Construction

Construction Program Management and Inspection Guide

Appendix B (Part 3 continued)

7.0 Field Management

The activities and procedures to be followed for QC during placement of Earthwork materials are as indicated below.

7.1 - Schedule of Field Placement Operations

ABC Contractors will provide Transportation Agency with a "Weekly Schedule of Earthwork Materials Placement Operations" on each Friday prior to the week of placement. A copy of the "Weekly Schedule of Earthwork Materials Placement Operations" is located in Appendix __ (see Note in "A Model Quality Control Plan"). The weekly schedule of Placement Operations will identify the following:

• Project Segment
• Placement Location
• Maximum Placement Depth
• Intended Placement Locations (Roadway, Station Limits)
• Material Type(s)
• Estimated Placement Quantities
• Material Source(s)

ABC Contractors will track the actual placement quantities on a daily basis and maintain a "Record of Earthwork Placement" for each week. Copies of the "Record of Earthwork Placement" will be made available to Transportation Agency.

7.2 - Field Placement Facilities and Equipment

ABC Contractors will utilize conventional facilities and equipment for the placement of all Earthwork materials. The major types of facilities and equipment to be utilized for Earthwork placement are summarized below for each type of Earthwork Item.

7.3 - Establishment of Compaction Rolling Pattern (Control Strips)

Control Strips will be constructed at the start of each Earthwork placement operation. A new Control Strip will be constructed whenever one of the following occurs:

• A new Earthwork Lot
• A change in weather
• A change in environment
• A PWL < 85% for 3 or more consecutive QC Test Results

The Control Strips will be used to establish an effective rolling pattern and the corresponding compactive effort required to achieve the in-place Target Density (Maximum Dry Density) at Optimum Moisture Content. The procedure to be followed for developing a Control Strip is outlined as follows:

7.3.1 - Earthwork Compacted by Rollers

Step A. - The Control Strip will be established on the first lift to be constructed within an area not to exceed 30m long by 15m wide. The Strip will be divided longitudinally into 3 approximately equal Control Strip Sections.
Step B. - Material will be loose placed in the first Control Strip Section. The Field Superintendent, Roller Operator(s) and QC Field Inspector will visually assess the moisture content of Earthwork placed and determine whether additional moisture is needed to achieve Optimum Moisture Content.
Step C. - The Field Superintendent, Roller Operator(s) and QC Field Inspector will discuss and agree upon the proposed number and sequence of passes and compactive mode(s) (static, vibratory) to be used for the particular Earthwork being placed.
Step D. - The Roller Operator(s) will compact Control Strip Section #1 following the agreed upon number and sequence of passes and compactive mode(s).
Step E. - After compacting Control Strip Section #1, the Roller Operator will suspend operation. The QC Inspector will perform Contractor Information Testing (CIT) within Control Strip Section #1and obtain a minimum of three separate (Random or Non-Random) In-Place Density and Moisture Content readings.
Step F. - The Field Superintendent, Roller Operator(s) and QC Field Inspector will review the In-Place Density and Moisture Content readings for Control Strip Section #1 and determine any necessary adjustment to the number and sequence of passes and compactive mode(s).
Step G. - The Roller Operator will move on to Control Strip Section #2 and compact the material following the agreed upon number and sequence of passes and compactive mode(s).
Step H. - After compacting Control Strip Section #2, the Roller Operator will suspend operation and permit the QC Inspector to obtain a minimum of three separate random In-Place Density and Moisture Content readings in Control Strip Section #2.
Step I. - The CIT results for Control Strip Section #2 will be evaluated by the QC Inspector using Quality Level Analysis (QLA). The QLA must indicate a Percent Within Limits (PWL) of 85% or more for the In-Place Density and Moisture Content as indicated in Section 8.1 below.
Step J. - If the PWL for Control Strip Section #2 is 85% or greater, then the number and sequence of passes and compactive mode(s) used in Control Strip Section #2 will be established as the approved "Compaction Pattern" for the remainder of the placement operation on that day.
Step K. - If the PWL for Control Strip Section #2 is less than 85%, then Steps F through I above will be repeated on segment #3.

