows a side view from the southeast abutment of the Raqui 2 bridge. The span shifted to the left while the pier wall did not move, causing the bridge to collapse.

Figure 235. Photo. Collapsed and shifted spans at Raqui 2 bridge due to liquefaction. This photo shows collapsed and shifted spans of the Raqui 2 bridge. The tilted substructure fell into the water below, and the corner of the span on the right is resting on the span on the left.

Figure 236. Photo. South approach fill damage and collapsed spans at Tubul bridge. This photo shows damage to the south approach of the Tubul bridge. Fill damage and collapsed spans due to liquefaction are visible.

Figure 237. Photo. Settlement of fill beside the south abutment of Tubul bridge. This photo shows settlement of the fill next to the south abutment of the Tubul bridge. The right side of the bridge appears to be detached and settled into the soil.

Figure 238. Photo. Overview of damage to south abutment of Tubul bridge. This photo shows an overview of the abutment damage of the Tubul bridge. A timber pile and damage to a pile cap are visible.

Figure 239. Photo. Close-up of exposed pile and pile cap damage on south abutment of Tubul bridge. This photo shows a close-up of a timber pile and damage to a pile cap of the Tubul bridge.

Figure 240. Photo. Overview of Tubul bridge north abutment. This photo shows a view of the north abutment of the Tubul bridge. Labels indicate areas where the abutment and the girder were shoved together and where there was approach fill settlement and movement. Cracks due to lateral spreading on the ground next to the bridge are visible.

Figure 241. Photo. Tubul bridge collapsed spans and substructure. This photo shows collapsed spans and substructure of the Tubul bridge as viewed from the north end of the bridge. The spans of the bridge have separated from one another and appear jagged.

Figure 242. Photo. Puerto de Coronel Muelle foundation displacement and bending. This photo shows the underside of the Puerto de Coronel Muelle foundation. Lateral soil movement forced the pile over.

Figure 243. Photo. Close-up of Puerto de Coronel Muelle foundation displacement and bending. This photo shows a close-up view of the Puerto de Coronel Muelle foundation displacement. Bending of a support beam is visible, which was caused by liquefaction and lateral spreading. Two workers are next to the bent foundation.

Figure 244. Photo. View northeast from Tubul bridge south abutment showing areas left dry and boats left above the new mean water level. This photo shows a view from the Tubul bridge south abutment. An arrow pointing left indicates the direction of lateral spreading. The photo shows areas that were once under water and are now dry. Boats have been left behind and are now above the new mean water level.

Figure 245. Photo. Tubul bridge with boats run through by old timber pilings. This photo shows a view of the Tubul bridge. The spans of the bridge are separated from one another. There is a damaged boat hanging on old timber pilings.

Figure 246. Photo. Retaining wall at Américo Vespucio/Miraflores. This photo shows the retaining walls that support the sides of the bridge abutment for the Américo Vespucio/Miraflores bridge.

Figure 247. Photo. Retaining wall at Américo Vespucio/Lo Echevers. This photo shows the retaining walls that support the sides of the bridge abutment for the Américo Vespucio/Lo Echevers bridge

Figure 248. Photo. Retaining wall at 14 de la Fama. This photo shows the retaining walls that support the sides of the bridge abutment for the 14 de la Fama bridge.

Figure 249. Photo. Retaining wall Quilicura railroad overcrossing. This photo shows the retaining walls that support the sides of the bridge abutment for the Quilicura railroad overcrossing bridge.

Figure 250. Photo. Retaining walls at Américo Vespucio/Independencia eastbound. This photo shows the modular block-faced retaining walls that support the sides of the bridge abutment for the Américo Vespucio/Independencia interchange eastbound bridge.

Figure 251. Photo. Retaining wall at Américo Vespucio/Independencia westbound. This photo shows the abutment retaining walls that support one of the ramps at the Américo Vespucio/Independencia interchange.

Figure 252. Photo. Retaining wall at Maipú River bridge. This photo shows the abutment walls that support the railroad bridge over the Maipú River.

Figure 253. Photo. Retaining wall at Estribo Francisco Mostazal (Avenida Independencia). This photo shows the modular block-faced geogrid wall that supports the abutment foundation for the Estribo Francisco Mostazal (Avenida Independencia) bridge

Figure 254. Photo. Retaining wall at Chepe railroad bridge over Biobío River. This photo shows the retaining wall that provides a grade separation between the roadway and the bridge pier and Biobío River for the Chepe railroad bridge.

