1、10-06M 31 63 26 - 1 SECTION 31 63 26 DRILLED CAISSONS SPEC WRITER NOTE: Delete between /-/ if not applicable to project. Also delete any other item or paragraph not applicable in the section and renumber the paragraphs. PART 1 - GENERAL 1.1 DESCRIPTION This section specifies excavation and concrete
2、required for construction of foundation caissons. SPEC WRITER NOTE: Obtain from Structural Engineer bearing material name which shall be same nomenclature as appears in SUB-SURFACE EXPLORATION REPORT. Insert name in following paragraph. 1.2 DEFINITIONS Satisfactory Bearing Material: _ and is assumed
3、 to occur at bottom of caisson elevations shown. 1.3 RELATED WORK A. Materials testing and inspection during construction: Section 01 45 29, TESTING LABORATORY SERVICES. B. Safety requirements and blasting operations: Section 00 72 00, GENERAL CONDITIONS, Article, ACCIDENT PREVENTION. C. Subsurface
4、Investigation: Section 01 00 00, GENERAL REQUIREMENTS, Article, PHYSICAL DATA D. Earth excavation: Section 31 20 00, EARTH MOVING. E. Concrete, including materials and mixes: Section 03 30 00, CAST-IN-PLACE CONCRETE. 1.4 CONTRACT BASIS A. Contract price for caissons will be based upon total length f
5、or each type of caisson shown. Length of caissons will be measured from bottom elevation to top elevation of the caisson. The diameter of the caisson is defined as the minimum diameter of the shaft. 1. Adjustment of contract price shall be based upon total length of each type of caisson placed and n
6、ot on the length of individual caissons. When the total length of each type of completed caisson is greater or less than the length shown due to unsuitable soils or design modifications by the Resident Engineer, contract price adjustment will be made in accordance with Articles, DIFFERING SITE Provi
7、ded by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-06M 31 63 26 - 2 CONDITIONS, CHANGES and CHANGES-SUPPLEMENT of the GENERAL CONDITIONS as applicable. 2. Contract price and time will be adjusted in accordance with Articles, DIFFERING SITE CONDITIONS, CHA
8、NGES and CHANGES-SUPPLEMENT of the GENERAL CONDITIONS as applicable, when artificial materials that are not shown are encountered. 1.5 CLASSIFICATION OF EXCAVATION A. Soil/Weathered Rock Excavation: SPEC WRITER NOTE: The requirements for track mounted power excavators may vary. Discuss with soils co
9、nsultant and modify as necessary. Soil or weathered rock that can be reasonably excavated with the rock auger, i.e. rock auger advancement greater than 150 mm (6 inches) per 15 minutes (see rock auger refusal, 1.5.C-2, below) B. Sloping Weathered Rock Excavation: Excavation of soil/weathered rock th
10、at can typically be excavated with the rock auger, except when the steeply sloping orientation of the stratum causes the rock auger to run askew. C. Rock Excavation: 1. Excavation of material that meets the rock auger refusal criteria and requires the rock core barrel or other hard rock excavation t
11、echniques for removal. 2. Rock auger refusal is defined as a penetration rate of less than 150 mm (6 inches) in 15 minutes, while operating a caisson drilling rig, rated with a torque capacity of at least 110 kN-meters (1,000,000 inch-pounds), applying a continuous down pressure of at least 220 kN (
12、50,000 pounds), equipped with a rock auger that contains conical carbide-tipped (“Kennemetal”) teeth. D. Nominal Soil or Weathered Rock Seams: Nominal soil or weathered rock seams below rock auger refusal will be excavated and considered as rock for rock excavation quantities. A nominal soil or weat
13、hered rock seam is one which is less than 600 mm (2 feet) thick. Where soil or weathered rock seams or voids of 600 mm (2 feet) or greater are excavated within a mixed rock/soil or rock/weathered rock profile, excavation is classified as soil/weathered rock excavation until rock auger refusal is aga
14、in established. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-06M 31 63 26 - 3 1.6 MEASUREMENT AND PAYMENT FOR ROCK EXCAVATION A. Measurement: Excavation type in units of length shall be considered to change at the upper contact with a different
15、 excavation type as defined by section 1.5. B. Payment: Contract unit rates per length of each type of caisson shall be provided for each excavation condition type noted above in Section 1.5. Contract price and time will be adjusted for overruns or underruns in accordance with Articles, DIFFERING SI
16、TE CONDITIONS, CHANGES and CHANGES-SUPPLEMENT of the GENERAL CONDITIONS as applicable. C. Payment for Differing Site Conditions: No payment will be made for any rock excavation beyond caisson limits unless additional excavation is directed by the Resident Engineer. When rock excavation, as classifie
17、d, is encountered, contract price and time will be adjusted in accordance with Articles, DIFFERING SITE CONDITIONS, CHANGES and CHANGES-SUPPLEMENT of the GENERAL CONDITIONS as applicable. SPEC WRITER NOTE: Obtain following allowable tolerances from Structural Engineer. 1.7 TOLERANCES Install caisson
18、s with not more than the lesser of 1/24th of caisson shaft diameter or 75 mm (3 inches) from design center location. Caissons shall not be out of plumb more than 25 mm (1 inch) in 3000 mm (10 feet) for the full depth. 1.8 SUBMITTALS A. Submit in accordance with Section 01 33 23, SHOP DRAWINGS, PRODU
