510BEARING PILES

New Hampshire Department of Transportation Standard Specifications – 2016 Description

1.1General. This work shall consist of furnishing all types of bearing piles, furnishing pile driving equipment, and driving

bearing piles to the required penetration, and when required, test loading, splicing, and cutting, as shown on the plans or o rdered. Materials & Equipment

2.1Materials

2.1.1 Concrete piles, precast or cast -in-place, shall be Class A unless otherwise shown on the plans and shall conform to Section 520. All concrete for cast -in-place piles shall be designed with the necessary admixtures to maintain the required slump and sufficient workability throughout the entire concrete placement operation. Reinforcing steel shall conform to Section 544. 2.1.2 Steel Piles. 2.1.2.1 Steel H -piles shall conform to the general requirements for rolled steel plates, shapes, sheet piling and bars for structural use, ASTM A6. 2.1.2.2 Unless otherwise specified, high-strength, low-alloy steel shall be furnished for all H-piles and conform to AASHTO M270 (ASTM A709) Grade 50 or ASTM A572 Grade 50. 2.1.2.3 Steel pipe piles shall conform to ASTM A 252, Grade 2, unless otherwise specified. 2.1.2.4 The use of foreign steel will be permitted only after approval by the Engineer upon suitable certification from a recognized domestic laboratory. 2.1.3 Driving points for steel piles shall conform to AASHTO M 103 , (ASTM A27) Grade 65-35 or ASTM A 1 48, Grade 90-60 and shall be as included on the Qualified Products List.

2.2Equipment for Driving Piles.

2.2.1 Pile hammers. Piles may be driven with steam, air, hydraulic or diesel hammers capable of driving piles at least 10 ft. longer than the longest pile length shown on the plans. 2.2.1.1 Gravity hammers shall be subject to approval. When gravity hammers are permitted, the ram shall have a mass between 2,000 and 3,500 lb. and the height of drop shall not exceed 15 ft. In no case shall the weight of gravity hammers be less than the combined weight of drive head and pile. All gravity hammers shall be equipped with hammer guides to ensure concentric impact on the drive head. 2.2.1.2 Open-end (single acting) diesel hammers shall be equipped with a device such as rings on the ram or a scale extending above th e ram cy linder, to permit the Engineer to determine hammer stroke at all times during pile driving operations. The Contractor shall provide the Engineer a chart from the hammer manufacturer equating stroke and blows per minute for the open - end diesel hammer to be used. Closed -end (double acting) diesel hammers shall be equipped with a bounce chamber pressure gauge, in good working order, mounted near ground level so as to be easily read by the Engineer. In addition, for closed-end diesel hammers, the Con tractor shall provide to the Engineer a chart calibrated to actual hammer performance within 90 days of use equating bounce chamber pressure to either equivalent energy or stroke. 2.2.1.3 Non-impact hammers, such as vibratory hammers, or driving aids such as jets, followers, and prebored holes shall not be used unless specifically permitted in writing by the Engineer. When permitted, such equipment and driving aids shall be used only for production piles and only after the pile tip elevation necessary to p rovide the required ultimate resistance is established by load testing and/or test piles driven with an impact hammer. As a condition of approval of the non-impact hammers or driving aids, the Contractor shall perform, at no cost to the State, pile load tests and/or any additional work required to drive test piles, as determined by the Engineer. Installation of production piles with vibratory hammers shall be controlled according to power consumption, rate of penetration, or other means acceptable to the Engineer which assure pile load capacity equals or exceeds the test pile capacity. In addition, one of every ten piles driven with a vibratory hammer shall be retapped with an impact hammer of suitable energy to verify pile capacity. 2.2.1.4 The plant and equipment furnished for steam and air hammers shall have sufficient capacity to maintain, under working conditions, the volume and pressure specified by the manufacturer. The plant and equipment shall be equipped with accurate pressure gauges. The weight of the striking parts of air and steam hammers shall not be less than 1/3 the weight of drive head and pile being driven, and in no case shall the striking parts have a mass less than 2,750 lb. 2.2.2 Driving Appurtenances. 2.2.2.1 Hammer cushion. All pile driving equipment shall be equipped with a suitable thickness of hammer cushion material to prevent pile damage and ensure uniform driving behavior. Hammer cushions shall be made of durable, manufactured materials, provided in accordance with the hammer manufacturer's guidelines except that all wood, wire rope, and asbestos hammer

