01032.03 Construction

All submittals shall be in electronic format.

A. CONSTRUCTION TOLERANCES.

1. The drilled shaft shall be within 3 inches (75 mm) of plan position at the top of shaft.

2. The vertical alignment of shaft excavation shall not vary from the plan alignment by more than 1/4 inch/foot (20 mm/m of depth).

3. Full depth reinforcing steel cages shall be set at no less than 6 inches (150 mm) above the bottom of the excavated shaft prior to placement of concrete.

4. After all the concrete is placed; the top of the reinforcing steel cage shall be no more than 6 inches (150 mm) above and no more than 2 3/4 inches (70 mm) below plan position.

5. The dimensions of casings are subject to American Pipe Institute tolerances applicable to regular steel pipe.

6. The top elevation of the shaft may have a tolerance of up to plus 1 inch (25 mm) or minus 3 inches (75 mm) from the plan top of shaft elevation. Sufficient reinforcement bar splice length for splices above the shaft shall be attained.

7. Excavation equipment and methods shall be designed so that the completed shaft excavation will have a planar bottom. The cutting edges of excavation equipment shall be normal to the vertical axis of the equipment within a tolerance of 3/8 inch/foot (30 mm/m) of diameter.

Drilled shaft excavations and completed shafts not constructed within the required tolerances are unacceptable. The Contractor shall be responsible for correcting all unacceptable shaft excavations and completed shafts to the satisfaction of the Engineer. Materials and work necessary, including engineering analysis and redesign, to complete corrections for out of tolerance drilled shaft excavations shall be furnished without either cost to the Contracting Authority or an extension of the completion dates of the project.

B. DRILLED SHAFT INSTALLATION PLAN
Two weeks prior to the pre-construction conference, the Contractor shall submit a list containing at least three projects completed in the last three years on which the Contractor has installed drilled shafts of a diameter and length similar to those shown on the plans.  The list of projects shall contain names and phone numbers of owner's representatives who can verify the Contractor's participation on those projects. The Contractor shall also submit a signed statement that they have inspected the project site and all the subsurface information made available in the contract documents.

No later than 1 month prior to constructing drilled shafts, the Contractor shall submit a drilled shaft installation plan for review by the Engineer. This plan shall provide information on the following:

1. Name and experience record of firm(s) and associated personnel for the following:

a. driller
b. drilled shaft superintendent
c. site exploration
d. confirmation boring
e. crosshole sonic logging (CSL)
f. name of load cell testing firm, if applicable

2. List of proposed equipment to be used including cranes, drills, augers, bailing buckets, grooving equipment, scouring equipment, final cleaning equipment, core sampling equipment, confirmation boring equipment, tremies or concrete pumps, casing, slurry equipment, airlift pumps, etc.

3. Details of overall construction operation sequence and the sequence of shaft construction in bents or groups.

4. Details of shaft excavation methods.

5. Details of casing and forms, including installation and removal.

6.  Details of the type and methods to mix, circulate, desand, test, and dispose of slurry (if applicable). If polymer slurry is proposed, submit data on load transfer and manufacturers requirements for slurry control.

7. Details of methods to clean the shaft excavation, including air lift methods and spin bucket methods as applicable.

8. Details of reinforcement placement including support and cage centering methods.

9. Reinforcing steel cage splicing method, if proposed, including details of dimensions, installation, splice location, support and cage centering methods, and estimated time required for splicing.

10. Details of concrete placement including procedures for tremie or pumping methods and method to prevent slurry intrusion at the discharge end.

11. Concrete mix proposal.

12. Details of methods to control cuttings, water, slurry, etc. with adjacent traffic conditions (vehicular or railroad if applicable).

13. Details of CSL testing including location and attachment methods of the steel access pipes.

14. When a load cell test is specified, details of the test equipment used in the load cell test, and description of load cell test procedures and program in accordance with Materials I.M. 388.

15. Details of methods used to groove the sides of the drilled shaft length within the bedrock supporting stratum and methods of scouring and verification of grooving.

16. Details of final discharge of concrete at top of shaft, of removing contaminated concrete, and verifying concrete uniformity for site specific conditions.

17. When casing is required, details on casing to be used, including specific length/depth of all casing proposed, and specific evaluation and determination of casing (size, depth, etc.) required to prevent any shaft installation procedure from having an effect or impact on adjacent structures, railroads, etc.