19、CT DATA, AND SAMPLES. B. Before beginning work, submit a detailed location plan and description of the proposed method of caisson installation, all of which shall be subject to the review and approval of the Resident Engineer. C. Shop Drawings shall comply with ACI 315 “Manual of Standard Practice f
20、or Detailing Reinforced Concrete Structures“. Furnish shop drawings prepared by a Professional Engineer licensed in the State of the project for the detailing, fabricating, bending, and placing of concrete reinforcement. D. /Submit a detailed plan showing load test arrangement, location, and Contrac
21、tors qualifications and results for review and approval by the Resident Engineer./ E. Reports: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-06M 31 63 26 - 4 1. Caisson record: Data as specified. 2. Rock excavation: Data as specified. 3. Soil Te
22、sting Agency Reports shall be issued showing material type and allowable bearing capacity at bottom of shaft within 24 hours after testing/observing each caisson. 4. Certified, “Caisson Field Record“ for each caisson recording actual elevation of bottom, elevation of rock (if applicable), final cent
23、erline location of top, variation of shaft from plumb, bell dimension (if applicable), result of all tests and observations performed, material type and actual allowable bearing capacity of bottom, depth of socket into rock, levelness of bottom, seepage of water, still water level (if allowed to flo
24、od), elevation (top and bottom) of lining left in place, variation of shaft diameter (from those shown), and evidence of seams, voids or channels below bottom. 1.9 APPLICABLE PUBLICATIONS A. Publications listed below form a part of this specification to extent referenced. Publications are referenced
25、 in text by basic designation only. B. American Society for Testing and Materials (ASTM): A36/A36M-05 Standard Specification for Carbon Structural Steel A283/A283M-03 Standard Specification for Low and Intermediate Tensile Strength Carbon Steel Plates A615/A615M-06a. Standard Specification for Defor
26、med and Plain Carbon-Steel Bars for Concrete Reinforcement A929/A929M-01 Standard Specification for Steel Sheet, Metallic-Coated by the Hot-Dip Process for Corrugated Steel Pipe A996/A996M-06a. Standard Specification for Rail-Steel and Axle-Steel Deformed and Bars for Concrete Reinforcement C33-03.
27、Standard Specification for Concrete Aggregates C94/C94M-05 Standard Specification for Ready-Mixed Concrete C150-05 Standard Specification for Portland Cement C494/C494M-05a. Standard Specification for Chemical Admixtures for Concrete Provided by IHSNot for ResaleNo reproduction or networking permitt
28、ed without license from IHS-,-,-10-06M 31 63 26 - 5 C618-05 Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete C989-05 Standard Specification for Ground Granulated Blast-Furnace Slag for Use in Concrete and Mortars C1017/C1017M-03 Standard Specification
29、for Chemical Admixtures for Use in Producing Flowing Concrete C. American Concrete Institute (ACI): 211.1-91 (2002) Standard Practice for Selecting Proportions for Normal, Heavyweight and Mass Concrete 301-05. Specifications for Structural Concrete 315-99. Manual of Standard Practice for Detailing R
30、einforced Concrete Structures D. American Welding Society (AWS): D1.1 (2006) Structural Welding Code Steel PART 2 - PRODUCTS SPEC WRITER NOTE: Make material requirements agree with applicable requirements specified in the referenced Applicable Publications. Update and specify only that which applies
31、 to the project. 2.1 MATERIALS SPEC WRITER NOTE: Delete this Article if unreinforced-concrete drilled piers are used. A. Steel Reinforcement: ASTM A 615/A 615M, or 996, Grade 60, deformed. B. Portland Cement: ASTM C 150, Type I or II. SPEC WRITER NOTE: Select mineral or cementitious admixtures from
32、two subparagraphs below if permitted. Ready-mix plant blends fly ash or slag with portland cement. C. Fly Ash/Slag: 1. Fly Ash Admixture: ASTM C 618, Class C or F. 2. Ground Granulated Blast-Furnace Slag: ASTM C 989, Grade 100 or 120. D. Normal-Weight Aggregate: ASTM C 33, uniformly graded, 19 mm (3
33、/4-inch) maximum aggregate size. E. Water: Potable, complying with ASTM C 94/C 94M requirements. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-06M 31 63 26 - 6 F. Admixtures: Certified by manufacturer to contain not more than 0.1 percent water-s
34、oluble chloride ions by mass of cementitious material and to be compatible with other admixtures and cementitious materials. Do not use admixtures containing calcium chloride. SPEC WRITER NOTE: If desired, select admixtures from subparagraphs below. 1. Water-Reducing Admixture: ASTM C 494, Type A. 2
35、. Water-Reducing and Retarding Admixture: ASTM C 494, Type D. 3. High-Range, Water-Reducing Admixture: ASTM C 494, Type G. 4. Plasticizing and Retarding Admixture: ASTM C 1017, Type II. G. Steel Casings: All casing shall meet ASTM A 283, Grade C; or ASTM A 36, carbon-steel plate, with joints full-pe
36、netration welded according to AWS D1.1, or ASTM A 929/A 929M, steel sheet, zinc coated corrugated steel. The Contractor shall design shells to withstand drilling forces and earth pressures and reinforce the bottom cutting edge as required for proper drilling and sealing of the shells into the rock.