New Hampshire Department of Transportation Standard Specifications – 2016 cushions are specifically disallowed and shall not be used. A striker plate as recommended by the hammer manufacturer shall be placed on the hammer cushion to ensure uniform compression of the cushion material. The hammer cushions shall be inspected in the presence of the Engineer when beginning pile driving at each substructure element or after each 100 hours of pile driving, whichever is less. Any reduction of hammer cushi on thickness shall be replaced by the Contractor before driving is permitted to continue. 2.2.2.2 Pile cushion. The heads of concrete piles shall be protected by a pile cushion made of plywood or other similar material approved by the Engineer. The minimum plywood thickness placed on the pile head prior to driving shall not be less than 4”. A new pile cushion shall be provided for each pile. In addition, the pile cushion shall be replaced if during the driving of any pile, the cushion is either compressed more than one -half the original thickness or begins to burn. The pile cushion dimensions shall match the cross-sectional area of the pile top. 2.2.2.3 Pile drive head. Piles driven with impact hammers require an adequate drive head to distribute the hammer blow to the pile head. The drive head shall be axially aligned with the hammer and the pile. The drive head should be guided by the leads and not be free-swinging. The drive head should fit around the pile head in such a manner as to prevent transfer of torsional forces during driving while maintaining proper alignment of hammer and pile. 2.2.2.3.1 For steel piling the pile heads shall be cut squarely and a drive head, as recommended by the hammer manufacturer, shall be provided to hold the axis of the pile in line with the axis of the hammer. 2.2.2.3.2 For precast concrete and prestressed concrete piles, the pile head shall be plane and perpendicular to the longitudinal axis of the pile to prevent eccentric impacts. 2.2.2.3.3 For special types of piles, appropriate driving heads, mandrels or other devices shall be provided in accordance with the manufacturers’ recommendations so that the piles may be driven without damage. 2.2.2.4 Leads. Piles shall be supported in line and position with leads while being driven. Pile driver leads shall be constructed in a manner that affords freedom of movement of the hammer while maintaining alignment of the hammer and the pile to ensure concentric impact for each blow. Leads may be either fixed or swinging type. Swinging leads when used shall be fitted with a pile gate at the bottom of the leads. The pile section being driven shall not extend above the leads. The leads shal l be adequately embedded in the ground or the pile constrained in a structural frame su ch as a template to maintain alignment. The leads shall be of sufficient length to make the use of a follower unnecessary and shall be so designed as to permit proper pl acing of batter piles. A free hammer and a rigid double template, which will independently support the pile, may be used when approved in writing by the Engineer. 2.2.2.5 Followers. Followers shall only be used when approved in writing by the Engineer, or when specifically stated in the Contract documents. In cases where a follower is permitted, the first pile in each bent and every tenth pile driven thereafter shall be driven full length without a follower to verify that adequate pile length is being attained to develop the required ultimate resistance. The follower and pile shall be held and maintained in equal and proper alignment during driving. The follower shall be of such material and dimensions to permit the piles to be driven to the length determined necessary from the driving of th e full length piles. The final position and alignment of the first two piles installed with followers in each substructure unit shall be verified to be in accordance with the location tolerances in 3.6.4 before additional piles are installed. 2.2.2.6 Jets. Jetting shall only be permitted if approved in writing by the Engineer or when specifically stated in the Contract documents. When jetting is permitted, the Contractor shall determine the number of jets and the volume and pressure of water at the jet nozzles necessary to freely erode the material adjacent to the pile without affecting the lateral stability of the final in -place jetted pile and adjacent piles. The Contractor shall control, treat if necessary, and dispose of all jet water in a manner satisfacto ry to the Engineer. The Contractor shall be responsible for all damage to the site caused by unapproved or improper jetting operations. When jetting is specifically required in the Contract documents, the jetting plant shall have sufficient capacity to d eliver at all times a pressure equivalent to at least 100 psi at two 3/4 ” jet nozzles. In either case, unless otherwise indicated, jet pipes shall be removed when the pile tip is a minimum of 5 ft. above prescribed tip elevation and the pile shall be driven to the required ultimate resistance with an impact hammer. 2.2.2.7 Preboring. When specified in the Contract documents, the Contractor shall prebore holes at pile locations and to the depths shown on the plans. Prebored holes shall be of a size smalle r than the diameter or diagonal of the pile cross section that is sufficient to allow penetration of pile to the specified depth. If subsurface obstructions, such as boulders or rock layers are encountered, the hole diameter may be increased to the least dimension which is adequate for pile installation. Any void space remaining around any type pile after driving shall be completely filled with sand or other approved material. The use of spu ds, a short strong driven member which is removed to make a hole for inserting a pile, shall not be permitted in lieu of preboring. 2.2.3 Approval of pile driving equipment. All pile driving equipment furnished by the Contractor shall be subject to the approval of the Engineer. All pile driving equipment shall be sized to meet the requirements in 2.2.1. Approval of pile driving equipment by the Engineer will be based on wave equation analysis and/or other judgments. In no case shall the driving equipment be transported to the project site until approval of the Engineer is received in writing. Prerequisite to such approval, the Contractor

