Pile Driving Inspector Course Module 7: Begin Pile Driving

Transcription

1 Pile Driving Inspector Course October 2018 Pile Driving Inspector Course Release 10, Module 7-1 Release 10 July

2 Learning Outcomes Monitor and verify proper marking of the piles per contract documents and standards Verify & document Contractor compliance with applicable tolerances Monitor, verify and document pile driving operations Identify applicable 455 Specifications October 2018 Pile Driving Inspector Course Release 10, Module 7-2 Release 10 July

3 Inspector s Role Verify Contractor Compliance with Project Plans and Specifications Monitor and Maintain Record of Driving Determine When to Stop Driving October 2018 Pile Driving Inspector Course Release 10, Module 7-3 As discussed earlier, the Inspector has numerous responsibilities throughout the pile driving operations. During pile driving, the Inspector needs to verify compliance with the project Plans and Specifications for pile plan location, axial alignment, monitor and maintain record of the driving and the most important to determine when to stop driving and accept the pile. During the driving of the pile, there are specific duties, such as hammer and pile cushion inspection, together with the recording of the operation, blows, stroke height/pressure, etc. Release 10 July

4 Inspector s Checklist October 2018 Pile Driving Inspector Course Release 10, Module 7-4 Using a checklist might be helpful in the inspection of Pile Driving. A full size version of the checklist is included in the Appendices. Release 10 July

5 Allowable Driving Tolerances General: Meet the tolerances described in this Subarticle for the piles that are free standing without lateral restraint (after the template is removed). After the piles are driven, do not move the piles laterally to force them to be within the specified tolerances, except to move battered piles to overcome the dead load deflections caused by the pile s weight. When this is necessary, submit calculations signed and sealed by a Specialty Engineer that verify the amount of dead load deflection prior to moving any piles. October 2018 Pile Driving Inspector Course Release 10, Module 7-5 Release 10 July

6 Allowable Driving Tolerances Position: Ensure that the final position of the pile head at cut-off elevation is no more than 3 inches, or 1/6 of the diameter of the pile, whichever is less, laterally in the X or Y coordinate from the Plan position indicated in the Plans Axial Alignment: Ensure that the axial alignment of the driven piles does not deviate by more than 1/4 inches per foot from the vertical or batter line indicated in the Plans. October 2018 Pile Driving Inspector Course Release 10, Module 7-6 Release 10 July

7 Allowable Driving Tolerances Elevation: Ensure that the final elevation of the pile head is no more than 1-1/2 inches above, or more than 4 inches below, the elevation shown in the Plans, however in no case shall the pile be embedded less than 8 inches into the cap or footing. For fender piles, cut off piles at the elevation shown in the Plans to a tolerance of plus 0.0 inches to minus 2.0 inches using sawing or other means as approved by the Engineer to provide a smooth level cut. October 2018 Pile Driving Inspector Course Release 10, Module 7-7 Release 10 July

8 Position As Built Pile Location Maximum Allowable Tolerance 3 In Any One Direction Plan Pile Location Maximum Allowable Tolerance 3 In Any One Direction October 2018 Pile Driving Inspector Course Release 10, Module 7-8 This slide illustrates the horizontal position maximum of 3 inches in any direction. tolerance which is a If out of tolerance, notify contractor, document and notify PA. Release 10 July

9 ¼ Axial Alignment October 2018 Pile Driving Inspector Course Release 10, Module 7-9 This slide illustrates the axial alignment tolerance. The maximum deviation allowed from the plan alignment is ¼ inch per foot. If out of tolerance, notify contractor, document and notify PA. Release 10 July

10 Checking Axial Alignment Pile 4 ft. Builders Square positioned level on reference Reference 4 1 October 2018 Pile Driving Inspector Course Release 10, Module 7-10 This slide illustrates one method for checking the axial alignment which is using a 4ft builders square. Release 10 July

11 Elevation No more than 1 ½ above Cutoff Elevation Cutoff Elevation No more than 4 below Cutoff Elevation October 2018 Pile Driving Inspector Course Release 10, Module 7-11 This is an illustration of the vertical elevation tolerance described before. The final pile top of the pile cannot be higher than 1-1/2 above the cutoff elevation of the plans or more than 4 inches below the cutoff elevation shown in the plans Release 10 July

12 Predrilling of Pile Holes Predrilling of Pile Holes: Predrilled pile holes are either starter holes to the depth described in this Subarticle or holes drilled through embankment/fill material down to the natural ground surface at no additional cost to the Department. When using low displacement steel piling such as structural shapes, drive them through the compacted fill without the necessity of drilling holes through the fill except when the requirements for predrilling are shown in the Plans. When using concrete or other high displacement piles, drill pile holes through fill, new or existing, to at least the elevation of the natural ground surface. October 2018 Pile Driving Inspector Course Release 10, Module 7-12 Let us review the predrilling of pile holes specification. The Contractor is not paid for Predrilled Holes. These are up to 10 ft or 20 % of the pile length (whichever is greater) starter holes. Release 10 July