The Engineer will evaluate the drilled shaft installation plan for conformance with the contract documents. Within 14 calendar days after receipt of the plan, the Engineer will notify the Contractor of additional information required and/or changes necessary to meet the contract requirements.  All procedural approvals given by the Engineer shall be subject to trial in the field and shall not relieve the Contractor of the responsibility to satisfactorily complete the work as detailed in the contract documents.

A pre-drilling conference will be required for this work prior to the start of shaft excavation. The Contracting Authority, Contractor, and drilling staff shall discuss the anticipated shaft process.

C. CONTROL AND DISPOSAL OF MATERIALS
Disposal of excavated material, as well as slurry and/or water removed from the shaft excavation, shall be the responsibility of the Contractor. All slurry and water, displaced during final cleaning and concrete placement, shall be collected and properly disposed off site. Open pits for collection of materials will not be allowed. All excavated material, slurry, water, and other matter shall be controlled by the Contractor so that at no time it enters or encroaches upon the adjacent travel lanes, railroad, water ways, etc.

D. SHAFT EXCAVATION
The drilled shafts shall be constructed by either the wet, dry, or casing method as necessary to produce sound, durable concrete foundation shafts free of defects.

Surface and subsurface obstructions shall be removed by the Contractor. Special tools and/or procedures may be required. No separate payment will be made for removing obstructions.

The Contractor shall extend drilled shaft tip elevations if the Engineer determines that the material encountered during excavation and/or present at tip elevation is unsuitable and/or differs from that anticipated in the design of the drilled shaft.

The Contractor shall maintain a drilling log during shaft and socket excavation. The log shall contain information such as elevation, depth of penetration, drilling time in each of the strata, material description, and remarks. Two copies of the log, signed by the Contractor, shall be furnished to the Engineer within 1 week after completion of the excavation.

1. Wet Method
The wet method consists of keeping the shaft filled with slurry a minimum of 4 feet (1.3 m) above the highest expected water table during drilling and excavation, desanding of the slurry when required, final cleaning of the excavation by means of a bailing bucket, air lift, pump or other approved device and placing shaft concrete which displaces the slurry.

In the event that layers susceptible to cave-ins are encountered which cannot be controlled by slurry, the Contractor shall install temporary removable casing in accordance with Article 01032.03, D, 3.

2. Dry Method
The dry method shall be used only at sites where the ground water level and soil and rock conditions are suitable to permit construction of the shaft in a relatively dry excavation, and where the sides and bottom of the shaft can be visually inspected by the Engineer prior to placing the concrete. The dry method consists of drilling the shaft excavation, removing accumulated water and loose material from the excavation, placing the reinforcing cage, and concreting the shaft in a relatively dry excavation.

The dry method shall only be approved by the Engineer when the shaft excavation demonstrates that less than 12 inches (0.305 m) of water accumulates above the base over a 1 hour period when no pumping is permitted; the sides and bottom of the hole remain stable without detrimental caving, sloughing, or swelling between completion of excavation and concrete placement; and any loose material and water can be satisfactorily removed prior to inspection and concrete placement. Less than 3 inches (75 mm) of water will be permitted in the bottom of the shaft excavation at the time of concrete placement. The Contractor shall use the wet or casing method for shafts that do not meet the dry method requirements.

3. Casing Method
The casing method is used to advance the hole through unstable material. Over-reaming to the outside diameter of the casing may be required. Before the casing is to be removed, the level of fresh concrete shall be a minimum of 5 feet (1.5 m) above the bottom of the casing so that fluid trapped behind the casing is displaced upward. As the casing is withdrawn, the concrete level shall be maintained so that fluid trapped behind the casing is displaced upward without contamination or displacing shaft concrete.

The Contractor shall determine the appropriate depth where the temporary casing is terminated to ensure the stability of the shaft. The purpose of the temporary casing is to stabilize the shaft walls during drilling to prevent cave-ins as the result of potential vibrations. The purpose of the casing is also to prevent any shaft installation procedure from having an impact on adjacent structures, railroads, etc.

Permanent casing, if required, will be specified in the contract documents.

After the shaft excavation has been completed, the Contractor shall immediately proceed with shaft construction.

E. GROOVING SIDEWALLS
The sidewalls of the drilled shaft within the rock socket shall be grooved so as to produce channels with approximate dimensions of 2 inch (50 mm) depth by 3 inch (75 mm) height at intervals of 1 foot (0.3 m). Prior to grooving, excessive smearing of soft material that occurred on the rock socket wall shall be removed by a method approved by the Engineer and the base of the shaft shall be cleaned by spin bucket and air lift. Grooving shall be performed prior to final cleaning of the base of the shaft.