7.3.2 - Earthwork Compacted by Hand Operated Compacters

Step A. - The Control Strip will be established on the first lift to be constructed within an area not to exceed 24m long by 1m wide. The Strip will be divided longitudinally into 3 approximately equal Control Strip Sections.
Step B. - Material will be loose placed in the first Control Strip Section. The Field Superintendent, Compactor Operator and QC Field Inspector will visually assess the moisture content of Earthwork placed and determine whether additional moisture is needed to achieve Optimum Moisture Content.
Step C. - The Field Superintendent, Compactor Operator(s) and QC Field Inspector will discuss and agree upon the proposed number and sequence of passes and compactive mode to be used for the particular Earthwork being placed.
Step D. - The Compactor Operator will compact Control Strip Section #1 following the agreed upon number and sequence of passes and compactive mode.
Step E. - After compacting Control Strip Section #1, the Compactor Operator will suspend operation. The QC Inspector will perform Contractor Information Testing (CIT) within Control Strip Section #1and obtain a minimum of three separate (Random or Non-Random) In-Place Density and Moisture Content readings.
Step F. - The Field Superintendent, Compactor Operator and QC Field Inspector will review the In-Place Density and Moisture Content readings for Control Strip Section #1 and determine any necessary adjustment to the number and sequence of passes and compactive mode.
Step G. - The Compactor Operator will move on to Control Strip Section #2 and compact the material following the agreed upon number and sequence of passes and compactive mode(s).
Step H. - After compacting Control Strip Section #2, the Compactor Operator will suspend operation and permit the QC Inspector to obtain a minimum of three separate random In-Place Density and Moisture Content readings in Control Strip Section #2.
Step I. - The CIT results for Control Strip Section #2 will be evaluated by the QC Inspector using Quality Level Analysis (QLA). The QLA must indicate a Percent Within Limits (PWL) of 85% or more for the In-Place Density and Moisture Content as indicated in Section 8.1 below.
Step J. - If the PWL for Control Strip Section #2 is 85% or greater, then the number and sequence of passes and compactive mode(s) used in Control Strip Section #2 will be established as the approved "Compaction Pattern" for the remainder of the placement operation on that day.
Step K. - If the PWL for Control Strip Section #2 is less than 85%, then Steps F through I above will be repeated on segment #3.

7.4 - Field Quality Control Activities

Field Quality Control (FQC) personnel will perform inspection, sampling, and testing of Earthwork as described below.

7.4.1 - Pre-Placement QC Activities

• Check Earthwork line and grade for conformance to the design documents.
• Ensure that all erosion control measures are in place per approved plans and specifications.
• Ensure that the existing ground has been cleared, grubbed and stripped as specified in Section 101 and 120 of the Standard Specifications, prior to the placing of any Earthwork materials.
• Verify that all vegetation and other organic material is removed within and immediately adjacent to Earthwork placement location.
• Determine that excavations have been conducted to suitable founding material and grade.
• Where Earthwork material is to be placed against existing earth slopes steeper than 1 Vertical:3 Horizontal, ensure that the slope is broken up into steps of random width in order to provide a suitable bond between the existing ground and the new material.