New Hampshire Department of Transportation Standard Specifications – 2016 shall submit to the Engineer the necessary pile driving equipment information at least 30 days prior to driving piles. The form for the above information is shown in Figure 1. A f ull size form will be included in the Contract documents or supplied by the Engineer. 2.2.3.1 Wave equation analysis. The criteria, which the Engineer will use to evaluate the driving equipment from the wave equation results, consist of both the required number of hammer blows per inch and the pile stresses at the ultimate pile resistance. The required number of hammer blows indicated by the wave equation at the ultimate pile resistance shall be between 3 and 15 per inch for the driving equipment to be acceptable. The pile stresses which are indicated by the wave equation to be generated by the driving equipment shall not exceed the values where pile damage impends, if the equipment is to be acceptable. 2.2.3.1.1 The point of impending damage in steel piles is defined herein as a compressive driving stress of 90 percent of the yield point of the pile material. For concrete piles, tensile stresses shall not exceed the following: • 3 multiplied by the square root of the concrete compressive strength, f ' c, in pounds per square inch, plus the effective prestress value, in pounds per square inch, 3 f c + prestress.' Compressive stresses shall not exceed 85 percent of the compressive strength minus the effective prestress value (0.85 f ' c - prestress). These criteria will be used in evaluating wave equation results to determine acceptability of the Contractor’s proposed driving system. 2.2.3.1.2 The Contractor will be notified of the acceptance or rejection of the driving system within 14 calendar days of the Engineer’s receipt of the Pile and Driving Equipment Data Form. If the wave equation analysis shows that either pile damage or inability to drive the pile with a reasonable blow count to the required ultimate resistance will result from the Contracto r’s proposed equipment or methods, the Contractor shall modify or replace the proposed methods or equipment until subsequent wave equation analysis indicates the piles can be reasonably driven to the required ultimate resistance, without damage. The Engi neer will notify the Contractor of the acceptance or rejection of the revised driving system within 7 calendar days of receipt of a revised Pile and Driving Equipment Data Form. 2.2.3.1.3 During pile driving operations, the Contractor shall use the approved system. No variations in the driving system will be permitted without the Engineer’s written approval. Any change in the driving system will be considered only after the Contractor has submitted the necessary information for a revised wave equation anal ysis. The Contractor will be notified of the acceptance or rejection of the driving system changes within 7 days of the Engineer’s receipt of the requested change. The t ime required for submission, review, and approval of a revised driving system shall not constitute the basis for a Contract time extension to the Contractor. 2.2.3.2 Alternate approval method. An alternate method of driving equipment approval will be used when either the Contract documents contain a provision that wave equation analysis w ill not be used for approval of driving equipment or the Engineer, in writing, waives the requirement for approval by wave equation analysis of pile driving equipment. The alternate approval method requires that the energy of the driving equipment submitted for approval on the Pile and Driving Equipment Data Form be rated by the manufacturer at or above the appropriate minimum energy level in Table 510- 1 below corresponding to the ultimate pile resistance shown on the plans. 2.2.3.2.1 During pile driving o perations, the Contractor shall use the approved system. If the Engineer determines the Contractor’s hammer is unable to transfer sufficient energy to the pile, the hammer shall be removed from service until repaired to the satisfaction of the Engineer. No variations in the driving system will be permitted without the Engineer’s written approval. Any changes in the driving system will be considered only after the Contractor has submitted a new Pile and Driving Equipment Data Form. The Contractor will be notified of the acceptance or rejection of the proposed driving equipment within 7 calendar days of the Engineer’s receipt of the data form. Table 510-1 - ALTERNATE APPROVAL METHOD Minimum Pile Hammer Requirements Ultimate Pile Resistance Kips Minimum Manufacturer’s Rated Hammer Energy Foot-lbs. 180 and under 9,000 181 to 300 15,000 301 to 420 20,000 421 to 540 24,000 541 to 600 26,000 601 and over Wave Equation Required

New Hampshire Department of Transportation Standard Specifications – 2016 TOWN:______________________________________________BRIDGE NO:________________ ____________ STATE PROJ. NO.:_________________________ DESCRIPTION OF BRIDGE:________________________ PILE DRIVING CONTRACTOR OR SUBCONTRACTOR:_________________________________________ (PILES DRIVEN BY) MANUFACTURER:________________________ MODEL:_______ ______________ HAMMER TYPE:_______________________ SERIAL NO.:___________________ RATED ENERGY :____________________________(ft/Kps) AT____________ LENGTH OF STROKE: _______(ft.) RAM WEIGHT:______(Kps) RANGE IN OPERATING ENERGY ______ TO ____ (FOOT-KIPS) RANGE IN OPERATING STROKE __________ TO _______ (FEET) MODIFICATIONS:_________________________________________________________________ __________________________________________________________________________________ _________________________________________________________________________________

MATERIAL:___________________________________________________________ THICKNESS:______________(in.) AREA: _________________(in2) MODULUS OF ELASICITY (E)_______________________________(P.S.I.) COEFFICIENT OF RESTITUTION (e)_______________________________________

HELMET BONNET WEIGHT:_________________________(lbs.) ANVIL BLOCK PILE CAP

CUSHION MATERIAL: _________________________________________________ THICKNESS:__________________________________________________(in. ) MODULUS OF ELASICITY (E)_______________________________(P.S.I.) COEFFICIENT OF RESTITUTION (e)_______________________________________

PILE TYPE:_____________________________________________________________ ORDERD LENGTH: _____________________________________________ (ft.) WEIGHT/LENGTH: ________________________________________ (lbs./ft.) CROSS SECTIONAL AREA: __________________________________ (in2) PILE DESIGN LOAD: __________________________________________(Ton) PILE DESCRIPTION OF SPLICE:_______________________________________________ ________________________________________________________________________ TIP TREATMENT DESCRIPTION:__________________________________________ ________________________________________________________________ ________ NOTE: IF MANDREL IS USED TO DRIVE THE PILE, ATTACH SEPARATE MANUFACTURER’S DETAIL SHEET(S) INCLUDING WEIGHT AND DIMENSIONS.

SUBMITTED BY:____________________________________________ DATE:____________ FIGURE 1 – PILE AND DRIVING EQUIPMENT DATA FORM

New Hampshire Department of Transportation Standard Specifications – 2016 Construction Requirements

3.1General.