F. FINAL CLEANING
If a slurry cake builds up on the shaft sidewalls, the Contractor shall remove it prior to concrete placement at no additional cost. If mineral slurry is used, the shaft sidewalls above the rock socket shall be reamed prior to placement of reinforcement. The Contractor shall adjust operations so that the maximum time that the slurry is allowed to remain in the shaft is 24 hours.

The Contractor shall clean the base of each shaft so that a minimum of 50% of the base will have less than 1/2 inch (15mm) of sediment at the time of concrete placement. The maximum depth of sediment or debris at the base of the shaft shall not exceed 1 inch (25mm).

For dry shafts, visual inspection shall be performed by the Engineer.

For slurry shafts, the Contractor shall use an air lift to clean the bottom of the shaft.  After a wait period equal to the time to set the reinforcing steel cage and concrete placement setup, the Contractor shall measure the amount of sediment in the bottom of the shaft. If the amount of sediment meets the above requirements, the Contractor shall clean the base of the shaft a second time with the air lift and immediately proceed with shaft construction. If after the described wait period the amount of sediment exceeds the requirements, the Contractor shall clean the shaft by air lift and repeat the above procedure until the sediment accumulation meets the requirements. The Engineer may approve, at no additional cost to the Contracting Authority, an alternate method to clean the bottom of the shaft.

G. EXCAVATION INSPECTION.
The Contractor shall provide equipment for checking the dimensions and alignment of each shaft excavation. The dimensions and alignment of the shaft under construction shall be verified by the Contractor under the direction of the Engineer. Final shaft depths shall be measured with a suitable weighted tape or other approved methods after final cleaning.

H. REINFORCING STEEL CAGE CONSTRUCTION AND PLACEMENT.
The reinforcing steel cage consisting of longitudinal bars, ties, cage stiffener bars, spacers, cage centering devices, and other necessary appurtenances, shall be completely assembled and placed immediately after the shaft excavation is inspected and accepted, and prior to concrete placement. If approved by the Engineer, the reinforcing steel cage, as approximately two equal units, may be joined together in the shaft excavation after the first unit has been inserted.

The reinforcing steel in the shaft shall be tied and supported so that the reinforcing steel will remain within allowable tolerances given in these Supplemental Specifications.  Concrete spacers or other approved non-corrosive spacing devices shall be used at sufficient intervals, near the top and bottom and at intervals not exceeding 10 feet (3 m) along the shaft, to ensure concentric spacing for the entire cage length. Spacers shall be constructed of approved material equal in quality and durability to the concrete specified for the shaft.  The spacers shall be of adequate dimension to ensure a minimum distance of 3 inches (75 mm) between the cage and the excavated hole. When a full depth reinforcing steel cage is used, it shall be supported at the bottom by approved cylindrical feet to ensure that the bottom of the cage is maintained at the proper distance above the base. When a partial depth reinforcing steel cage is used, the Contractor shall design and furnish a support system.

The elevation of the top of the steel cage shall be checked before and after the concrete is placed. If the reinforcing cage is not maintained within the specified tolerances, corrections shall be made by the Contractor to the satisfaction of the Engineer. No additional shafts shall be constructed until the Contractor has modified the reinforcing cage support in a manner satisfactory to the Engineer.

I. CONCRETE PLACEMENT.
Shaft concrete shall be placed within 24 hours of the start of excavation of the rock socket.  Concrete shall be placed as soon as possible after reinforcing steel placement. The Contractor shall coordinate batching and delivery of the concrete with the batch plant so that the time limits, as stated in the Standard Specifications, between batching and delivery are not exceeded. Concrete placement shall be continuous. Concrete placement shall continue after the shaft excavation is full until good quality concrete is evident at the top of shaft. Remove a sufficient volume of concrete to ensure elimination of all contaminated concrete at the top of shaft before continuing with column construction. Concrete shall be placed either through a tremie or concrete pump.

1. Placement of Concrete by Tremie:
The tremie used to deposit concrete shall be constructed so that it is watertight and will readily discharge concrete. The tremie shall not be less than 10 inches (250 mm) in diameter, and there shall be no aluminum parts in contact with concrete.  The discharge end of the tremie shall be constructed to prevent water or slurry intrusion and permit the free flow of concrete during placement operations. The tremie shall have sufficient mass that it will rest on the shaft bottom before start of concrete placement. The length of the tremie shall be sufficient to extend to the bottom of the shaft. The discharge orifice shall be maintained between 5 feet and 10 feet (1.5 m and 3.0 m) below the surface of the fluid concrete. The tremie shall be supported so that it can be raised to increase the discharge of concrete and lowered to reduce the discharge of concrete. The flow of the concrete shall be continuous and the concrete in the tremie shall maintain a positive pressure differential at all times to prevent introduction of air pockets or contaminants into the concrete.

