703 - DRILLED SHAFTS
700-13 (6) Filling Core Holes. Fill core holes by pre ssure grouting with non-shrink grout described in subsection
703.2b . Use a pipe extending to the bottom of the hole to fill it from the bottom to the top.
7.Filling Pipes. After completing sonic testing and final acceptance of the drilled shaft is made, fill the sonic testing pipes with the specified non-shrink grout. If the Contractor can expel enough water from sonic testing pipes leaving 2 feet or less of standing water in the sonic testing pipe, grout may free fall to the bottom of the pipe. If more than 2 feet of water remains in the bottom of the sonic testing pipe, prevent the grout from free falling through the water using a tremie tube extending to the bottom of the sonic testing pipe.
j.Backfill. When a temporary casing and a permanent casing are used, backfill the space (between casings) with the material specifi ed in the Contract Documents: Granular material fine enough to fill the entire volume; or Grout or flowable fill described in subsection 703.2b . If the space contains water, use a pump with an exte nsion pipe or tremie (extending to the bottom of the space) to fill the space. If the space is dry, the grout/f lowable fill may free fall to th e bottom of the shaft. Fill the space with grout/flowable fill to the to p of the casing, then, completely remove the temporary casing. When the Contract Documents do not specify a material for backfill, use the granular material before extracting the temporary casing. After extracting the temporary casing, fill th e rest of the space with granular material. 703.4 MEASUREMENT AND PAYMENT
a.Drilled Shafts. The Engineer will measure drilled shafts by th e linear foot measured from the bottom of the rock socket to the top of the completed drilled shaft. The Engineer will not consider a request for additional compensation, unless the overall length of a drilled shaft changes by more than 20%.
b.Permanent Casing. The Engineer will measure the accepted permanent casing by the linear foot, if a permanent casing is required, but not specified in the Co ntract Documents. The Engineer will not measure the permanent casing if: Contract Documents requir e Drilled Shafts (Cased). Contractor uses the casing for their convenience. Casing is a temporary casing.
c.Sonic Test (Drilled Shaft) (Set Price).
1.Sonic Testing specified in Contract Documents. When shown in the Contract Documents, the Engineer will measure each designated sonic test, per shaft (i.e. so nic logging between all possi ble combinations of pipes represents a single sonic test).
2.Sonic Testing requested by the Engineer. When the Engineer requests sonic tests not shown in the Contract Documents, and the sonic testing indicates the concrete is acceptable, the Engineer will measure each sonic test, per shaft (i.e. sonic logging between all possible combinations of pipes represents a single sonic test). When the Engineer requests sonic testing not shown in the Contract Documents, and the sonic testing indicates defective concrete in the drilled shaft, the Engineer will not measure for payment the sonic testing of that shaft. When the Engineer requests sonic testing not shown in the Contract Documents, the sonic testing indicates defective concrete in the drilled shaft, th e Engineer requests cores from the shaft, and the cores reveal unsound concrete, the Engineer will not measure for payment the sonic testing or cores for that shaft. When the Engineer requests sonic testing not shown in the Contract Documents, the sonic testing indicates defective concrete in the drilled shaft, and the Engineer requests cores from the shaft, and the cores reveal sound concrete, the Engineer will measur e for payment each sonic test, per shaft (i.e. sonic logging between all possible combinations of pipes represents a single sonic test). The Engineer will also pay for the cores as Extra Work according to SECTION 104 . 703 - DRILLED SHAFTS 700-14
3.Core Hole (Investigative) specified in the Contract Documents. When shown in the Contract Documents, the Engineer will measure the investigative core hole by the linear foot, from the existing ground surface to 6 feet below the drilled shaft tip elevation.