7.4.2 - Placement QC Activities

• Ensure that Control Strips are constructed at the start of each Earthwork placement operation and as required thereafter per Section 7.3 above.
• Ensure that stumps, rubbish, sod, or other unsuitable materials are not incorporated in the Earthwork.
• Ensure that frozen Earthwork materials are not placed and that Earthwork is not placed on material frozen to a depth of over 75 millimeters.
• Ensure that correct Earthwork material type, per Section 4.1 above, is being delivered/received at the intended placement location.
• Ensure that Earthwork is placed in successive layers of uniformly distributed material and compacted over the full width of the cross-section.
• Monitor lift placement to ensure that maximum lift thicknesses specified in Section 5.4 above are not exceeded.
• Ensure that each lift of compacted Earthwork materials is visibly crowned to allow drainage of surface water and rainwater off the surface.
• Monitor maximum Rock Size and maximum Stone Size in Earthwork materials for conformance with the requirements of Section 5.4 above.
• Ensure that where Rock Excavate is placed, all voids and interstices are filled with an appropriate clean, granular Earthwork material type identified in Section 4.1 above.
• Ensure that the placed Earthwork moisture content is near the optimum moisture content established through Source Characterization testing (Section 4.2 above) and through the Control Strip (Section 7.3 above).
• Ensure that moisture is added when Earthwork material is too dry and that Earthwork which is too wet is dried by disking, harrowing, blading, rotary mixing, or other approved means so that proper compaction can be achieved.
• Monitor compaction patterns against the approved Control Strip "Compaction Pattern" and perform Contractor Information Testing (CIT) to ensure that the in-place density is near the target (100%) in-place density.
• Ensure that no rock in excess of 150 millimeters in its largest dimension is incorporated in the top 600-millimeter layer of Earthwork immediately below the finished Subgrade elevation.
• Perform check measurements during placement of Roadway Embankment Material final Subgrade Course (Special Borrow) in accordance with Section 170.61 of the Standard Specifications to ensure proper depth and elevations of finished Subgrade within +/-15 millimeters.
• Ensure that Roadway Embankment Material 3 meters or more in height from the elevation of the Subgrade to the original ground elevation is constructed to the elevation of the proposed Subgrade and then allowed to settle for 60 days (or other period as specified by the Design Engineer) before the pavement structure is constructed thereon.
• Ensure that Embankment Material Under Bridge Foundations is placed in embankment prior to driving piles.
• Determine and document random sampling locations for each Sublot of Earthwork material placed.
• Obtain and properly label all Field samples of Earthwork materials.
• Transport Earthwork Field samples to the appropriate laboratory for testing.
• Perform In-Place QC sampling and testing of Earthwork in accordance with the required test methods and frequencies outlined in Section 5.0 above.
• Prepare and sign standard Test Report Forms (TRFs) for each test completed.
• Maintain Control Charts per Section 7.5 below.
• Document On-Site Earthwork QC inspection activities and findings on standard QC Inspection Report Forms (IRFs) for each On-Site placement location per Section 7.7 below.
• Identify On-Site Field placement practices or materials which do not conform with the requirements of the relevant specifications and this QC Plan, and discuss appropriate corrective action with the Segment Field Superintendent and the QC Manager.

7.5 - Placement Control Charts

Control Charts may be used by ABC Contractors to control placement operations for each of the five Earthwork Item categories as described below.

7.5.1 - Control Charts for Backfill Material for Muck Excavation

Since the placement of Backfill Material for Muck Excavation will generally involve smaller Earthwork quantities at sporadic locations, the application of Control Charts as a tool to provide field control for this Earthwork Item will yield limited QC information. Accordingly, Control Charts will not be used for placement of Backfill Material for Muck Excavation.

7.5.2 - Control Charts for Roadway Embankment Material

The placement of Roadway Embankment Material will involve large quantities of Earthwork within each Project Segment. Accordingly, Control Charts will be used as a tool to assist in the field control for placement of this Earthwork Item. Control Charts will be maintained for each Lot of Roadway Embankment Material by the QC Field Inspection staff. Control Charts will monitor the In-Place Density and Moisture Content of each Lot. The Mean QC Test results will be plotted according to daily subgrouping.

7.5.3 - Control Charts for Embankment Material Under Bridge Foundations

The placement of Embankment Material Under Bridge Foundations will involve large quantities of Earthwork within each Project Segment. Accordingly, Control Charts will be used as a tool to assist in the field control for placement of this Earthwork Item. Control Charts will be maintained for each Lot of Embankment Material Under Bridge Foundations by the QC Field Inspection staff. Control Charts will monitor the In-Place Density and Moisture Content of each Lot. The Mean QC Test results will be plotted according to daily subgrouping.