2. Placement of Concrete by Pump
Concrete pumps and lines may be used for concrete placement. All pump lines shall have a minimum 4 inch (100 mm) diameter and be constructed with watertight joints. Concrete placement shall not begin until the pump line discharge orifice is at the shaft base elevation.

A plug or similar device shall be used to separate the concrete from the fluid in the hole until pumping begins. The plug shall either be removed from the excavation or be of a material, approved by the Engineer, which will not be a detriment to the shaft if not removed.

The discharge orifice shall be maintained between 5 feet and 10 feet (1.5 m and 3.0 m) below the surface of the fluid concrete. When lifting the pump line during concreting, the Contractor shall temporarily reduce the line pressure until the orifice has been repositioned at a higher level in the excavation.

The pumping operation shall be performed in a manner that prevents introduction of air pockets into the concrete. If breaking of the pump line is required, the discharge orifice shall be temporarily positioned 3 feet to 5 feet (1.0 m to 1.5 m) below the surface of the fluid concrete in the hole. Additional methods to eliminate introduction of air into the concrete may be proposed by the Contractor.

The elapsed time from the beginning of concrete placement in the shaft to the completion of the placement shall not exceed 3 hours. All admixtures, when approved for use, shall be adjusted for the conditions encountered on the job so the concrete remains in a workable plastic state throughout the 3 hour placement limit. For construction of shafts larger than 6 feet (2 m) in diameter, the Contractor may propose placement time over 3 hours provided the Contractor submits trial mix documentation that all concrete in the shaft will retain a minimum 4 inch (100 mm) slump for the entire placement period.

All temporary casing shall be removed.

J. CROSSHOLE SONIC LOG (CSL) TESTING.
The Contractor shall coordinate with an independent testing agency to perform CSL testing in accordance with ASTM D 6760; and provide analysis and interpretation on each completed shaft.

The procedure in ASTM D 6760 will be followed with the following exceptions:

1. Plastic access ducts and drilled boreholes will not be allowed unless approved by the Engineer.

2. A minimum of 4 access ducts are required.

3. The Crosshole Sonic Log (CSL) testing shall be performed after the shaft concrete has cured at least 48 hours but no later than 7 calendar days.

4. The access ducts shall be grouted after approval of the testing results by the Engineer.

5. The waterfall diagram (which is a nesting of ultrasonic pulses in an ultrasonic profile) shall be included in the report.

The Contractor shall furnish and install one access pipe per 1 foot (0.3 m) of shaft diameter but no less than four per shaft, with external couplings for CSL testing. The access pipes shall be 2 inch (51 mm) diameter, Schedule 40 pipe conforming to ASTM A 53, Grade A or B, Type E, F, or S.  The access pipes shall have a round, regular inside diameter free of defects and obstructions, including all pipe joints, in order to permit the unobstructed passage of 1 3/8 inch (35 mm) maximum diameter source and receiver probes used for the CSL tests. The access pipes shall be watertight and free from corrosion with clean internal and external faces to ensure a good bond between the concrete and the access pipes. The access pipes shall be fitted with a watertight cap on the bottom and a removable, watertight cap on the top to prevent debris from entering the pipes. Any joints required to achieve the specified length shall also be watertight.

The Contractor shall securely attach the access pipes to the interior of the reinforcing cage such that each pipe is equally spaced within the reinforcing cage. If a partial depth reinforcing cage is specified, the Contractor shall design and furnish a support system to secure and properly align the CSL access pipes.

The access pipes shall be installed in straight alignment and parallel to the vertical axis of the reinforcing cage. The access pipes shall extend to the bottom of the shaft or to the top plate of a load cell placed at the bottom of the shaft. When a load cell is located above the bottom of the shaft, the access pipes shall be fitted with watertight slip joints between the load cell bearing plates. The access pipe shall extend at least 2 feet (600 mm) above either the top of the continuous concrete placement operation or the top of the shaft. Care shall be taken to prevent damaging the access pipes during the reinforcing steel cage installation.