d.Payment. Payment for "Drilled Shaft" and "Core Hole (I nvestigative)" at the contract unit prices, and "Permanent Casing" and "Sonic Test" at the contract set unit prices is fu ll compensation for th e specified work. If the Engineer lengthens the drilled shaft during co nstruction, the Engineer will measure and pay for additional reinforcing steel as Extra Work according to SECTION 104 . 704 - PILING
700-15 Section 704
PILING 704.1 DESCRIPTION Drive the specified types of piles to the penetration and bearing values shown in the Contract Documents. B I D I T E M S U N I T S P i l e s ( * ) ( * * ) L i n e a r F o o t Test Piles (*) (**) Linear Foot Test Piles (Special) (*) (**) Linear Foot Cast Steel Pile Points Each Pre-Drilled Pile Holes Linear Foot *Type: Cast-In-Place Concrete, Prestressed Concrete, Steel or Steel Sheet, Corrugated Metal Sheet + **Size +Black or Galvanized 704.2 MATERIALS Provide materials that comply w ith the applicable requirements. Concrete ................................................................................................................ SECTIONS 401 & 402 Aggregates for Concre te Not On Grade ................................................................ SECTIONS 1102 Prestressed Conc rete Piles ..................................................................................... DIVISION 700 Steel Bars for Concre te Reinfor cement ................................................................. DIVISION 1600 Steel Piling and Steel Pile Points ........................................................................... DIVISION 1600 Type B Preformed Expa nsion Joint Filler ............................................................. DIVISION 1500 Paint Mate rials ....................................................................................................... DIVISION 1800 704.3 PILE DRIVING EQUIPMENT
a.General. Pile driving hammers other than drop hammers shall be of the size needed to develop the energy required to drive piles at a penetration rate of not less than 0.10 inches per blow at the minimum driving resistance according to the approp riate pile driving formula in TABLE 704-1 . In addition to all other requirements, single and doubl e acting diesel hammers and air/steam hammers require the following. (1) Open-End (Single Acting) Diesel Hammer. Equip ope n-end (single acting) diesel hammers with a device such as rings on the ram or a scale (jump stick) extending a bove the ram cylinder, to permit the Engineer to visually determine hammer stroke at all times during pile driving operation. Also, provide the Engineer a chart from the hammer manufacturer equating stroke and blows per mi nute for the open-end diesel hammer to be used.
2.Closed-End (Double Acting) Diesel Hammer. Eq uip closed-end (double acting) diesel hammers with a bounce chamber pressure gauge, mounted near ground level so as to be easily read by the Engineer. Also, provide the Engineer a chart, calibrated to actual hammer performance, equating bounce chamber pressure to either equivalent energy or stroke for the closed-end diesel hammer to be used. (3) The weight of the striking part of air/steam hammers used shall be a minimum of ⅓ the weight of the pile and drive cap, and in no case shall the striking part have a weight less than 2,750 pounds.
b.Hammers for Steel Piles, Steel Sheet Piles a nd Shells for Cast-in-Place Concrete Piles. If a gravity hammer is used for driving steel piles, steel sheet and shells for cast-in-place concre te piles, use one with a minimum weight of 3,500 pounds. In no case may the weight of the gravity hammer be less than the pile being driven plus the weight of the driving cap. In lieu of weighing the hammer, a certification may be provided by the Contractor. Equip all gravity hammers with hammer guides to maintain concentric impact on the drive head or pile cushion. Regulate the fall to avoid injury to the piles. The fall shall be a maximum of 12 feet. If diesel or air/steam hammers are used, the maximum fall sh all be 90% of the maximum fall recommended by the hammer manufacturer. 704 - PILING
700-16 If steam or diesel hammers are used, its rated gross energy in foot-pounds shall be a minimum of 2 ½ times the
weight of the pile in pounds. The hammer shall develop a minimum of 6,000 foot-pounds of energy per blow.
c.Hammers for Pre-stressed Concrete Piles. Unless otherwise provided, drive pre-stressed concrete piles with a diesel or air/steam hammer that can develop an energy per blow at each full stroke of the piston of a minimum of 1 foot-pound for each pound of weight driven. The hammer shall develop a minimum of 6,000 foot- pounds of energy per blow.
d.Vibratory Hammers. Vibratory hammers may only be used when specifically allowed by the Contract Documents or in writing by the Engineer. If approved, vibratory hammers shall be used in combination with pile load testing and re-tapping with an impact hammer. In addition, 1 of every 10 piles driven with a vibratory hammer shall be re-tapped with an impact hamm er of suitable energy to verify that acceptable load capacity was achieved.
e.Additional Equipment. The plant and equipment provided for air/steam hammers shall have sufficient capacity to maintain, under working conditions, the pressure at the hammer specified by the manufacturer. In case the required penetration or bearing is not obtained by the use of a hammer complying with the above minimum requirements, provide a hammer of greater energy or when permitted, resort to jetting or pre-drilling at Contractor expense. Use of the pile driving analyzer may be required when minimum requirements are not obtained or results are doubtful.
