Section 02373 DRILLED PIERS

Section 02373

DRILLED PIERS

PART 1 - GENERAL

_{1.1 SCOPE}

A. This Specification covers requirements for drilled pier construction and applies to drilled piers of 30 in. diameter. The CONTRACTOR shall submit proposed installation methods to the ENGINEER. Methods compatible with the design intent, as determined by ENGINEER, will be accepted. Methods that are not compatible with the design intent will be rejected.

1.2 RELATED WORK SPECIFIED ELSEWHERE

A. The requirements of the following Specification sections and divisions apply to the Work of this section. Other sections and divisions of the Specifications, not referenced below, shall also apply to the extent required for proper performance of this Work.

1. Section 03100, Concrete Formwork

2. Section 03200 Reinforcement Steel

3. Section 03290, Joints in Concrete

4. Section 03300, Cast-in-Place Concrete

5. Section 03350 Concrete Testing

6. Section 07130, Concrete Sealer and Hardener

7. Section 07900, Joint Sealants

1.3 DEFINITIONS

A. The following definitions cover the meanings of certain words and terms used in this

Specification.

1. Anchorage Embedment: Embedment of the anchorage system, such as anchor bolts or threaded rods, used to fasten structural components to the piers.

2. Bearing Stratum: The soil or rock stratum that carries the load transferred to it by a drilled pier.

3. Casing: A permanent or temporary steel cylinder used to resist earth and water pressures, to serve as a concrete form, and to protect personnel.

4. Centralizer: A device to keep the reinforcement cage the required distance away from the sidewall.

5. Controlled Slurry: Slurry that is controlled to conform to specified properties.

6. Cut-Off: The top of concrete at a pier, a level surface at the elevation shown on the Drawings.

7. Drilled Pier: A foundation element extended downward by drilling through earth materials, water, or both, to an acceptable design depth and filled with structural reinforced concrete.

8. Dry Method: Method of pier installation in which concrete is placed in the dry and where casing may be used to maintain sidewall stability.

9. End Bearing: Where load is supported at the bottom of the pier.

10. Liner: A cylindrical form of pier design diameter having the tensile strength to withstand internal concrete pressures and not designed for external earth and water pressures; used inside an oversized temporary casing to prevent possible concrete contamination when temporary casing is removed.

11. Pig: Device inserted into a tremie or pump pipe to separate the concrete from the pier excavation fluid inside the pipe.

12. Probe Hole: A 1.6- to 2.5-inch diameter hole usually drilled by air percussion methods to a required depth below the pier bottom. The inspector feels the probe hole wall by lowering and raising a hooked rod. The size and amount of seams found enables the determination of the soundness of the soil formation.

13. Side-Resistance: Friction developed along the side of a drilled pier that transmits vertical forces to the surrounding soil or rock.

14. Slurry Displacement Method: Method of drilling, concreting, or drilling and concreting in which controlled slurry consisting of water, with or without additives such as bentonite, attapulgite, or polymer, is used to stabilize the hole; the slurry may be used to maintain the stability of the uncased drilled pier hole to allow concrete placement when water seepage into a drilled pier hole is too severe to permit concreting in the dry, or both.

15. Tremie Method: Procedure for placing concrete underwater or slurry using a watertight steel pipe or tube to place concrete without washing out cement fines.

1.4 REFERENCE STANDARDS

A. General-Standards of ACI, ASTM, AWS, and API referred to in this Specification are listed with their serial designation, including year of adoption or revision, and are part of this Specification.

