| Goal #1 - Assess staging areas: close pedestrian path and pedestrian bridge |
For improved contractor accessibility, reduced risked to pedestrians, reduced cost, reduced roadway bridge closure time, and improved site security, close during demolition and construction. |
Barriers:
- Public desire for pedestrian access during demolition and construction.
- Pedestrian trail will dead end at bridge.
- Need to provide comfort facilities for play fields.
Coordination:
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| Goal #1 - Assess staging areas: close roadway bridge |
For improved contractor accessibility, reduced risk to motorists, reduced cost, and reduced roadway bridge closure time, close during demolition and construction. |
Barriers:
- Pedestrian access and uncertain isolated pedestrian routes, including students walking to and from school.
- May require busing of students.
Coordination:
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| Goal #2 - Assess construction staging: close roadway bridge |
Eliminates the risk and uncertainty of the stability of the existing structure during demolition and staged construction. Also removes all traffic loads. |
Barriers:
- Impact to commuters, community access.
Coordination:
- Traffic/MOT.
- Public Relations.
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| Goal #2 - Assess construction staging: modify shoring system |
To speed staged construction, longitudinally post tension retaining wall along full length of structure, instead of tieback system shown to eliminate demolishing portions of the existing structure. |
Barriers:
- Still risky and needs further evaluation.
Coordination:
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| Goal #2 - Assess construction staging: eliminate maintaining pedestrian traffic on bridge during staged construction |
Eliminates two stages of construction to speed construction schedule. |
Barriers:
- Needs further evaluation.
Coordination:
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| Goal #3 - Material Availability: use bulb tee beams |
Precast concrete beam fabricators no longer readily have forms for AASHTO beams. Bulb tees are more efficient and should cost less. Availability of bulb tees should speed construction relative to AASHTO beams. |
Barriers:
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| Goal #3 - Material Availability: eliminate 50 feet of interpretive aesthetic railing on middle span |
Reduces cost. |
Coordination:
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| Goal #4 - Use of precast components: consider use of stay-in-place precast concrete deck panels, either in lower half with CIP composite topping or full-depth |
Reduced cost, speeds construction. |
Barriers:
- Not commonly used in Maryland.
Coordination:
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| Goal #4 - Use of precast components: consider precast spread footings, abutments, wingwalls, piers, and pilasters |
Reduced cost, speeds construction. Investigate flooding issues. |
Barriers:
- Not commonly used in Maryland.
Coordination:
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| Goal #5 - Alternative staged bridge demolition: build staged temporary bridge on existing/proposed alignment |
Construct 2-lane temporary bridge after demolition of existing bridge to allow two-way traffic while the first
half of proposed bridge is constructed. Benefits include minimizing length of roadway bridge closure. |
Barriers:
- Additional cost.
- Environmental impacts with temporary piers in water.
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| Goal #6 - Alternate structure type: reduce 3-span bridge to longer main span with precast concrete arch pedestrian portal on North end only |
Significant reduction in initial cost and future maintenance cost, reduced construction time, improved pedestrian and bike access. Future roadway bridge and portal widening would be easier and less costly. |
Barriers:
- Significant redesign.
- Likely need for total roadway bridge closure.
- Maryland Historic Trust issues.
- Community acceptance would require computer renderings.
Coordination:
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| Goal #6 - Alternate structure type: simplify precast facade details |
Reduction in number of construction operations will reduce cost and speed construction. |
Coordination:
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| Goal #6 - Alternate structure type: build permanent new bridge parallel to existing alignment and leave existing roadway bridge open during bridge construction |
Benefits include allowing traffic to flow throughout bridge construction in its existing configuration, allowing new structure to be constructed in one phase, and allowing existing structure to be demolished in one phase. |
Barriers:
- Additional cost.
- Major environmental impacts.
- Temporary loss of park land.
- Tie in with existing approaches required.
Coordination:
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| Goal #6 - Alternate structure type: provide minimum 6-ft wide from curb edge to parapet wall |
To allow designation as a bike trail for short distances, a minimum 6-ft clear width is required. Benefits would include no need to widen existing roadway and roadway bridge. |
Barriers:
- Outside ornamental railing will need to be replaced with a crashtest approved parapet wall.
- Interpretative railing at mid-section must be omitted.
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| Goal #6 - Alternate structure type: if bridge is widened, add park treatments such as median and end pilasters as gateway to park |
Benefits include offsetting loss of ornamental outside railing, motorist safety increased with median separating traffic settings, traffic calming with median, and improved parkway aesthetics - greener and safer. |
Barriers:
Coordination:
- Traffic.
- Public Relations
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| Goal #7 - Single-staged demolition process (utilities accommodation): confirm that 20" and 6" water mains can be taken out of service during construction |
Reduction in number of construction operations will reduce cost and speed construction. |
Barriers:
- If water mains remain in service during construction, they will need to be temporarily supported or relocated through the park permanently.
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| Goal #7 - Single-staged demolition process: cut demolition time |
Closing the roadway bridge and the pedestrian bridge will cut demolition time more than half and decrease mobilization by half. Give contractor the option to use pedestrian bridge to assist in debris containment. |
Barriers:
- Closed bridges will impact public use.
Coordination:
- Traffic.
- Public Relations
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| Goal #8 - Temporary bridge alternates: construct new permanent pedestrian bridge east of roadway bridge prior to demolition of existing roadway bridge |
The existing pedestrian bridge will be eliminated prior to roadway bridge demolition. New pedestrian bridge recommended is a prefabricated bridge, for example, a single span steel truss. Benefits include improved safety for pedestrians, reduced construction time and cost, elimination of the view of main span from below, and elimination of future conflicts of pedestrian bridge under roadway bridge. |
Barriers:
- Funding source for removal of existing pedestrian bridge and construction of new pedestrian bridge needs to be determined.
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| Goal #8 - Temporary bridge alternates: reconstruct approach roadway the entire length on both ends within the retained fill sections, possibly with a wider cross section |
Makes life-cycle of retained fill sections consistent with new roadway bridge, reduces maintenance, improves consistency of aesthetic design throughout the entire park, and allows widening of bridge width for sidewalks, bike path, and additional width to separate two-directional traffic. |
Barriers:
- Savings in project cost from other recommendations will be offset by cost of approach roadway reconstruction.
- Increases the limits of disturbance of the project and, therefore, the environmental impacts.
Coordination:
- Environmental coordination required if new retained fill sections are widened.
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| Goal #8 - Temporary bridge alternates: build temporary detour bridge parallel to existing/proposed alignment |
The use of a temporary detour bridge needs to be evaluated for number of lanes, pedestrian needs, and alignment for service throughout roadway bridge construction. |
Barriers:
- Cost prohibitive.
- Major environmental impacts.
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| Goal #9 - Construction management techniques: contracting strategies to consider include P-P-P, D-B, incentive/disincentive, A+B bidding, performance specifications |
Benefits include speed construction, increase contractor innovation, increase likelihood of early completion, improve longterm performance of structure, better utilization of contractor resources. |
Barriers:
Coordination:
- Construction.
- Traffic.
- Environmental.
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| Goal #10 - New materials & techniques: use high performance concrete |
Benefits include improved longterm performance of components, possible reduced cost of materials. |
Coordination:
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