3.1.1 The Contractor shall furnish the piles required after consultation with the Engineer, who will confirm or revise the lengths shown on the plans. When stated in the Contract, the actual lengths for production piles will be determined by the Engineer after the completion of pile load tests. 3.1.1.1 The Contractor shall, at his own expense, supply increased lengths to provide for fresh heading and for such additional length as may be necessary to suit his method of operation. 3.1.2 The length of cast -in-place piles indicated on the plans is for estimating purposes only. The actual length of piles necessary shall be established in the field by driving the shells or pipes to the required ultimate resistance an d penetration. 3.1.3 Unless otherwise permitted, bearing piles shall not be driven until the excavation or fill, whichever the case may be, has been completed. The surface area through which piles are to be driven shall be cleared of all obstructions to d riving. The Contractor’s attention is called to 203.3.7.6 prohibiting placing rock or other objectionable material in the fill. 3.1.4 Individual piles and pile groups shall be installed in such sequence that the soil surrounding the pile is not compacted to the extent that other piles in the group cannot be installed properly. The installation sequence shall be such that groun d movement that would damage adjacent piles, structures or utilities is prevented. 3.1.5 All material fo rced up between the piles shall be removed to the correct elevation before any foundation concrete is placed. 3.1.6 When a pile strikes an obstruction in the upper level of the penetration depth, the Engineer may order exploratory excavation or removal of the obstruction, or both. Backfill material shall be compacted to the density ordered.

3.2Piles.

3.2.1 Precast concrete piles. When items for furnishing and driving precast concrete piles are included in the Contract, the special provisions will specify the required methods of construction and handling. 3.2.2 Cast-in-Place Concrete Piles. 3.2.2.1 Shells. Cast-in-place concrete piles shall be cast in metal shells which have been driven to the specified penetration and driving resistance and which shall remain permanently in place. The shells may be driven with or without a mandrel. 3.2.2.2 The shell shall be both of watertight construction so that the concrete may be placed in the dry and of such thickness and rigidity as to show no signs of harmful dist ortion after being driven. The end closure shall be of adequate strength to resist driving damage and shall be tightly fastened to the shell to prevent water or soil infiltration. Neither the driving points nor the connection welds shall project more than 1/4” beyond the perimeter of the pile tips. 3.2.2.3 Full length shells shall be used where practicable. Shells may be spliced by welding with the approval of the Engineer. All welding shall be in accordance with 550.3.6 and 550.3.16. When built up sections are required either before or during the driving operation, care shall be taken to align the section properly to ensure a straight axis for the pile. The connection shall be watertight. Built up sections during the driving operation shall be made at least 2 ft. above the ground to permit observation of the behavior of the welded connections when driving resumes. 3.2.2.4 The cut-offs shall be made at the elevation indicated on the plans or fixed by the Engineer. After the shell has been driven, it shall be inspected and approved before any concrete is placed. Shells which have been improperly driven or are defective shall be removed and replaced, or repaired to the satisfaction of the Engineer at the Contractor’s expense. 3.2.2.5 Reinforcement. Reinforcing steel shall be of the design shown on the plans, of the unit type rigidly fastened together and lowered into the shell before concrete is placed up to the reinforcement area. The steel shall be secured in such a manner as to ensure its proper location in the finished pile. 3.2.2.6 Placing concrete. All water shall be removed from shells before concrete is placed. Special care shall be taken to place the concrete so as to produce satisfactory bond with the reinforcement and avoid the formation of stone pockets, honeycomb, cold joints, or other such defects. During placing operations, the concrete in the reinforced portion of the pile shall be i nternally vibrated unless otherwise directed. Piles containing reinforcement shall be vibrated to at least the bottom of the reinforcement. 3.2.2.6.1 All driving within 15 ft. of cast piles shall be discontinued for at least 7 days after the concrete has been placed or until the concrete has attained 80 percent of its desired strength. 3.2.3 Steel Piles. 3.2.3.1 Steel piles shall be of the size and shape indicated on the plans, or as directed. They shall be handled and stored in such manner as to avoid deformation or injury.

New Hampshire Department of Transportation Standard Specifications – 2016 3.2.3.2 Mill test reports. To establish proof and ensure that the quality of the material in steel piles complies with the Contract requirements, the Contractor shall submit to the Engineer two certified copies of Heat Number Identified Mill Test Reports showing physical test results and chemical analysis. Should the Contractor be unable to furnish mill test reports as required above, the Contractor shall have a sufficient number (three minimum) of samples tested at an established metallurgical laboratory and furnish to the Engineer three certified copies of the test reports indicating that the material is in compliance with the Con tract documents. Piling shall not be driven until the material has been accepted on the basis of either mill test reports or labor atory testing of samples. 3.2.3.3 Inspection. All piling shall be given a visual inspection at the site before driving to determine that the pile lengths contain no physical defects, such as kinks or buckles that would cause the pile to fail in driving or not perform as intended. 3.2.3.4 Pile points. When driving- points are used, they shall be welded to the piles in the manner recommended by the manufacturer of the points and approved by the Department. The weld joint shall be prepared for a single -bevel groove weld by beveling the edge a minimum of 1/4” at 45 degrees. 3.2.3.5 Splices. 3.2.3.5.1 Each steel pile shall be provided in one piece without splices, unless splices are indicated on the plans, or otherwise permitted. When splicing is permitted, extensions 5 ft. or more in length at the butt end shall be used. 3.2.3.5.2 Splices made on piles that are to be driven in pile bents, shall be made at points that will not be exposed to view, unless otherwise specifically directed or authorized by the Engi neer, in which case they shall be finished to present a neat appearance. 3.2.3.5.3 Unless otherwise directed on the plans or approved, the H-pile splice shall be a complete joint penetration groove butt weld using a 45 degree single-bevel groove weld (AWS B-U4) on the flanges and web. The weld may be made by backgouging to sound weld metal and welding the second side, or by welding from one side using a 3/16” backing bar and 1/4” root opening. 3.2.3.6 Welding. 3.2.3.6.1 All welding shall conform to the applicable requirements of 550.3.16 - Field Welding. 3.2.3.6.2 Welding shall only be performed by qualified welders. 3.2.3.6.3 Welding shall be done with shielded metal arc (SMAW) using E6010 electrodes unless otherwise approved. Low hydrogen electrodes (E7018) may be used with proper storage and joint preparation. At the Contractor’s option, self-shielding flux cored arc welding (FCAW-SS) may be used using E71T-6 or 8 wire for splices and E71T-11 for points.