The access pipes shall be filled with clean water prior to concrete placement. Each access pipe shall be resealed immediately after water placement to prevent debris from entering the pipe. The Contractor, prior to CSL testing, shall flush any access pipes containing debris, refill with water of similar temperature, and reseal. Water of similar temperature shall be used to avoid debonding of access pipes with surrounding concrete.  All access pipes shall be dewatered and filled with grout after the tests are completed, and the shaft has been accepted by the Engineer. The grout shall meet the requirements of Materials I.M. 388.

The test results, analysis, and interpretation submittal for the shafts shall be provided to the Engineer by the Contractor within 7 calendar days of testing. The Engineer will determine final acceptance of each shaft, based on the CSL test results and analysis for the tested shafts, and will provide a response to the Contractor within 5 working days after receiving the test results and analysis submittal.

The Contractor shall not commence subsequent shaft excavations until receiving the Engineer’s approval and acceptance of the first shaft; based on the results, analysis, and interpretation of the CSL testing for the first shaft.

The Contractor shall not commence subsequent construction of the structure until receiving the Engineer’s approval and acceptance of the supporting shaft; based on the results, analysis, and interpretation of the CSL testing for the supporting shaft.

For all shafts determined to be unacceptable, the Contractor shall submit a plan for remedial action to the Engineer for approval. All remedial correction procedures and designs shall be submitted to the Engineer for approval. The Contractor shall not begin repair operations until receiving the Engineer’s approval of the remedial action plan.

K. DEMONSTRATION SHAFT
The Contractor shall demonstrate equipment and methods, prior to construction of the first production drilled shaft by installing a non-production drilled shaft. This shaft shall be installed on site at a location to be determined by the Engineer.

The demonstration shaft shall be constructed a minimum of 3 feet (1 m) into bedrock and will require a reinforcing steel cage, designed by the Contractor, to adequately support the CSL tubes. The demonstration shaft shall be constructed in accordance with the requirements of these Supplemental Specifications with special emphasis on slurry control and disposal, method of scouring, air lift pump usage, concrete delivery and coordination with the batch plant, concrete slump at the point of delivery, concrete placement, and shall include one break of the concrete pump line.

If installation of the demonstration shaft does not demonstrate the adequacy of the Contractor’s equipment and methods to construct drilled shafts to the requirements of these Supplemental Specifications, the Engineer will require the Contractor to make appropriate alterations in equipment and/or methods to eliminate the unsatisfactory results. The Contractor may be required to perform additional demonstration shafts until an adequate procedure is demonstrated and approved by the Engineer. Construction of production drilled shafts shall not begin until the Engineer approves of Contractor’s methodology and reviews the CSL report. The Engineer will complete the review process within 5 working days.

If the Contractor has demonstrated sufficient experience in the construction of drilled shaft foundations in soil/rock and under conditions similar to those at this site, and if other applicable factors indicate it to be acceptable, the “Demonstration Shaft” item will be deleted from the contract.

L. TEST SHAFT
When required in the contract documents, a test shaft shall be installed at the location indicated in the plans. The final selected depth of the test shaft shall be based on the confirmation boring.

1. Confirmation Boring and Sampling.
Prior to installation of the test shaft, a confirmation boring shall be completed by the Contractor at the test shaft location to a depth 10 feet (3 m) below the bottom elevation as shown in the plans or a minimum of 30 feet (10 m) into the bedrock, whichever is greater.

Standard penetration tests shall be performed in accordance with ASTM D 1586 in the soil overlying bedrock. Standard penetration tests shall be performed on 5 foot (1.5 m) centers. Moisture contents shall be determined on the soil samples.  The soil sampling and testing shall continue with split barrel (spoon) sampling, in accordance with ASTM D 1586, until the top of bedrock is encountered. Rock shall be cored using double barrel diamond coring methods producing a minimum 1.75 inches (44.4 mm) core in accordance with ASTM D 2113, or other approved sampling method. Records shall be kept, including Percent Core Recovery and Rock Quality Designation in accordance with ASTM D 2113 and D 6032. Rock samples shall be preserved at their natural moisture content and condition, and transported to the laboratory for classification by a Professional Engineer licensed in the State of Iowa.

Representative samples of intact rock shall be tested for unconfined compressive strength in accordance with ASTM D 2938 except that stress and strain shall be recorded in accordance with ASTM D 2166, up to 20% strain or failure, whichever occurs first. A stress-strain plot shall be prepared in addition to listing of the unconfined compressive strength. One unconfined compression test will be performed for every 3 feet (1.0 m) of rock core. Testing and coring shall be performed by the Contractor’s geotechnical drilling and testing firm. Test samples will be selected by the Engineer. Installation of the test shaft shall not begin until the results of the confirmation boring have been submitted and reviewed, and incorporated in the proposed load test program to be submitted in accordance with Materials I.M. 388. The Engineer will complete the review of the confirmation boring report and the proposed load test program report within 7 calendar days after submittal.