f.Leads. Construct pile-driving leads to afford freedom of movement for the hammer. Hold them in position with guys or stiff braces to sup port the pile during drivin g. Except where piles ar e driven through water, use leads of sufficient length that the use of a follower shall not be necessa ry. Leads shall be of sufficient length to allow them to be spiked into the ground at the onset of driving.
g.Hammer Cushion. Equip all impact pile driving equipment except gravity hammers with a suitable thickness of hammer cushion material to prevent damage to the hammer or pile and to maintain uniform driving behavior. Use hammer cushions made of durable, manufactured material that shall retain uniform properties during driving. Wire rope and asbestos hammer cushions are pr ohibited. Place a striking plat e on the hammer cushion to maintain uniform compression of the cushion material. In spect the hammer cushion in the presence of the Engineer when beginning pile driving at each stru cture or after each 100 hours of pile dr iving, whichever is more frequent. Replace the hammer cushion whenever there is a reduction of hammer cushion thickness exceeding 25% of the original thickness, or when the cushion begins deteriorating, tearing, etc., before continuing driving. The following are acceptable types of p ile cap material. Other materials may be used with approval of the Bureau of Construction and Materials.
1.Micarta (Conbest) - This is an electrical insulati ng material composed of fabric and phenol. Replace when it starts to powderize or when it disintegrates into various layers.
2.Nylon (2-inch thick blocks) - Occasional vertical cr acking is not detrimental. However, replace after the cushion develops horizontal cracks.
3.Hamortex (metallized paper reels) - Pay attention as it may compress or disintegrate.
4.Force 10, Forbon, and Fosterlon - These materials are provided by manufacturers of pile driving equipment.
5.Aluminum - Aluminum is often us ed to separate layers of softer cushioning material. Replace once the aluminum is deformed or broken.
6.Wood (plywood or hardwood) should only be used with gravity hammers.
h.Pile Driving Head. Fit piles driven with impact hammers w ith an adequate driving head to distribute the hammer blow to the pile head. Axially align the drivin g head with the hammer and the pile. The driving head is guided by the leads and shall not be free swinging. The driving head shall fit around the pile head in a manner that prevents transfer of torsional force during driving while maintaining proper alignment of hammer and pile.
i.Water Jets. When jets are permitted, the number of jets and the volume and pressure of water at the jet nozzle shall be sufficient to freely erode the material adjacent to the pile. Use a plant with sufficient capacity to deliver a minimum of 100 pounds per square inch pressure at ¾-inch jet nozzles at all times. At a minimum of 5 feet before the desired penetr ation is reached, withdraw the jets and driv e the piles to secure the final penetration with an approved hammer. 704 - PILING
700-17 704.4 Construction Requirements
a.Order Lists, Piles and Test Piles. The order list is the same as the estimated quantity (number and length of piles) shown in the Contract Documents. For piles and test piles, provide the Engineer with the completed "Pile and Driving Equipment Data" sheet a minimum of 3 weeks before the scheduled date of drivin g piling. The Engineer will forward this information for Test Pile (Special) to the Chief Geologist. When a restrike is required by the Engineer, follow subsection 704.4e. for restrike procedures. Provide piles for the structure according to the order list (number and length of piles) prepared by the Engineer. Drive the specified test piles at the locations shown in the Contract Documents. The Engineer will use the test pile information to determine the pile tip elevation. If multiple hammers are used on a project requiring test pile or test pile (special), drive a test pile or test pile (special), whichever is specified, with each hammer.
b.Test Pile (Special). Pile Driving Analyzer (PDA). The En gineer will use the PDA to monitor the driving of the test piles (special). Provide the Engineer with the completed "Pile and Driving Equipment Data" sheet a minimum of 3 weeks before the scheduled date of drivi ng piling. The Engineer will forward this information to the Chief Geologist. In order to mobilize the PDA, notify the Engineer a minimum of 5 working days before driving the test piles (special). Prior to driving the test pile (special), the Engineer will require approximately 1½ hours to prepare the test piling (special) and install the dynamic measuring eq uipment. If with prior approval, the piles are to be welded prior to the Engineer attaching the testing equipment, provide the Engineer with safe and reasonable means of access to the pile for preparing the pile and attaching the instruments. When a restrike is required by the Engineer, follow subsection 704.4e.(3). for restrike procedures. To obtain the estimated ultimate loads, the Engineer will use the PDA to take dynamic measurements as the test pile (special) is driven to the required driving resistance. If non-axial driving is indicated by dynamic test equipment measurements, immediately realign the driving sy stem. The Engineer will use the PDA results to provide the Contractor with a blow count for production driving.