3.3Determination of Pile Driving Criteria.

3.3.1 Wave equation. The wave equation analysis will be performed by the Engineer to evaluate the pile driving equipment as described in 2.2.3.1, and to establish the driving criteria that are necessary to achieve the required ultimate pile resistance. The driving criteria from the wave equation analysis may be modified during pile installation, based on the results of pile load testing as described in 3.4. Piles shall be driven with the approved driving equipment to th e ordered length or other lengths necessary to obtain the required ultimate pile resistance. Jetting or other methods to facilitate pile penetration shall not be used unle ss specifically permitted either in the Contract documents or approved by the Engineer after revised driving criteria are established from the wave equation analysis. Adequate pile penetration shall be considered to be obtained when the specified driving cri teria are achieved within 5 ft. of the tip elevation based on ordered length. Piles not achieving the specified driving criteria within these limits shall be driven to penetrations established by the Engineer. 3.3.2 Dynamic formula. The driving criteria to achieve the ultimate pile resistance will only be determined by dynamic formula if either the Contract documents contain a provision that dynamic formula shall be used or the Engineer approves dynamic formula use. In such case, piles shall be driven to a length necessary to obtain the ultimate pile resistance according to the following formula: RU = 1.75 (E)1/2 log (10N) - 100 Where: RU = the ultimate pile resistance kips E = the manufacturer’s rated hammer energy ft-lb. at the ram stroke observed in the field. log (10N) = logarithm to the base 10 of the quantity 10 multiplied by N, the number of hammer blows per inch at final penetration blows per inch.

3.4Pile load tests.

Static and/or dynamic load tests shall be performed prior to driving of other piles. 3.4.1 Static load test. When required, load tests shall be performed by procedures set forth in ASTM D 1143 using the quick load test method, except that the test shall be taken to plunging failure or to the test load defined in the Contract, whichever occurs

New Hampshire Department of Transportation Standard Specifications – 2016 first. Testing equipment and measuring systems shal l conform to ASTM D 1143. The Contractor shall submit detailed plans of the proposed loading apparatus for documentation in accordance with 105.02. The apparatus shall be constructed to allow the various increments of the load to be placed gradually without causing vibration to the test pile. When the load test requires the use of tension (anchor) piles, such tension piles shall be of the same type and diameter as the production piles and shall be driven in the location of permanent piles when feasible, except that timber or tapered piles installed in permanent locations shall not be used as tension piles. The safe pile load shall be defined as 50 percent of the failure load. The failure load for the pile shal l be defined as follows: For piles 24 ” or less in diameter or width, the failure load of a pile tested under axial compressive load is that load which produces a settlement of the pile head equal to: SF = S + (0.15 + 0.008D) Where: SF = Settlement at failure in inches D = Pile diameter or width in inches S = Elastic deformation of total unsupported pile length in inches For piles greater than 24” in diameter or width: SF = S + D 3.4.1.1 The top elevation of the test pile shall be determined immediately after driving and again just before load testing to check for heave. All piles which heave more than 1/4” shall be redriven or jacked to the original elevation prior to testing. Unless otherwise specified in the Contract, a minimum three-day waiting period shall be observed between the driving of any anchor piles or the test pile and the commencement of the load test. 3.4.1.2 Upon completion of the load testing, any test or anchor piling not a part of the finished structure, sha ll be removed or cutoff at least 1 ft. below either the bottom of footing or the finished ground elevation if not located within the footin g area. 3.4.2 Pile dynamic load test. 3.4.2.1 The Department will conduct pile dynamic load testing using a Pile Dy namic Analyzer (PDA) to evaluate pile capacity, hammer performance and pile stresses. PDA testing requires mounting two strain gauges and two accelerometer transducers near the pile head which are connected with cables to the PDA processing unit. 3.4.2.2 The number of PDA tests will be determined by the Engineer. At a minimum, PDA testing will be conducted on the first 2 piles per substructure that are driven. PDA testing may also be conducted on additional piles as directed by the Eng ineer. This may include piles that are suspected of being damaged, or piles that do not reach expected embedment depths. The Contractor shall notify the Engineer at least 10 days prior to the start of pile driving so that arrangements can be made with the Geote chnical Section of the Materials and Research Bureau to conduct the PDA testing. 3.4.2.3 The Contractor shall assist the Engineer as required during the PDA testing. This includes providing access while the pile is on the ground to drill the gauge mounting holes, a s afe and reasonable means of access to the pile head for attaching gauges after the pile is in the leads, adequate time for installation of gauges, and any necessary support personnel, equipme nt or materials. A minimum 30-foot long extension ladder shall be provided in order to allow access to the pile head to mount the gauges while the pile is in the leads. It is anticipated that approximately one hour would be necessary to attach the gauges to the pile and to prepare the PDA for testing. A power supply (12 Volts DC or 110 to 125 Volts AC) and extension cords shall be provided by the Contractor for powering the PDA equipment. No payment shall be made for delays in the Contractor’s operations resulting from the PDA testing and for materials, personnel or equipment provided for assisting in the PDA testing. 3.4.2.4 The PDA will be used to evaluate both the Contractor’s driving system and the driving criteria from the wave equation analysis. Based on the results of the PDA data, the Engineer may require the Contractor to modify the pile driving system if the driving operation is found to be in non-conformance with Section 510. 3.4.3 Test piles. Test piles shall be driven when shown on the plans at the locations and to the lengths specified by the Engineer. All test piles shall be driven with impact hammers unless specifically stated in the plans. In general, the specified length of test piles will be greater than the estimated length of production piles in order to provide for variation in soil conditions. The driving equipment used for driving test piles shall be identical to that which the Contractor proposes to use on the permanent piling and shall conform with the requirements of these specifications. The Contractor shall excavate the ground at each t est pile to the elevation of the bottom of the footing before the pile is driven. 3.4.3.1 Test piles shall be driven to a hammer blow count established by the Engineer at the estimated tip elevation. 3.4.3.2 Test piles that do not attain the hammer blow count specified above at a depth of 1 ft. above the estimated tip elevation shown on the plans shall be allowed to “ set up” for 12 to 24 hours or less if directed by the Engineer, before being redriven. A cold hammer shall not be used for redrive. The ha mmer shall be warmed up before driving begins by applying at least 20 blows