1.	ACI Standards: ACI 117-90	Standard Specifications for Tolerances for
		Concrete Construction and Materials
	ACI 301-99	Specifications for Structural Concrete
2.	ASTM Standards:
	A 36/A 36M-97a	Specification for Carbon Structural Steel
	A 283/A 283M-97	Specification for Low and Interme-diate Strength Carbon Steel Plates
	A 615/A 615M-96a	Specification for Deformed and Plain Billet-Steel Bars for Concrete Reinforcement
	A 616/A 616M-96a	Specification for Rail-Steel Deformed and Plain Bars for Concrete Reinforcement
	A 617/A 617M-96a	Specification for Axle-Steel Deformed and Plain Bars for Concrete Reinforcement
	A 706/A 706M-96b	Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete Reinforcement
	A 929/A 929M-97	Specification for Steel Sheet, Metallic Coated by the Hot-Dip Process for Corrugated Steel Pipe
	C 31/C 31M-OO	Standard Practice for Making and Curing Concrete Test Specimens in the Field

C 39-96 Test Method for Compressive Strength of

Cylindrical Concrete Specimens

C 94/C 94M-98c Specification for Ready-Mixed Concrete

C 143/C 143M-98 Test Method for Slump of Hydraulic Cement

Concrete

C 150-98 Specification for Portland Cement

C 494-98a Specification for Chemical Admixtures for

Concrete

C 1017/C 1017M-98 Specification for Chemical Admixtures for Use in

Producing Flowing Concrete

C 1064-86 Test Method for Temperature of (Revised 1993) Freshly Mixed Portland Cement Concrete

D 4380-84 Test Method for Density of Bentonite Slurries

(Revised 1993)

D 4381-84 Test Method for Sand Content by Volume of

Bentonite

(Revised 1993) Slurries

D 4972-95a Text Method for pH of soils

3. API Standards:

RP13 B-1(1990) Standard Procedures for Field Test-ing Water- Based Drilling Fluids

4. AWS standards

D1.1-96 Structural Welding Code-Steel

D1.4-92 Structural Welding Code-Reinforcing Steel

1.5 STANDARDS-PRODUCING ORGANIZATIONS

A. Abbreviations for and complete names and addresses of organizations issuing documents referred to in this Specification are listed:

American Concrete Institute (ACI) P.O. Box 9094

Farmington Hills, Mich. 48333-9094

American Petroleum Institute (API) Production Department

211 N. Ervay, Suite 1700

Dallas, Tex. 75201

American Society for Testing and Materials (ASTM)

100 Barr Harbor Drive

West Conshohocken, Pa. 19428

American Welding Society (AWS)

550 NW LeJeune Road

Miami, Fla. 33126

1.6 STANDARD UNITS

A. The values stated in inch-pound units are to be regarded as the standard.

1.7 PROJECT CONDITIONS

A. The CONTRACTOR shall perform the following activities:

1. Examination of Site: Determine any constraints to the Work presented by the existing surface conditions and report them to ENGINEER.

2. Subsurface Data: Review the subsurface investigation results. Discover and document any substantial difference between actual subsurface conditions and those reported. Notify ENGINEER in writing within 48 hours of such discovery.

3. Existing Underground Utilities: Locate in the field all existing underground structures and utilities. Determine if there are conflicts with the Work. Report any conflicts to ENGINEER. Cease work in this area until the conflicts are resolved.

1.8 QUALITY ASSURANCE A. ENGINEER:

1. ENGINEER will provide inspection of the drilled-pier construction. This Specification provides that construction engineering decisions will be made by ENGINEER during the course of the Work as unknown or unforeseen conditions are encountered. At the completion of the Work, ENGINEER will determine the acceptability of the pier installation within the terms and conditions of the Contract Documents and his or her construction engineering decisions.

B. CONTRACTOR:

1. The CONTRACTOR shall:

a. Provide site supervisor and drillers, each with a minimum of 3 years of acceptable experience in installing similar types of drilled piers. If an installation method is specified, experience with this method is required;

b. Schedule and provide time and means for ENGINEER to inspect each drilled pier before concreting;

c. Provide the Testing Agency the means and opportunity to take samples and make tests;

d. Submit a program to OCSD for quality control;

e. Submit a detailed description of field procedures for pier construction, whether a wet or dry method is to be used, including procedures for excavation, dewatering, slurry type, and source and casing withdrawal, if applicable; and

f. Perform all excavation or concrete Work in the presence of ENGINEER.

g. Testing procedures and frequency shall be as described in section 03350, Concrete Testing.