7.5.4 - Control Charts for Backfill Material for Structures

Since the placement of Backfill Material for Structures will generally involve smaller Earthwork quantities at various locations, the application of Control Charts as a tool to provide field control for this Earthwork Item will yield limited QC information. Accordingly, Control Charts will not be used for placement of Backfill Material for Structures.

7.5.5 - Control Charts for Backfill Material for Pipes

Since the placement of Backfill Material for and Pipes will generally involve smaller Earthwork quantities at various locations, the application of Control Charts as a tool to provide field control for this Earthwork Item will yield limited QC information. Accordingly, Control Charts will not be used for placement of Backfill Material for Pipes.

An example of the types of Control Charts which will be used for Earthwork placement is contained in Appendix __ (see Note in "A Model Quality Control Plan").

7.6 - Procedures for Corrective Action of Non-Conforming Materials

The following procedures will be followed for corrective action of non-specification materials encountered during placement of Earthwork Items:

• If the Earthwork material delivered/received at the placement location is not the correct Material Type (i.e. Earth Excavate, Ordinary Borrow, Special Borrow, etc.), it will be removed (if placed) and returned to the material source.
• If the Earthwork material delivered/received at the placement location is determined to be the correct Material Type, but does not meet specification requirements (e.g. gradation), the limits of such material will be determined and it will be removed from the Project. Further receipt and placement of Earthwork material from the source will be suspended until Quality Control personnel have determined and corrected the cause of non-specification material.
• If new Earthwork material delivered/received at the placement location is commingled with existing On-Site non-specification material (e.g. Organic material, Other), the limits of the commingled area will be determined and the commingled material will be removed and disposed of at an approved Off-Site location.
• If rock contained in Earthwork material is determined to exceed the specified size limits (e.g. Earth Excavate: <600 mm), appropriate equipment will be used to break the rock to conform to the maximum size requirements, or the rock will be removed and disposed of at an approved Off-Site location.
• If the percentage of rock contained in Earthwork material is determined to exceed the specified limit (e.g. Earth Excavate: < 50%), the material will either be spread and blended with other material to conform with requirements or it will be removed.
• If the lift thickness of Earthwork material is determined to exceed the specified limits, the lift will be cut using appropriate equipment and regraded to conform to the maximum lift thickness requirements.
• If an individual QC test result for in-place density or in-place moisture content is outside the Engineering Limits contained in Section 8.6 below, placement of Earthwork material in the corresponding Sublot will be stopped. The following steps will be taken:
  • A Re-Test within 300 mm of the original random test location may be performed only if the cause of the results is believed to be due to sampling/testing error.
  • If a Re-Test is not warranted, or if a Re-Test is performed and the test results of the Re-Test are also outside the Engineering Limits, then three (3) additional random QC tests may be performed within the Sublot. The results of the 3 additional random QC tests will be evaluated as follows:
    • If all three tests are above the Lower Engineering Limit (95%), then the Sublot will be accepted and all of the test results (the original failing result + the 3 passing results) will be included for Quality Level Analysis.
    • If any one of the 3 additional random QC tests is below the Lower Engineering Limit (95%), then the Sublot will not be accepted. Field QC personnel will troubleshoot to determine if the failing results are due to:
    • Improper compaction procedure
    • Inadequate moisture content
    • Other
    • Once the cause of the failing test results is determined, appropriate corrective action will be taken (e.g. Add moisture, Regrade and compact). The failing Earthwork material will be reworked and three additional random QC tests will be performed for the Sublot. The results of the 3 additional random QC tests will be evaluated in accordance with the steps above until all 3 additional test results are within the Engineering Limits and the overall Percent Within Limits (PWL) for the Sublot equals or exceeds 85%.
  • Earthwork material that cannot be reworked to achieve the specified in-place density and in-place moisture content will be disposed of Off-Site.

7.7 - Field QC Inspection Reporting

All FQC inspection activities will be documented on the following standard QC Inspection Report Forms (IRFs):

* For Off-Site Earthwork Producer material only

A copy of the Standard IRFs used for Field QC inspection of Earthwork materials is located in Appendix __ (see Note in "A Model Quality Control Plan").