New Hampshire Department of Transportation Standard Specifications – 2016 to another pile. If the bearing value is not attained on redriving, the Engineer may direct the Contractor to drive a portion or all of the remaining test pile length and repeat the “ set up” - redrive procedure. Test piles driven to plan grade and not having the required ultimate resistance shall be spliced and driven until the required ultimate resistance is obtained. Redriving shall be restricted to a maximum of 3” additional penetration or a maximum of 50 hammer blows. 3.4.3.3 A record of the driving of the test piles will be prepared by the Engineer. The record will include the number of hammer blows per foot for the entire driven length, the as -driven length of test pile, the cutoff elevation, the penetration into the ground, and any other pertinent information requested by the Engineer. The Contractor shall provide the information listed in Figure 1 to the Engineer for inclusion in the record. If redrive is necessary, the Engineer will record the number of hammer blows per 1” of pile movement for the first foot of redrive. If stated in the Contract, the Contractor shall not order piling to be used in the permanent structure until test pile data have been reviewed and perm anent pile lengths are authorized by the Engineer. The Engineer will provide the pile order list within 7 calendar days after completion of all test pile driving specified in the C ontract documents.

3.5Required Ultimate Resistance.

3.5.1 Piles shall be d riven to the penetration shown on the plans or to a greater depth if necessary to obtain the required ultimate resistance. The driving criteria necessary to achieve the ultimate resistance will be determined by the Engineer based on methods listed in 3.3 and 3.4. 3.5.2 The ultimate resistance of piles driven with a follower shall be considered acceptable only when the follower driven piles attain the same tip elevation as a full length pile driven without a follower, in accordance with the required driving criteria. 3.5.3 Jetting or other methods shall not be used to facilitate pile penetration unless specifically permitted in the Contract plans or in writing by the Engineer. The ultimate pile resistance of jetted piles shall be based on impact driving blow count criteria after the jet pipes have been removed. Jetted piles not attaining the required ultimate resistance at the specified tip elevation shall be spliced if necessary at no cost to the State and driven with an impact hammer until the required dr iving criteria are met. 3.5.4 The ultimate resistance of piles driven with a vibratory hammer shall be based on impact driving blow count of the first pile in each group of 10 piles. Vibrated piles not attaining the required ultimate resistance value at the ordered length shall be spliced, if necessary, at no cost to the State, and driven with an impact hammer until the required driving criteria are met. When the required ultimate pile resistance is attained, the remaining nine piles shall be installed to similar depths with similar vibratory hammer power consumption and rate of penetration as the first pile.

3.6Preparation and Driving.

3.6.1 The heads of all piles shall be plane and perpendicular to the longitudinal axis of the pile before the drive head is attached. The heads of all concrete piles shall be protected with a pile cushion. 3.6.2 During pile driving, the capblock and pile cushion shall be changed as described in 2.2.2 before excessive compression or damage takes place. Approval of a pile hammer relative to driving stress damage shall not relieve the Contractor of responsibility for piles damaged because of misalignment of the leads, failure of capblock or cushion material, failure of splices, malfunctioning of the pile hammer, or other improper construction methods. Piles damaged for such reasons shall be rejected and replaced at the Contractor’s expense when the Engineer determines that the damage impairs the strength of the pile. 3.6.3 Preboring. Spudding, auguring, wet -rotary drilling or other methods of preboring shall be used only when approved by the Engineer and in the same manner as used for any test piles. When permitted, such procedures shall be carried out in a manner which will not impair the carrying capacity of the piles already in place or the safety of existing adjacent structures. 3.6.3.1 Except for end bearing piles, preboring shall be stopped at least 5 ft. above pile tip elevation and the pile shall be driven with an impact hammer in accordance with the driving criteria specified by the Engineer. Where piles are to be end-bearing on rock or hardpan, preboring may be carried to the surface of the rock or hardpan and the piles shall be retapped with an im pact hammer to ensure proper seating. 3.6.3.2 If the Engineer determines that pre-boring has disturbed the load bearing capacity of previously installed piles, those piles that have been disturbed shall be restored to conditions meeting the requirements of this specification by redriving or by other methods acceptable to the Engineer. Redriving or other remedial measures shall be instituted after the preboring operations in the area have been completed. The Contractor shall be responsible for the costs of any necessary remedial measures unless the preboring method was specifically included in the Contract documents and properly executed by the Contractor . 3.6.4 Location and alignment tolerance. The tops of piles at cut-off elevation shall be within 2” of plan locations for bent cap supported by piles and shall be within 6” of plan locations for all piles capped below final grade. Furthermore, the as -driven centroid of load of any pile group at cut-off elevation shall be within 5 percent of the plan location of the designed centroid of load. No pile shall be nearer than 4” from any edge of the cap. Any increase in size of cap to meet this edge distance requirement shall be at the Contractor’s expense.