C. Testing Agency:

1. The Testing Agency will perform required tests on construction materials to check conformance with the Contract Documents. Required tests on concrete include slump and temperature on site in accordance with ASTM C 143/C 143M and ASTM C 1064, and compressive strength of standard-cured cylinders prepared in accordance with ASTM C 31/C 31M and tested in accordance with ASTM C 39. CONTRACTOR to pay for all tests required for this section’s related Work.

1.9 SUBMITTALS BY THE CONTRACTOR

A. Submit to ENGINEER before starting the Work:

1. Experience record of supervisory personnel and drillers.

2. List of equipment and equipment operating procedures.

3. Shop drawings showing location and size of reinforcing steel.

4. A Pile Layout Plan and a Table to be used and annotated in the field which is referenced to the Drawings, including a numbering system capable of identifying each individual pile. The pile layout plan shall include the horizontal coordinates of each pile, the design tip elevation and design cutoff elevation. Additional columns in the Table to be usedfor annotations in the field shall include Actual reinforcing splice location(s); Final tip elevation; Remarks column for documenting such occurrences as relocations due to striking obstacles, whether slurry was needed, if water was struck, if casing was used and to what depth, whether casing was left in place and any other occurrences of note during the construction of the piers. This Table shall be made maintained by the CONTRACTOR and shall be delivered to the ENGINEER for use in preparing Record Drawings at the end of the Project.

5. Proposed concrete materials and mixture proportions conforming to the requirements of ACI 301.

6. Detailed field procedures for pier construction, including excavation, concreting, and casing withdrawal, if applicable. Include proposed method for assuring the proper placement of the reinforcing including clearances and monitoring of concrete to assure no concrete occur.

7. If spoil, drilling fluid, or both are to be disposed of off site, submit letters of approval from all governmental agencies with jurisdiction over proposed disposal sites.

8. Welding procedures for permanent casing.

9. AWS welder certification for permanent casing.

10. Welding procedures for reinforcement.

11. AWS welder certification for reinforcement.

12. Quality control program.

13. Test report from the supplier giving the slurry type and admixtures and the physical and chemical properties of the mixed slurry.

14. Size, wall thickness, type of steel, and length of permanent and temporary steel casing.

15. Size, length, material, and strength of liner.

16. Any splice requirements other than those in the Contract Documents. B. Submit the following to ENGINEER during construction:

1. Notification to ENGINEER in time to permit in-place inspection of the completed excavation before placement of reinforcing steel and before placing concrete.

2. Reports of material quantities such as concrete, reinforcement, and slurry.

3. Certified mill test reports for reinforcing steel, including bar markings.

4. Reports of in-hole slurry tests during construction in accordance with Article 3.5.

5. Concrete batch-plant tickets containing the information required by ASTM C 94.

6. Reports of as-built location, alignment, elevations, and dimensions of drilled piers, specifically identifying those piers that are not in accordance with the Contract Documents.

7. Graphical plot of theoretical concrete volume and actual measured volume versus depth or elevation for each drilled pier constructed by the slurry displacement method.

PART 2 - PRODUCTS

2.1 GENERAL

A. This section covers requirements for materials and products in connection with construction of drilled piers.

2.2 STEEL CASING AND LINER

A. Steel casing liner shall conform to the requirements of ASTM A 283, Grade C; ASTM A 36; or ASTM A 929.

B. Full-penetration welds shall meet AWS D1.1 requirements for joints in non- corrugated permanent casings and be welded by AWS-certified welders. Welding procedures and welder certifications shall be submitted to ENGINEER for acceptance.