2. Load Cell Test
When required by the contract documents, the Contractor shall furnish all materials and labor necessary to conduct a load cell test in accordance with Materials I.M. 388.

Telltale casings shall be installed to allow measurement of shaft movement during load cell testing.

The Contractor shall use the utmost care in handling the rebar cage/test equipment assembly so as not to damage the load cell and instrumentation during installation.

After the CSL test has been approved and the concrete has reached a minimum required strength of 3500 psi (24 MPa), the load cell shall be internally pressurized, creating an upward force on the shaft and an equal, but downward force. The total load for a given internal pressure is found from the load cell’s calibration, which shall be performed prior to its shipment to the site. During the period required to perform the load test, no casings may be vibrated into place or steel piles installed within 200 feet (60 m) of the load test.

If the test shaft is a production shaft, the load/deflection curve shall be monitored and testing shall be stopped so that the capacity of the shaft is not compromised. The load cell shall then be unloaded and reloaded to verify that the test shaft has at least the design capacity. If the test shaft is not a production shaft, the load cell test shall be continued until ultimate capacity is reached or the capacity of the load cell is reached.

If the test shaft is a production shaft, the hydraulic lines and load cell cavities shall be grouted upon completion of the load cell test. The grout shall meet the requirements of Materials I.M. 388.

The Contractor shall supply 4 printed copies and 1 electronic copy of the report for each load test, as prepared by the approved firm in Materials I.M. 388 within 14 calendar days of the test completion. Field results shall be provided upon completion of the test. The report shall include, but not be limited to, the following:

a.  Load distributions, skin friction, and end bearing for the various strata instrumented by the strain gauges.

b. Summary of drilled shaft’s dimensions, elevations, areas, and masses. Boring logs, test data, and other relevant information from the confirmation boring.  Log of the Contractor’s installation along with actual mapping of the shaft profile.

c. Load movement for end bearing and upward shear.

d. Equivalent top load movement curve.

e. Side shear creep limit curve.

f. End bearing creep limit curve.

g. Side shear load transfer for each zone/layer identified in the confirmation boring report, where strain gauges were installed, or as modified by the Engineer and the approved firm in Materials I.M. 388.

h. Plots of mobilized side shear load transfer versus vertical displacement for each zone/layer identified in the confirmation boring report, where strain gauges were installed.  Layers may be modified in final load test design, if approved of by the Engineer.

i. Tables with test data.

If the test shaft is determined to be unacceptable by the Engineer, the Contractor shall submit a plan for remedial action to the Engineer for approval and the Engineer may require another load cell test on another shaft. Construction of the production shafts shall not begin until Engineer approves of Contractor’s methodology, reviews CSL report and reviews load cell test results. Prior to commencement of the load cell test, any cavities or inclusions shall be repaired and the repairs shall be approved by the Engineer. The Engineer will complete the review process within 14 calendar days of the load test report submittal.  The load test results will be used to evaluate the shaft capacities within the bedrock and to define the final bottom elevation of the remaining productions shafts. The final bottom elevation of the remaining production shafts may vary from what is shown on the plans.

Once the load cell test has been completed and approved by the Engineer, the Contractor shall clean up the test shaft site. If the test shaft is a production shaft, site cleanup shall include whatever measures are required to incorporate the test shaft into the foundation, subject to approval by the Engineer. If the test shaft is not a production shaft, the test shaft shall be removed 3 feet (1 m) below final ground level and the area cleared in accordance with Article 1104.08 of the Standard Specifications.

01032.04 METHOD OF MEASUREMENT.

A. Concrete Drilled Shaft
The Engineer will measure in feet (meters), to the nearest 6 inches (0.15 m), the length of Concrete Drilled Shafts constructed.

B. Reinforcing Steel
Reinforcing Steel will be measured in accordance with Section 2404 of the Standard Specifications.

C. Load Cell Test
The Engineer will count the number of load cell tests.

D. Demonstration Shaft
The Engineer will measure in feet (meters), to the nearest 6 inches (0.15 m), the length of the approved Demonstration Shaft constructed.

01032.05 BASIS OF PAYMENT