New Hampshire Department of Transportation Standard Specifications – 2016 3.6.4.1 Piles shall be installed so that the axial alignment of the top 10 ft. of the pile is within 4 percent of specified alignment. For piles that cannot be inspected internally after installation, an alignment check shall be made before installing the last 5 ft. of pile or after installation is completed provided the exposed portion of t he pile is not less than 5 ft. in length. The Engineer may require that driving be stopped in order to check the pile alignment. If the location and/or alignment tolerances specified are exceeded, the extent of overloading shall be investigated and if, in the judgment of the Engineer, corrective measures are necessary, suitable measures shall be designed and constructed by the Contractor at no cost to the State. Pulling laterally on piles to correct misalignment or splicing a properly aligned section on a misaligned section shall not be permitted. 3.6.5 Heaved piles. Elevation readings to check on pile heave after driving shall be made with a survey level at the start of pile driving operations and shall continue until the Engineer determ ines that such checking is no longer required. Level readings shall be taken immediately after the pile has been driven and again after piles within a radius of 15 ft. have been driven. The heave of shell piles shall be measured on a telltale pipe that extends to the bottom of the shell, in order to verify that the shell tip has not heaved. If pile heave is observed, accurate level readings referenced to a fixed datum shall be taken on all piles immediately after installation and periodically thereafter as adjacent piles are driven to determine the pile heave range. All piles that have been heaved more than 0.25 ” shall be redriven to the required resistance or penetration. Concrete shall not be placed in pile casings until pile driving has progressed beyond a radius of 15 ft. from the pile to be concreted. If pile heave is detected for pipe, shell, or tube piles which have been filled with concrete, the piles may be redriven after both the concrete has obtained sufficient st rength and a proper hammer-pile cushion system satisfactory to the Engineer is used. 3.6.6 Installation sequence. The order of placing individual piles in pile groups shall be either starting from the center of the group and proceeding outwards in both directions or starting at the outside row and proceeding progressively across the group. 3.6.7 Unsatisfactory piles. The method used in driving piles shall not subject the piles to excessive or undue abuse producing crushing and spalling of concrete, injurious splitting, splintering, a nd brooming of the wood, or deformation of the steel. Misaligned piles shall not be forced into proper position. Any pile damaged during driving by reason of internal defects, or by improper driving, or driven out of its proper location, or driven below the designated elevation shall be corrected by the Contractor without added compensation by one of the following methods approved by the Engineer:

in conjunction with jacks or other devices for pulling in an effort to remove the whole pile.

embed the pile.

3.6.7.1 Bent piles. Piles which have been bent during installation shall be considered uns atisfactory unless the required ultimate resistance is proven by load tests performed at the Contractor’s expense. If such tests indicate inadequate capacity, corrective measures as determined by the Engineer shall be taken, such as use of bent piles at r educed capacity, installation of additional piles, strengthening of bent piles, or replacement of bent piles. 3.6.7.2 A concrete pile will be considered defective if a visible crack, or cracks, appear around the entire periphery of the pile, or any defect is observed which, as determined by the Engineer, affects the strength or life of the pile.

3.7Cutting off piles. The tops of all piling shall be cut off square to the axis at the elevations shown on the plans or as fixed by

the Engineer. Unless ownership of the pile cut-offs is released to the Contractor by the Engineer, material cut off shall be loaded by the Contractor onto vehicles as directed by the Engineer.

New Hampshire Department of Transportation Standard Specifications – 2016 Method of Measurement

4.1Measurement of pile items will be made in accordance with the following table.