C. Casing shall be of sufficient strength to withstand handling stresses, drilling stresses, concrete pressures, and surrounding earth and water pressures, to protect personnel as required, and to permit advancement of the pier through caving ground. Size and length of casing shall be submitted to ENGINEER for acceptance.

D. Liner shall be of sufficient strength to withstand internal concrete pressures. Size, length, material type, and strength of liner shall be submitted to ENGINEER for acceptance.

2.3 REINFORCING STEEL

A. Reinforcing steel shall conform to ASTM A 615, A 616, A 617, or A 706. ASTM A 616 bars (rail steel) shall meet the bend-test requirements of axle-steel reinforcing bars, ASTM A 617, Grade 60, and the bar markings rolled into the surface of the bars shall include the letter "R" to designate rail steel. Bars to be welded shall conform to ASTM A

706. Shop drawings and mill test reports on reinforcing steel shall be submitted. Welding procedures shall be submitted, if applicable.

B. Reinforcement shall be spliced in conformance with the Contract Documents.

2.4 CONCRETE

A. Concrete and concrete Work shall conform to ACI 301. Concrete materials and mixture proportion information shall be submitted in accordance with ACI 301.

B. Concrete of the specified slump and strength shall be provided and placed. Concrete for use in the slurry displacement method (Article 3.5) shall have a maximum nominal aggregate size of 3/4 inch.

C. Concrete shall meet the slump requirements given in Table A until placement is complete.

_{Table A. Concrete slump requirements during placement}

Slump (inch)	Drill Method
4 to 6	Dry, uncased, or permanent casing
6 to 8	T emporary casing
7 to 9	Slurry displacement

D. Water-reducing, set-retarding admixtures shall conform to ASTM C 494, Type D, to meet slump requirements and to delay concrete setting.

E. High-range, water-reducing, and set-retarding admixtures shall conform to ASTM C

494, Type G or ASTM C 1017, Type II only with the acceptance of ENGINEER. F. Cement shall conform to ASTM C 150 Type V.

G. Calcium chloride or any admixture containing chloride ions shall not be used.

2.5 SAND-CEMENT GROUT

^{A. Sand-cement grout suitable to fill annular void outside pe})^{rmanent casing or} permanent liner shall be provided and placed in a manner acceptable to ENGINEER. The mixture shall consist of a minimum of 188 lb/yd3 (112 kg/m3 of Type V cement, an acceptable sand, and shall have a water-cementitious materials ratio (w/cm) less than

1.0.

2.6 CONTROLLED SLURRY

A. Slurry shall consist of a stable colloidal suspension of various pulverized clays or polymers thoroughly mixed with water and having the properties given in Table B or as accepted by ENGINEER.

B. Water used to mix slurry shall be obtained from sources accepted by ENGINEER.

_{Table B. Required Slurry Properties}

Item to be Measured	Range of Results at 68 F	Test Methods
I. Density before concreting lb/ft3 (kg/m3 for slurry) 1 ft from pier bottom		(Mud balance) ASTMD4380
a. Mineral slurries (bentonite/81top•dgilc)
I. No end bearing	85 max
2. With end bearing	70 max
b. Polymer slurry
I. No end bearing	64 max
2. With end bearing	64 max
2. Marsh funnel viscosity for entry, s.lqt (s/L)		(Marsh funnel) API- RPI3B- Section 2
a. Bentonite/attapulgite	26 to 50
b. Polymer slurry	40 to 90
3. Sand content in slurry, immediately before concreting, 1 ft from bottom, by volume,%		(Sand screen set) ASTMD4381
a. Mineral slurries (bentonite/attapulgite)
I. With end bearing	4 max
2. No end bearing	20 max
b. Polymer slurry
I. With end bearing	1 max
2. No end bearing	1 max
4. pH during excavation	7 to 12	ASTMD4972

*Or as recommended by manufacturer and accepted by ENGINEER.