Figure 255. Photo. Retaining wall at Raqui 2. This photo shows the walls that support the sides of the Raqui 2 bridge.

Figure 256. Photo. South retaining wall at Juan Pablo II. This photo shows the south wall that supports the sides of the bridge approach for the Juan Pablo II bridge.

Figure 257. Photo. North retaining wall at Juan Pablo II. This photo shows the north wall that supports the sides of the bridge approach for the Juan Pablo II bridge.

Figure 258. Photo. Retaining wall at 21 de Mayo. This photo shows one of the retaining walls that support the sides of the abutment at the 21 de Mayo Interchange.

Figure 259. Photo. Retaining wall at Rotonda General Bonilla. This photo shows the geogrid block-faced wall supporting the sides of the abutment at the Rotonda General Bonilla bridge.

Figure 260. Photo. Retaining wall at Muros Talca (SW). This photo shows the block-faced geogrid walls that support the sides of the bridge abutment at Muros Talca (SW).

Figure 261. Photo. Toppling of coping at Américo Vespucio/Independencia. This photo shows the Américo Vespucio/Independencia site. Arrows point to a drainage ditch along the top of the wall and to an unsupported top block being held by connectors.

Figure 262. Photo. Wall movement near Chepe railroad bridge due to lateral spreading and settlement. This photo shows wall movement at site 18 due to lateral spreading and settlement. Wall segments are shown at different heights.

Figure 263. Photo. Wall settlement and rotation due to lateral spreading and settlement. This photo shows lateral spreading and settlement under site 18. Workers are observing the settlement.

Figure 264. Map. Retaining walls near Juan Pablo II bridge. This map shows an overview of site 25. Labels indicate the north and south sides of the site.

Figure 265. Photo. Wall settlement near Juan Pablo II bridge due to liquefaction-induced settlement. This photo shows a close-up of site 25. There is wall settlement and cracking in the pavement of the site due to liquefaction-induced settlement.

Figure 266. Map. Vía Elevada 21 de Mayo. This map provides an overview of site 28, Vía Elevada 21 de Mayo. A road runs diagonally across the map in the southeast-northwest direction. An arrow indicates that north is to the right side of the photo.

Figure 267. Photo. Tiered wall corner tilting outward at wall site 28A. This pair of photos shows a wall corner at wall site 28A. The left photos shows cracking in the wall. The right photo shows a tiered wall corner tilting outward.

Figure 268. Photo. Wall corner tilting outward at wall site 28B. This photo shows wall site 28B. The top of the wall moved out 1 ft (0.3 m). The bridge deck attached to the top of the wall shifted 5.9 to 7.8 inches (150 to 200 mm) toward the acute skew angle.

Figure 269. Photo. Lateral movement of lower wall top at wall site 28C. This photo shows the lateral movement of wall site 28C. A 1- to 4.6-ft (0.3- to 0.4-m) gap can be seen near the top of the lower wall.

Figure 270. Photo. Back side of upper wall at wall site 28C. This photo shows the back side of wall site 28C. A metal mesh grid is exposed, and crumbled concrete can be seen.

Figure 271. Photo. Fill material from tiered wall at wall site 28C. This photo shows a large pile of fill material spilling from a gap in the wall at wall site 28C. The angle of repose, 32 degrees, is marked on the photo.

Figure 272. Photo. Differential settlement at wall site 28C. This photo shows panel gaps that resulted due to differential settlement at wall site 28C.

Figure 273. Photo. Possible liquefaction features near wall site 28C. This photo shows possible liquefaction features near wall site 28C. There is a two-lane roadway with cracks in it. There is a railway to the right of the road.

Figure 274. Illustration. Plan view of wall at Muros Talca. This illustration shows a plan view of the interchange and walls at site 32.

Figure 275. Photo. Wall with steep top slope at Muros Talca. This photo shows a view of site 32, Muros Talca. There is a wall with a steep top slope. There is block cracking in 45-degree shear bands. There is wall face deformation up to 3.9 inches (100 mm) and a 3.9- to 5.9-inch (100- to 150-mm) gap in the wall.