c.Driving Piles. Drive the piles with a gravity hammer, a diesel hammer, an air/steam hammer or a combination of pre-drilled holes or water jetting an d a hammer. Use equipment that complies with subsection 704.3 . Drive the piles at the locations and to the vertical or battered lines shown in the Contract Documents. Use leads of sufficient length to allow them to be spiked into the ground at the onset of driving the pile. Do not drive piles until the footing, webwall or abutment excavation is completed. Drive all of the piles required for the footing or abutment before placing any concrete in the footing or abutment, unless the foundation is a minimum of 20 feet away or has cured a minimum of 24 hours. When specified, drill pile holes before driving the pile s. Drill the holes accurately so that the piles are set as shown in the Contract Documents. The maximum size of the pre-drilled holes is equal to the diameter of the pile plus 3 inches. The depth of pre-drilled pile holes is show n in the Contract Documents. If pre-drilled pile holes are not specified, the Contractor may choose to pre-drill pile holes, provided the Engineer approves the Contractor’s method and limits. After the piles are driven to their fina l positions in the pre-drilled hole s, fill the holes with loose sand or material specified in the Cont ract Documents. If concrete is specifi ed, allow sufficient concrete slump and provide vibration to fill all voids around the pile. Drive all pile heads perpendicular to the longitudinal axis of the pile s to prevent eccentric impacts from the drive head of the hammer. Use pile caps on all piles during the pile driving operations. For pile caps of concrete piles and prestressed concrete piles, use a suitable cushion next to the pile head that fits into a casting that supports a timber shock block. On pile caps for steel piles and steel sheet piles, provide grooves in the bottom of the cap to accommodate the shape of the pile s to hold the axis of piles in line with the axis of the hammer. On pipe pile, use a helmet with a minimum interior guide of 6 inches. If specified, use the type of cast steel pile points shown in the Contract Documents. Use pile points that provide full bearing for the piles. Provide an experienced we lder to attach the cast steel pile points to the piles. Use full-length piles where practicable. It is preferred that steel piling is not spliced. Splices may be made with the permission of the Engineer, or when shown in the Contract Documents. Make splices as shown in the Contract Documents. Use an approved welding process as provided in DIVISION 700 to make the splices. Provide an experienced welder qualified under SECTION 713 to make the welded splices for structural steel piling and shell piling. Correct or replace any failure in the splice at own expense. 704 - PILING
700-18 Avoid extensions, splices or build-ups on prestressed concrete piles whenever possible. When splicing is
necessary, make them as shown in the Contract Documents. If the pile driving procedure causes crushing or spallin g of the prestressed concrete piles, or deformation of the steel piles, remove and replace the damaged piles with new, longer piles. A second p ile may be driven adjacent to the damaged pile, when approved by the Engineer and can be accomplished without detriment to the structure. Do not force misaligned piles into proper position. Re move and replace piles driven out of their proper location with new, longer piles. If the driven pile is 35 feet or less in length, the maximum allowable variation from the vertical or battered lines shown in the Contract Documents is ¼ inch per foot of length. If the driven pile is greater than 35 feet in length, the maximum allowable variation from the vertical or battered lines shown in the Contract Documents is ⅛ inch per foot of length. The maximum allowable variation on the head of the driven pile from the position shown on the Contract Documents is 2 inches for piles used in bents, and 6 inches for foundation piles. Drive all piles in the orientation shown on the Plans. If the axial orientation of the pile rotates or twists by more than 10°, the Field Engineer will contact the Bureau of Structures and Geotechnical Services. Re-drive all piles pushed up by the driving of adjacent piles, or by any other cause.
d.Bearing Values and Required Penetration. Drive the piling to attain, as a minimum, the specified bearing value, penetration and pile tip elevation. Stop dr iving the piling (regardless of the penetration) if 1½ times the specified minimum driving resistance is attained. Stop driving the piling if, in the opinion of the Engineer, the specified minimum driving resistance, penetration and pile tip elevation can not be attained without damage to the piling. If the specified minimum driving resistance is not attained with the specified number and length of piling, the Engineer may allow additional piling be driven so that the maximum load on any pile does not exceed its safe carrying capacity. In the absence of loading tests, determine the sa fe bearing values of piles by the formulas in TABLE 704- 1.
Source: Kansas Standard Specifications for State Road and Bridge Construction, 2015 Edition. Pages 344–349 of 978.