PART 3 - EXECUTION

3.1 TOLERANCES

A. Tolerances shall be in accordance with ACI 117, except as follows:

1. General:

a. Location tolerance at cut-off shall be no greater than 1/24 of the specified shaft diameter or 3 inches, whichever is greater. If the as-installed shaft is larger than specified, the center of the shaft may be taken as the center of a circle having the specified area that lies within the as-installed shaft.

b. Out-of-plumbness of piers shall not exceed 1.5 percent.

2. Bottom area:

a. Provide bottom area not less than that shown on the Drawings, or as acceptable to ENGINEER.

3. Bottom slope:

a. Excavate the bottom of the pier to a level plane within a tolerance of 1 vertical to 12 horizontal, or as acceptable to ENGINEER.

4. Pier shaft diameter:

a. Provide pier shaft diameter shown on the Drawings, or as accepted by

ENGINEER. Maximum diameter shall be as accepted by ENGINEER.

5. Anchorage embedment tolerance:

a. Limit the vertical and horizontal deviations of individual anchorage components from the specified location to plus or minus 0.5 inch.

3.2 DRY METHOD

A. Excavate drilled piers to dimensions and required elevations shown on the Drawings. Clear all obstructions encountered during excavation.

B. Maintain sidewall stability during drilling and extend excavation to the stratum specified by ENGINEER.

C. ENGINEER will determine actual final bearing levels during excavation based on suitability of bearing stratum.

1. For end-bearing piers, explore bearing stratum with a probe hole to a minimum depth equal to the diameter of the bearing area below the bottom of each drilled pier, unless otherwise directed by ENGINEER.

2. Provide a safe method for personnel access to inspect the bottom of the drilled pier. Alternatives to direct downhole inspection shall be approved by ENGINEER.

D. Check each drilled pier for toxic and explosive gas before inspection of drilled hole. If gas is found, ventilate with forced air until safe for inspection, or follow alternative procedures acceptable to ENGINEER. During operations necessitating entry into the shaft, provide gas-testing equipment and a protective cage, or temporary casing of proper diameter, length, and thickness, plus other safety equipment called for by Federal, State, and local laws for inspection and testing of drilled piers and protection of workers.

E. Remove loose material and free water from bottom of drilled piers, unless otherwise directed by ENGINEER. If the bottom is sloping rock, excavate to either a level plane or step the bottom with one step whose rise is less than 1/4 the diameter of the bearing area.

F. Excavate rock sockets as specified by the Contract Documents. Provide the socket roughness specified. Drill a probe hole to a maximum depth of one pier diameter, unless otherwise directed by ENGINEER.

G. Keep all excavated materials an acceptable distance away from each open pier excavation.

3.3 STEEL CASING AND LINER

A. Delivery, handling, and storage of casing:

1. Deliver casing to the site in an undamaged condition.

2. Handle and protect casing to maintain diameter within plus or minus 2 percent of the specified diameter.

B. Casing shall be continuously joined and have the strength and rigidity needed to maintain the required excavation dimensions against earth, drilling, and water pressures. If an inner permanent liner is used to permit casing withdrawal, it shall have the strength and rigidity to contain the concrete during placement.

1. Provide steel casing for shaft excavation where required. Make diameter of excavation such that the void space outside any temporary casing is minimized.

2. Withdrawal of temporary casing is at the CONTRACTOR's option, provided no anomalies in shaft placement occurred.

3.4 REINFORCING STEEL

A. Reinforce drilled piers as specified in the Contract Documents.

B. Place reinforcement for drilled piers, as shown on the Contract Documents, after acceptance of the drilled pier excavation.

C. Reinforcement shall be free of mud, oil, other surface contamination, and excessive corrosion at time of concrete placement, in accordance with ACI 301.

D. The sizes and configuration of vertical reinforcing and tie steel shall be as shown on the Drawings. Maintain proper dimension and location of reinforcing steel during concreting operations.