Figure 276. Photo. Wall with cracked block pattern at Muros Talca. This photo shows a wall with a cracked block pattern. Diagonal lines mark the angle of the crack, 45 degrees, and a gap can be seen at the top of the wall. Workers are observing the wall.

Figure 277. Photo. Bridge supported on footing on top of block-faced geogrid wall at Estribo Francisco Mostazal. This photo shows an underside view of site 11. A bridge is supported on a footing on top of a block-faced geogrid wall.

Figure 278. Illustration. Notations on skew direction. This two-part illustration defines bridge skew. On the left is a parallelogram leaning to the right, showing a clockwise skew of the bridge centerline. On the right is another parallelogram leaning slightly left, showing a counter-clockwise skew of the bridge centerline.

Figure 279. Illustration. Deck rotation of a representative bridge (two spans shown). This illustration shows deck rotation of a bridge. The steps are as follows: 1a: longitudinal EQ effect, 1b: transverse EQ effect, 2: impact and turning counter clockwise, 3: rotational (EQ) effect, 4a: unseating, and 4b: unseating.

Figure 280. Illustration. Rotational and translational mode responses to ground motions. This graph shows a response spectrum due to the earthquake and the relative sensitivity of the rotational and translational mode responses to ground motions.

Figure 281. Photo. Exterior girder damage at Chada bridge, no diaphragms. This photo shows the damage to the underside of the Chada bridge, which had no diaphragms.

Figure 282. Photo. Exterior girder damage at San Nicolás bridge, partial diaphragms. This photo shows the damage to the underside of the San Nicolás bridge, which had partial diaphragms.

Figure 283. Photo. Exterior girder damage at west abutment of Llacolen bridge, concrete teeth. This photo shows damage to the underside of the west abutment of the Llacolen bridge, which had concrete teeth.

Figure 284. Map. Image of site 1 taken prior to earthquake. This satellite photo shows a map of site 1 prior to the earthquake. A circle marks the general location where a boring log was taken.

Figure 285. Illustration. Boring log at site 1. This illustration provides a close-up of a boring log at site 1.

Figure 286. Map. Image of site 2 taken prior to earthquake and showing approximate location of test hole. This map shows an image of site 2 taken before the earthquake. A circle indicates the approximate location of the test hole at the site.

Figure 287. Illustration. As-built bridge plan for site 2. This illustration shows an as-built bridge plan for Américo Vespucio/Lo Echevers bridges at site 2.

Figure 288. Illustration. As-built bridge profile for site 2 showing footing foundations. This illustration shows an as-built bridge profile for Américo Vespucio/Lo Echevers bridges at site 2 showing footing foundations.

Figure 289. Illustration. Boring lot at site 2. This illustration provides a close-up of a boring log at site 2.

Figure 290. Map. Image of site 7 taken prior to earthquake and showing approximate location of test hole. This map shows site 7 before the earthquake. A circle shows the approximate location of the test hole.

Figure 291. Illustration. As-built bridge plan for site 7. This illustration shows an as-built bridge plan for Avenida Romero bridge at site 7.

Figure 292. Illustration. Boring log for site 7. This illustration shows a boring log for Avenida Romero bridge at site 7.

Figure 293. Map. Image of site 8 taken prior to earthquake and showing approximate location of test hole. This map shows an image of site 8 before the earthquake. A circle shows the approximate location of the test hole.

Figure 294. Illustration. As-built bridge plan for site 8. This illustration shows an as-built bridge plan for Avenida Chada bridge at site 8 and the approximate location of the boring log illustrated in figure 293.

Figure 295. Illustration. Boring log for site 8. This illustration shows a boring log for Avenido Chada bridge at site 8.

Figure 296. Map. Image of site 10 taken prior to earthquake and showing approximate location of test hole. This map shows an image of site 10 before the earthquake. A red circle shows the approximate location of the test hole.

Figure 297. Illustration. As-built bridge plan for site 10. This illustration shows an as-built bridge plan for I-5/Paso Superior bridge at site 10 and the approximate location of the test hole shown in figure 296.

Figure 298. Illustration. Boring log SA-2 for site 10. This illustration shows boring log Sa-2 for I-5/Paso Superior bridge at site 10.