37、The cutting edge shall be capable of coring through at least 3000 mm (10 ft) of broken or solid rock. A minimum of 2% out of roundness of the diameter shall be considered in the design of the shell. All seams shall be welded and watertight H. Concrete Mix: Prepare design mixes according to ACI 211.1
38、 and ACI 301 for each type and strength of concrete determined by either laboratory trial mix or field test data bases. Use a qualified testing agency for preparing and reporting proposed mix designs for laboratory trial mix basis. Proportion mixes according to ACI 211.1 and ACI 301 to provide norma
39、l-weight concrete with the following properties: 1. Compressive Strength (28 Days): 34.5 MPa (5000 psi). 2. Minimum Slump: Capable of maintaining a slump of 125 mm (5 inches) plus or minus 25 mm (1 inch). 3. Do not air entrain concrete for caissons. 4. Limit water-soluble, chloride-ion content in ha
40、rdened concrete to 0.15/0.3 percent by weight of cement. 5. Concrete-mix design adjustments may be considered if characteristics of materials, project conditions, weather, test results, or other circumstances warrant. Resubmission and approval of proposed changes to concrete-mix proportions is the r
41、esponsibility of the Contractor. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-06M 31 63 26 - 7 I. Concrete Mixing: Measure, batch, mix, and deliver concrete according to ASTM C 94/C 94M, and furnish batch ticket information. Do not add water to
42、 concrete mix after mixing, unless a procedure per ACI 301 is submitted to and approved by the Resident Engineer. Maintain concrete temperature less than 32 degree Celsius (90 degree Fahrenheit). PART 3 - EXECUTION 3.1 GENERAL A. Size: Minimum sizes and types of caissons are shown. Proposal to use c
43、aissons of sizes and types different from those shown may be accepted if submitted in writing to Resident Engineer for approval and provided the following conditions are met: 1. Least dimension of caisson is equal to or greater than least dimension shown. 2. Enlargement at base of caisson is in bell
44、-form with dimensions equal to or greater than minimum shown. SPEC WRITER NOTE: Consult Structural Engineer for bearing value required in following paragraph (3). 3. If volume of caisson as constructed is greater than that shown, bearing area at base is increased so that additional weight is distrib
45、uted to bearing material at no more than _ kPa ( _ ksf). 4. Entire caisson receives full lateral support from surrounding material. B. Changes: Requests for change in size or type of caisson from those shown shall be accompanied by calculations and other documentation necessary to show that proposed
46、 changes will meet load requirements. Do not proceed with changes before receiving written approval from Resident Engineer. C. Temporary Steel Casings: Install casings for protection of workers and inspection personnel, for prevention of cave-ins or displacement of earth walls, and for retention of
47、ground water. D. Defective Casings: Do not install buckled, distorted or otherwise damaged casings. Replace casings damaged or disturbed during construction, casings that are not mud-tight or otherwise not in accordance with drawings or specifications, at no additional cost to the Government. Provid
48、ed by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10-06M 31 63 26 - 8 E. Survey: Registered Professional Land Surveyor or Registered Civil Engineer, specified in Section 01 00 00, GENERAL REQUIREMENTS, shall establish lines and levels and stake caisson locat
49、ions. 3.2 EXCAVATION A. Excavation and construction methods shall result in minimum disturbance of surrounding material and full lateral support of caissons by surrounding material. B. Remove boulders and rock in caissons such as rock seams underlain with soil seams, sloping rock or rock otherwise unsatisfactory for bearing. C. If materials with satisfactory beari