E. Straighten or repair bars with kinks or unspecified bends in a manner acceptable to

ENGINEER that will not damage the bars and will maintain the required cover.

F. Reinforcement cover shall be not less than 3 inches where exposed to soil and not less than 4 inches in cased piers where the casing is to be withdrawn.

1. The reinforcing cage shall be tied and supported in the shaft so the cage will remain within specified tolerances.

2. Provide centralizers to maintain cover.

a. Centralizers shall be plastic wheeled spacers acceptable to ENGINEER.

b. Centralizers shall be used at intervals not exceeding five feet along the length of the shaft. Start placing centralizers at the bottom of the cage. Each level of centralizers shall be rotated 45 degrees in the horizontal plane relative to the level below.

G. Splice vertical reinforcing steel in accordance with ACI 318 for compression or tension. Submit splice details. Stagger splice locations one lap length on alternating bars.

H. Weld reinforcing bars in accordance with AWS D1.4. Use AWS-certified welders.

I. The minimum clear distances between reinforcement, including lapped bars, shall be

4 inches or four times the maximum aggregate size, whichever is larger.

J. Place reinforcement before pier concreting begins, unless otherwise allowed by

ENGINEER.

K. Limit reinforcing-steel vertical movement during casing withdrawal to 6 inches.

3.5 SLURRY DISPLACEMENT METHOD A. General:

1. This section covers the special requirements for the slurry displacement method of installation. Materials and execution related to steel casing, reinforcing steel, and concrete shall be in accordance with Articles 3.2, 3.3, and 3.4, respectively, except as noted. The installation and slurry materials shall be in accordance with this Section.

B. Installation Procedure:

1. Use slurry, unless the water, in combination with colloidal fines from soil being excavated, stabilizes the hole and is acceptable to ENGINEER.

2. Obtain slurry from sources acceptable to ENGINEER. Mix, store, and transport slurry using equipment made for these purposes.

3. Submit plans and test results for any physical or chemical treatment of the water or slurry necessary to meet the requirements of Table B that are acceptable to ENGINEER.

4. Set temporary surface casing to contain the slurry, unless otherwise specified by

ENGINEER.

5. Use slurry to stabilize the excavation. Where drilled piers are installed below groundwater or in caving soils, maintain the slurry level in the excavation not less than 5 ft above the groundwater level to provide a stable hole. Maintain the slurry level above any unstable zones a sufficient distance to prevent caving or sloughing of those zones. Demonstrate to the satisfaction of ENGINEER that stable conditions are being maintained.

6. The in-hole slurry shall meet the specified properties, as given in Table B, before concreting. Recycling of slurry is permitted provided that the recycled slurry satisfies the Table B requirements. Clean, recirculate, remove sand from, or replace the slurry to maintain the required slurry properties. Submit to ENGINEER a written record of results for the Table B tests for each drilled pier installed.

7. Complete concreting the drilled pier the same day that the excavation is completed. If this is not possible, redrill, clean, and test the slurry in the excavation before concreting.

C. Excavation:

1. Use excavation methods that leave the sides and bottom of the hole free of loose material that would prevent intimate contact of the concrete with firm, undisturbed soil or rock. If loose or unacceptable material is present, reclean the hole to the satisfaction of ENGINEER.

2. For piers designed without end bearing, the accumulated sediment at the bottom of the pier, measured just before concreting, shall be less than 6 inches. If greater, reclean the hole.

3. Remove all soil and excavated materials and store them a sufficient distance from each open pier excavation to avoid contamination of the excavation after final clean out.

4. Use drilling tools and excavation procedures that minimize negative pressure and avoid disturbance of the surrounding material in the excavation. Raise and lower the drilling tool in the hole at a rate that does not swirl the slurry and affect the stability of the hole.