Methods and Units of Measurement Item Method Unit Pile Driving Equipment (All equipment furnished) Unit Pile Loading Tests (On plans and ordered) Each Pile Loading Tests (Not on plans but ordered) Extra Work Furnishing Precast Concrete Piles Total quantity listed on the plans or ordered Linear foot, to the nearest 0.1 of a 1 ft. Driving Precast Concrete Piles Total quantity in place Linear foot, to the nearest 0.1 of a 1 ft. Cast-In-Place Concrete Piles* Total quantity in place Linear foot, to the nearest 0.1 of a 1 ft. Furnishing and Driving Steel Piles Total quantity in place Pound Steel Pile Cut-Off** Total quantity remaining after steel piles are in place

Pound Pile Splices (On plans or ordered) Each Pile Splices (Not on plans and not ordered) Subsidiary Chemical Admixture Subsidiary Driving-Points for Steel Piles*** Each *Cut-off material from shells for cast -in-place concrete piles shall remain the property of the Contractor, and will not be measured for payment. No separate measurement will be made for reinforcing steel, excavation, drilling, cleaning of drilled holes, drilling fluids, sealing materials, concrete, required casing, and other items required to complete the work. **Steel pile cut-offs shall become the property of the Department. Extra pile lengths ordered for the purposes stated in 3.1.1.1 will not be included in this quantity. ***No allowance will be made under furnishing or driving steel piles for the weight of driving -points. Basis of Payment

5.1The accepted quantities of bearing piles and related items will be paid for at the Item Bid Price per unit of measurement

complete in place.

5.2One-half the price bid for pile driving equipment will be paid when pile driving operations have started and the balance paid

when the pile driving work has been completed.

5.3When test piles are ordered, they will be paid for on the same basis as the other piles unless there are no other piles driven

and there is no item for pile driving equipment in the p roposal, in which case the test piles will be paid as provided for in 109.04, consideration being given to the cost of transporting the driving equipment to and from the site of the work.

5.4Work ordered under 3.1.6 be paid as provided for in 109.04 except that no payment will be made for such work when the

obstruction was placed there by the Contractor under the Contract.

5.5Steel pile cut-off material will be paid for at the invoice costs plus 15 percent.

Pay items and units: 510.1_ Pile Driving Equipment Unit 510.2_ Pile Loading Tests Each

510.41_ Furnishing Precast Concrete Bearing Piles Linear Foot

510.42_ Driving Precast Concrete Bearing Piles Linear Foot

510.5_ Cast-in-Place Concrete Bearing Piles Linear Foot

510.61_ Furnishing and Driving Steel Bearing Piles Pound

510.65_ Driving-Points for Steel Bearing Piles Each

510.9____ Pile Splices Each

New Hampshire Department of Transportation Standard Specifications – 2016

BRIDGE DECK REPAIRS Description

This work shall consist of the preparation for repairs of concrete bridge deck including the removal of bituminous materials,

the removal of unsound concrete from the existing deck to assure proper repair, and the disposal of all materials removed. Equipment

The equipment used for pavement and concrete removal shall be subject to approval of the Engineer and shall comply with

the following: 2.1.1 Bituminous pavement removal. 2.1.1.1 The pavement removal may be performed with planers, backhoes, loaders, or other approved mechanical equipment. 2.1.2 Bridge deck concrete overlay. 2.1.2.1 Scarifying equipment shall be either a power operated rotary scarifier or a high-pressure waterjet scarifier capable of uniformly scarifying the existing surface to the depth required i n a satisfactory manner. Scarifying equipment shall be fully automated. Power operated rotary scarifier shall be equipped with a short ski, shoe or a similar device attached to the cutter head to limit the depth of cut. The use of multiple impact or vibratory equipment will not be allowed. 2.1.2.2 Sand or water blasting equipment shall be capable of removing rust and loose concrete from the exposed reinforcement and concrete surface. 2.1.3 Bridge deck concrete partial or full depth repairs. 2.1.3.1 Sawing equipment shall be capable of cutting concrete to the specified depth. 2.1.3.2 Power driven hand tools for concrete removal will be permitted with the following restrictions:

the surface of the deck.

reinforcing bar.

achieve the required depth of removal. 2.1.3.3 High-pressure waterjet equipment, either hand held or remote controlled, will be permitted for concrete removal. Construction Requirements

Concrete and pavement shall be removed from each area as shown on the plans or required. Removal areas as shown are

based on Department studies; actual removal areas will be determined by the Engineer. The various classes of removal shall be accomplished according to the following requirements. 3.1.1 When preparation for bridge deck concrete overlay is not specified, the concrete bridge deck pavement removal shall be accomplished with equipment capable of removing the existing bituminous pavement and membrane waterproofing without damaging the top surface of the deck concrete. The preparation of the deck surface prior to placement of new barrier membran e shall include removal of all existing membrane waterproofing and any membrane primer which is not tightly adhered to sound concrete. The Engineer may order sand blasting of a test area of primer to determine its acceptability for leaving in place. Additional preparation of the deck surface shall be as recommended by the manufacturer of the new barrier membrane to be applied. 3.1.2 When preparation for bridge deck concrete overlay is specified, the entire existing concrete deck area shall be uniformly scarified to a minimum depth of 1/4” or as specified on the plans. Removal to a greater depth will be required adjacent to scuppers and expansion joints and elsewhere, as shown on the plans or ordered. All full and partial depth repairs shall be performed prior to the scarification of the entire deck, unless otherwise permitted. 3.1.3 When removal for partial or full depth repairs is specified, the concrete may be removed by chipping or by a combination of scarifying and chipping, except that final chipping, in any case, shall be by use of hand tools. The entire periphery of the partial or full depth removal areas shall be saw cut to a minimum depth of 1”. or to the top of the upper reinforcing steel. Care shall be taken to avoid cutting into any reinforcing bars. Care shall be exercised to prevent stretching or damaging exposed reinforcing steel. 3.1.3.1 Partial depth removal for all concrete within the periphery of the designated removal area shall extend at least to 3/4” below the lower bars of the top reinforcing steel mat, or deeper as required to r emove all unsound concrete. The Engineer may