573.01 Description.
572-B Soldier Pile Retaining Wall, * , **– per square feet * “Temporary”, “Permanent”, or “with Permanent Ground Anchors” ** Wall Identification, if required. (i.e. Number 1, Number 2, etc.) AGGREGATE FOUNDATIONS
573.01 Description.
This work shall consist of designing and constructing aggregate foundations at the locations shown on the Plans. The aggregate foundations are also referred to as either "stone column" foundations or "compacted aggregate" foundations.
573.02 Materials.
Unless approved otherwise by the Engineer, the aggregate for aggregate foundations shall be Number 410 coarse aggregate meeting the requirements given in Section 801.
573.03 Design Requirements for Aggregate Foundations.
The Contractor shall be responsible for insuring that the size, pattern, and spacing of the aggregate foundations are adequate to provide the required bearing capa city, settlement control, and global slope stability. The Contractor shall be fully responsible for all assumptions made about the strength of the soil and rock and all implications that the properties of the soil and rock have on the design, constructabil ity and stability. The design of the aggregate foundations shall meet the requirements given in the AASHTO Standard Specifications for Highway Bridges. These requirements shall include the following:
1.A minimum factor of safety of 1.3 against global slope s tability failure as outlined in FHWA Manual FHWA -SA-98-086R;
2.A minimum factor of safety of 1.5 against sliding failure;
3.The theoretical settlement shall not exceed two inches as measured from the retaining wall bearing elevation;
4.A minimum factor of safety of 3.0 against bearing capacity failure.
573.04 Submittal of Designs, Details and Construction Procedures.
a.Initial Submittal. The Contractor shall submit 3 sets of design calculations, foundations details and construction procedures to the Engineer as an initial submittal. This submittal shall be made within 30 calendar days after the date of the "Notice to Proceed". If clarifications are required, one set will be returned to the Contractor with comments for clarification. The initial submittal will be returned to the Contractor for clarification within 14 calendar days after the receipt of the initial submittal. The Contractor will be allowed 10 calendar days for each clarification of the initial submittal and the Engineer will be allowed 10 calendar days to determine if further clarification is necessary. The Engineer will not approve the submittal of the design calculations, foundations details and construction procedures but will review the submittal for completeness. The initial submittal of the d esign calculations, foundations details and construction procedures shall be sealed by a Licensed Professional Engineer licensed in the State of Alabama.
b.Final Submittal. When the Engineer informs the Contractor that the design calculations, foundations details and construction procedures are complete, the Contractor shall submit 5 sets of calculations and drawings and a Mylar sepia set of the drawings as a final submittal. The Contractor will be allowed 5 calendar days to make the final submittal. The Contractor shall not begin foundation construction or incorporate materials into the work until the Engineer returns one set of the completed design calculations, foundations details and construction procedures to the Contractor. This final submittal shall be sealed by a Licensed Professional Engineer licensed in the State of Alabama.
573.05 Approved List of Aggregate Foundation Specialty Contractors.
c.Minimum Requirements for the Submittal of Design Calculations.
1.Configuration of the Design Submittal. The design calculation sheets shall have the projec t number, foundation locations, initials of preparer, and page number at the top of each page. An index page shall be included to provide a list of the pages of the design calculations. The design calculations shall include an explanation of all symbols on the calculations, a description of computer programs used in the design, and at least one hand calculation documenting the computer program results. The design calculations shall indicate the target minimum replacement ratio at each section.
2.Diagram s of the Critical Cross Sections. The design calculations shall include diagrams of the critical design cross section geometry including soil and rock strata and the location, size and depth of the foundations. The design cross sections shall also include the critical slip surface shown where it will result in the minimum factor of safety.
3.Physical Properties of the Rock and Soil. The soil and rock shear strengths (friction angle and cohesion) and unit weights shall be shown for each soil and rock strat a. Geotechnical data is provided in the contract documents. Supplementary geotechnical data may be available and may be obtained from the Materials and Tests Engineer. Any additional subsurface information needed to design the aggregate foundations shall b e the responsibility of the Contractor.
4.Factors of Safety. The comparison of the calculated factors of safety and the minimum required factors of safety shall be shown for the design.
d.Minimum Requirements for the Submittal of Foundation Details.