5. At the completion of excavation and also before the start of concrete placement, clean the drilled-pier bottom with an air-lift, recirculation system, or a cleanout bucket equipped with a one-way flap gate that prevents soil in the bucket from reentering the pier.

D. Concrete and Reinforcing Steel:

1. Place reinforcing steel in accordance with the Contract Documents.

2. Use concrete in the slurry displacement method that satisfies the requirements of

Article 2.4.

3. Do not start concrete placement until a concrete supply adequate to fill the pier is assured. Place concrete within the time limit during which the excavation remains clean and stable and the concrete maintains the required slump. If an unplanned cold joint occurs, roughen and clean the surface of construction joints, provide reinforcing dowels and continue concreting at the direction of the ENGINEER. During concrete placement, the displaced slurry shall be pumped to holding tanks. Do not spill onto or contaminate the site. Do not use excavated slurry pits, unless accepted by ENGINEER.

4. Dispose of the slurry off site in a legally acceptable manner. Submit approval of governing agencies with jurisdiction.

E. Concreting Methods:

1. Place concrete by tremie methods or by pumping.

2. Tremie or pump pipe shall be made of steel and have watertight joints. Tremie pipe shall have a minimum diameter of 8 inches, and pump pipe shall have a minimum diameter of 4 in.

3. A capped or pig-plugged tremie or pump pipe shall be inserted and seated in the excavation at the bottom of the pier before the commencement of concrete placement.

4. The bottom of a capped pipe or tremie shall be tightly closed with a bottom plate or other acceptable device. Place enough concrete in the pipe or tremie to prevent the flow of slurry into it.

5. If a pig is used, set the open tremie pipe loosely on the bottom. Insert the pig at the top and then place concrete pushing the pig ahead, separating the concrete from the drilled pier excavation fluid. Take care to ensure that the pig is properly sized to fit in the pipe, and keep the concrete separate from the slurry so that all slurry is expelled from the pipe during the initial charging process. When the pipe is filled with concrete, lift the pipe off the bottom the minimum amount needed to start the concrete flowing. Once concrete flow has started, place concrete into tremie at a fast enough rate to maintain a positive head of concrete inside the pipe relative to slurry level outside pipe.

6. Embed tremie or pump pipe a minimum of 10 feet in the concrete to maintain a seal throughout concrete placement to prevent reentry of slurry suspension into the pipe. If the seal is lost, withdraw pipe, recreate the seal by embedding a capped tremie or pump pipe I0 feet into the existing concrete, and restart the tremie operation.

7. Displace out of the pier or remove from the pier the first portion of concrete that comes to the top of the pier that contains concrete contaminated with slurry until uncontaminated concrete is visible. Add or remove concrete to the specified cutoff level.

8. Raise or lower the tremie pipe in a manner that does not break the seal and does not cause pier defects, such as vertical bleed channels or piping, or segregation.

9. Do not use aluminum pipe or equipment for placing concrete.

10. Report in graphical format the theoretical and actual volume of concrete placed versus depth at elevation intervals not exceeding the shaft diameter.

F. Inspection and Testing:

1. ENGINEER will inspect drilled pier installations and determine the actual final bearing level. Inspection and testing will be done using the criteria set forth in the Contract Documents.

2. Perform slurry testing by the test methods in Table B. ENGINEER will inspect the CONTRACTOR's testing. Provide all test equipment required for the tests specified in Article 2.6. Have available at the site a slurry sampler capable of obtaining slurry samples at any depth within the drilled pier excavation.

3. The testing agency will sample and test concrete in accordance with Section

03350, Concrete Testing.

3.6 PLACEMENT OF ANCHORAGE EMBEDMENTS

A. Before placement, all anchorage components shall be free of contaminating material or unacceptable corrosion.

B. Place anchorage components either by pushing into the fresh concrete or by setting in the open shaft. If the anchorage components are not easily pushed into the fresh concrete, the concrete shall be vibrated to ensure full contact between anchorages and concrete.