Figure 299. Map. Image of site 28 taken prior to earthquake and showing approximate locations of test holes. This map shows an image of site 28 before the earthquake. Red circles labeled S1, S2, and S2 indicate the approximate location of test holes. Arrows point to sites A, B, and C.

Figure 300. Illustration. Boring log S-1 for site 28. This illustration shows boring log S-1 for site 28.

Figure 301. Illustration. Detailed standard penetration test blow counts for boring log S-1 for site 28. This illustration shows detailed standard penetration test blow counts for boring log S-1 for site 28.

Figure 302. Illustration. Boring log S-2 for site 28. This illustration shows boring log S-2 for site 28.

Figure 303. Illustration. Detailed standard penetration test blow counts for boring log S-2 for site 28. This illustration shows detailed standard penetration test blow counts for boring log S-2 for site 28.

Figure 304. Illustration. Boring log S-3 for site 28. This illustration shows boring log S-3 for site 28.

Figure 305. Illustration. Detailed standard penetration test blow counts for boring log S-3 for site 28. This illustration shows detailed standard penetration test blow counts for boring log S-3 for site 28.

 

Equations

Equation 1. K subscript h. K subscript h equals K subscript 1 times S times A subscript o divided by 2 g which is less than or equal to 0.10.

Equation 2. K subscript h times T subscript n. When T subscript n is less than or equal to T subscript 1, K subscript h times T subscript n equals 1.5 times K subscript 1 times S times A subscript o divided by g. When T subscript n is greater than T subscript 1, K subscript h times T subscript n equals K subscript 1 times K subscript 2 times S times A subscript o divided by g times T subscript n to the two-thirds power. V subscript b is greater than or equal to 0.22 times K subscript 1 times S times A subscript o over 2 g times P.

Table 13. Equation 1. T subscript n equals 2 pi times the square root of the equation 0.3 W subscript p plus W subscript u times H to the third power divided by 0.3 E subscript c times I times g.

Table 13. Equation 2. T subscript n equals 2 pi times the square root of the equation 0.3 W subscript p plus W subscript u times H to the third power divided by 0.3 E subscript c times I times g.

Table 13. Equation 3. T subscript n equals 2 pi times the square root of the equation 0.3 W subscript p plus W subscript u times H to the third power divided by 4.5 E subscript c times I times g.

Table 13. Equation 4. T subscript n equals pi over 8 times the square root of the equation W subscript p times H to the third power over E subscript c times I times g.

Equation 3. S subscript a. When T subscript m is less than or equal to T subscript 1, S subscript a times T subscript m equals 1.5 times K subscript 1 times S times A subscript o. When T subscript m is greater than T subscript 1, S subscript a times T subscript m equals K subscript 1 times K subscript 2 times S times A subscript o divided by T subscript m to the two-thirds power. V subscript b is greater than or equal to 0.20 times K subscript 1 times S times A subscript 0 times P over g.

Equation 4. S. S equals the square root of the summation i summation j rho subscript i j S subscript i S subscript j.

Equation 5. rho subscript i j. rho subscript i j equals 8 times xi square times r to the 3/2 power over open parenthesis 1 plus r close parenthesis open parenthesis 1 minus r close parenthesis squared plus 4 xi squared r times open parenthesis 1 plus r close parenthesis. r equals T subscript i over T subscript j which is less than or equal to 1.0.

Equation 6. F. F equals 100 percent F subscript L plus 30 percent F subscript T.

Equation 7. F. F equals 30 percent F subscript L plus 100 percent F subscript T.

Equation 8. N. N equals open parenthesis 203 plus 1.67 L plus 6.66 H close parenthesis times open parenthesis 1 plus 0.000125 alpha squared close parenthesis (in mm).

Equation 9. N. N equals open parenthesis 305 plus 2.5 L plus 10 H close parenthesis times open parenthesis 1 plus 0.000125 alpha squared close parenthesis. (in mm).

Equation 10. 1.0 times open parenthesis D plus B plus SF plus E plus EQM close parenthesis.

Equation 11. S subscript j. S subscript j is greater than or equal to 6.25 times A subscript o over g plus S subscript 1 plus S subscript 2 (in cm).

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United States Department of Transportation - Federal Highway Administration