1.Plan View of the Foundations. A drawing of the plan view of the aggregate foundations shall be submitted. The following details shall be shown on the plan view: - A reference baseline; - The offset from the construction centerline or baseline to the foundati ons; - Size and alignment of the foundations; - Right -of-way and permanent or temporary construction easements limits, location of all known active and abandoned existing utilities, adjacent structures and other potential interferences. - The centerline of any d rainage structure or drainage pipe behind, passing through, or passing under the foundations;
2.Elevation View of the Foundations. A drawing of the elevation view of the aggregate foundations shall be submitted. The following details shall be shown on the elevation view: - The elevation at the top and bottom of the foundations; - Size and alignment of the foundations; - Schematic and elevations of the structures supported by the foundations; - The centerline of any drainage structure or drainage pipe behind, passing through, or passing under the foundations.
e.Minimum Requirements for the Submittal of Construction Procedures. Construction procedures shall be submitted to identify all of the processes, equipment, tools and materials required for the construction and testing of the aggregate foundations. A quality control plan and examples of forms proposed for the documentation of construction daily progress reports and testing shall be submitted with the construction procedures.
573.05 Approved List of Aggregate Foundation Specialty Contractors.
The following aggregate foundation design -build specialty Contractors are approved to perform the work: • Geopier Rammed Aggregate Piers; Geopier Foundation Company; 150 Fairview Road, Suite 335; Mooresville, North Carolina 28117;
573.06 Construction Requirements.
• Vibro -Pier; Hayward Baker Corporation; 515 Nine North Court Alpharetta, GA 30004. Other aggregate foundatio n specialty Contractors will be given consideration for approval. Consideration for approval will be given to specialty Contractors that can provide documentation that they have successfully designed and constructed at least 3 projects in the last 3 years where the construction of permanent aggregate foundation totals at least 50 foundations.
573.06 Construction Requirements.
a.Compliance with the Submittal of Details and Construction Procedures. The foundation excavation, construction and testing shall be performed in accordance with the requirements shown on the submittal of foundations details and construction procedures distributed by the Engineer.
b.Daily Progress Reports. The Contractor shall furnish a complete and accurate record of aggregate fo undation installation to the Engineer. The record shall indicate the foundation location, length, drilled diameter, average lift thickness, and final elevations of the base and top of the foundations. The record shall also indicate the type and size of the densification equipment used. The Contractor shall immediately report any unusual conditions encountered during installation to the Engineer.
c.Excavation, Sheeting and Shoring. Excavation shall be extended if the Engineer determines that further excav ation is necessary for the removal of soft or yielding areas that may be uncovered. Sheeting and shoring may be required to protect the site of the excavation. Excavation will be paid for under other items of work (Section 210). Sheeting and shoring will also be paid for under other items of work (Section 215).
d.Construction Tolerances. Aggregate foundations shall be installed so that each completed foundation (column) will be continuous throughout its length. The center of the completed foundation ( column) shall be within 6 inches from the required horizontal location. The vertical alignment tolerance shall be a maximum of 2 inches horizontal for every 10 feet vertical of depth. The completed aggregate foundation diameter shall not be less than 10 p ercent smaller than the required diameter. The top of the ground improvement provided by the aggregate foundations shall be within 6 inches of the required elevation. Aggregate foundations shall be installed in a sequence that will minimize ground heave. Any heaving shall be re -compacted or excavated as directed by the Engineer prior to wall or embankment construction and be considered incidental to aggregate foundation construction.
e.Modulus Test. A modulus test shall be performed to verify the performance values selected for design. A telltale shall be installed at the bottom of a test foundation so that the deflection at the bottom of the column can be measured. The modulus test shall be conducted at a location where the bottom of the column termina tes in soil. Acceptable performance is when the deflection of the bottom of the foundation is no more than 20 % of the deflection at the top of the foundation at the design stress level. ASTM D -1143 general test procedures shall be used to establish load increments, load increment duration, and load decrements. With the exception of the load increment representing approximately 115 % of the design maximum foundation stress, all load increments shall be held for a minimum of 15 minutes, a maximum of 1 hour, and until the rate of deflection reduces to 0.01 inches per hour or less. The load increment that represents approximately 115 % of the design maximum stress on the foundation shall be held for a minimum of 15 minutes, a maximum of 4 hours and until the rate of deflection reduces to 0.01 inches per hour or less. A seating load equal to 5 % of the total load shall be applied to the loaded steel plate prior to application of load increments and prior to measurement of deflections to compensate for uneven surface conditions. The location of the modulus test will be determined by the Engineer.
f.Bottom Stabilization Verification Test. After completion of the construction of the bottom of the foundation, or at any time during the process of constructing the foundation a bottom stabilization verification test may be performed as required by the Engineer. These tests shall be performed when a new soil formation is encountered, at the beginning of a project to provide quantitative information o n foundation stabilization, and on 10 % of production foundations.
573.08 Basis of Payment.
Bottom stabilization tests shall be performed by placing a reference bar over the excavated cavity, marking the tamper shaft, applying energy to the tamper for an additional 15 seconds, and observing the downward deflection of the tamper shaft by observing the deflection of the mark on the tamper shaft. Acceptable performance is indicated if the movement of the shaft is less than 150 % of the vertical movement measured at the bottom of the foundation during the modulus test. If the measured vertical movement exceeds 150 % of the value measured during the modulus test, added energy shall be applied to further compact the aggregate. The procedure for measuring the movement shall then be repeat ed. If there is still movement greater than 150 % of that achieved during the modulus test and the movement is greater than 0.5 inches, a lift of loose aggregate may be placed on top of the compacted aggregate, and the verification test may be performed o n this next lift after it is densified. If there is excessive movement on this lift, another lift may be placed and tested. Movement must be limited to below 150 % of the movement determined from the modulus test before completion of 2/3 of the depth of the foundation.
573.07 Method of Measurement.
The Aggregate Foundations will be measured in units of cubic yards. The pay quantity for Aggregate Foundations shall be the volume calculated by multiplying the plan area of improvement by the average depth of the aggregate foundations installed during construction.
573.08 Basis of Payment.
a.Unit Price Coverage. The Aggregate Foundations will be paid for at the contract unit price. This payment shall be full compensation for all submittals, labor, equipment, tools, materials, material tests, field tests and incidentals necessary to acceptably construct the foundations.
b.Payment will be made under Item No.: 573-A Aggregate Foundations – per cubic yard
600.01 Description.
Division 600
INCIDENTALS SECTION 600 MOBILIZATION
600.01 Description.
This Section shall cover the preparatory work and operations including, but not limited to, those necessary for the movement of personnel, equipment, supplies, and incidentals to the pro ject site; for the establishment of all offices, buildings, and other facilities necessary for work on the project; and for all other work and operations which must be performed or costs incurred prior to beginning work on the various items on the project site. The lump sum bid for mobilization shall be so distributed among the various pay items of the contract that an overrun of a particular pay item will not adversely affect the unit price of that item.
600.02 Materials.
Not applicable.
600.03 Construction Details.
Not applicable.
600.04 Method of Measurement.
a.Partial Payment . Measurement of the item of Mobilization will be on a unit basis for each project or combination of projects included in a single contract. When more than one project is included in one contract, the amount of payment to be made will be based on the percent complete and amount of the entire contract, not the percent complete and amount of each individual project. Once the amount of payment is determined, based on the entir e contract, this amount will then be prepared for payment on each individual project based on the percentage of the total contract of which the project is a part. Partial Payments for mobilization are based on the amount bid for mobilization and the total original contract amount for all items of work. Payments will be made at the time, and in the amounts shown in the following schedules. SCHEDULE OF PARTIAL PAYMENTS FOR MOBILIZATION WHEN THE CONTRACT BID PRICE FOR MOBILIZATION IS LESS THAN, OR EQUAL TO 12 % OF THE ORIGINAL CONTRACT AMOUNT (Partial Payments are a % of the Contract Amount for Mobilization) TIME OF PAYMENT AMOUNT OF PAYMENT ACCUMULATED PAYMENT First Estimate 20 % of the Bid Price for Mobilization 20 % of the Bid Price for Mobilization After the First Estimate and Upon Completion of 5 % of the Original Contract Amount Excluding Prior Payment for Mobilization 50 % of the Bid Price for Mobilization 70 % of the Bid Price for Mobilization After the First Estimate and Upon Co mpletion of 50 % of the Original Contract Amount Including Prior Payment for Mobilization 30 % of the Bid Price for Mobilization 100 % of the Bid Price for Mobilization
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 465–468 of 934.