13 Predrilling through Fill Natural Ground is defined as the ground surface prior to any roadway construction Predrilled Hole Existing Embankment Natural Ground Surface October 2018 Pile Driving Inspector Course Release 10, Module 7-13 This illustrates what natural ground means in the predrilling specification. For concrete piles or other displacement piles, predrilling holes should be taken to at least the natural ground level. Release 10 July

14 Predrilling of Pile Holes: (cont d) Use the range of drill diameters listed below for square concrete piles. 12 inch square piles 15 to 17 inches 14 inch square piles 18 to 20 inches 18 inch square piles 22 to 26 inches 20 inch square piles 24 to 29 inches 24 inch square piles 30 to 34 inches 30 inch square piles 36 to 43 inches October 2018 Pile Driving Inspector Course Release 10, Module 7-14 This slide indicates the required drill diameters for predrilled holes for concrete piles. It is important that the Inspector recognize that whatever depth of predrilled hole was used in the Test Pile program is the depth used in production piles. Therefore, if 6 foot predrilled holes were used in the Test pile program and the Contractor wants to do 20 foot predrilled holes during production, this is not permitted. The Inspector should inform the Contractor it is not permitted, contact the PA and document the depth of hole predrilled. Release 10 July

15 Predrilling of Pile Holes: (cont d) For other pile sizes, use the diameter of the drills shown in the Plans or approved by the Engineer. Accurately drill the pile holes with the hole centered over the Plan location of the piling. Maintain the location and vertical alignment within the tolerances allowed for the piling. For predrilled holes required through rock or other hard (i.e. debris, obstructions, etc.) materials that may damage the pile during installation, predrill hole diameters approximately 2 inches larger than the largest dimension across the pile cross-section. Fill the annular space around the piles as described in with clean A-3 sand or sand meeting the requirements of October 2018 Pile Driving Inspector Course Release 10, Module 7-15 Release 10 July

16 Predrilling of Pile Holes: (cont d) In the setting of permanent and test piling, the Contractor may initially predrill holes to a depth up to 10 feet or 20% of the pile length whichever is greater, unless otherwise shown in the Plans. Where installing piles in compacted fill, predrill the holes to the elevation of the natural ground surface. With prior written authorization from the Engineer, the Contractor may predrill holes to greater depths to minimize the effects of vibrations on existing structures adjacent to the work and/or for other reasons the Contractor proposes. October 2018 Pile Driving Inspector Course Release 10, Module 7-16 Note: the bottom of a Pre-drilled hole is NOT the bottom of an Excavation. The bottom of the excavation is the bottom of the footing or pile cap excavation. Release 10 July

17 Preformed Pile Holes Description: Preformed pile holes serve as a penetration aid when all other pile installation methods fail to produce the desired penetration and when authorized by the Engineer to minimize the effects of vibrations on adjacent structures. Preformed pile holes are necessary when the presence of rock or strong strata of soils will not permit the installation of piles to the desired penetration by driving or a combination of jetting and driving, when determined necessary by the Engineer, or when authorized by the Engineer to minimize the effects of vibrations on adjacent existing structures. The Engineer may require preformed holes for any type of pile. Drive all piles installed in preformed pile holes to determine that the bearing requirements have been met. October 2018 Pile Driving Inspector Course Release 10, Module 7-17 Preforming of Holes is generally called for in the Plans and the Contractor is paid for these holes. Remember that Preforming depths are typically shown in the Pile Data Table and are given as an Elevation. Preformed Hole Depth, for recording purposes, is the depth or length of Preformed Hole drilled by the Contractor. Therefore, the Inspector needs to verify that the preformed Hole was drilled to the elevation specified and then record that length for pay purposes. Release 10 July

18 Preformed Pile Holes Description: (cont d) For preformed holes which are required through material that caves during driving to the extent that the preformed hole does not serve its intended purpose, case the hole from the surface through caving material. After installing the pile to the bottom of the casing, remove the casings unless shown otherwise in the Plans. Determine bearing of the pile after removing the casing unless shown otherwise in the Plans. October 2018 Pile Driving Inspector Course Release 10, Module 7-18 Note: Keep in mind that the bottom of a Preformed hole is NOT the bottom of an Excavation. The bottom of the excavation in the specs refers to the bottom of the excavation for the construction of the pile cap or footing. Release 10 July

19 Preformed Pile Holes Description: (cont d) Fill all voids between the pile and soil remaining after driving through preformed holes with clean A-3 sand or sand meeting the requirements of , after the pile has achieved the required minimum tip elevation, unless grouting of preformed pile holes is shown in the Plans. If pile driving is interrupted during sand placement, drive the pile at least 20 additional blows after filling all of the voids between the pile and soil with sand at no additional cost to the Department. October 2018 Pile Driving Inspector Course Release 10, Module 7-19 Release 10 July

20 Preformed Pile Holes Provisions for Use of Preformed Pile Holes: The Department generally anticipates the necessity for preformed pile holes and includes directions in the Contract Documents. The Department will pay for preformed pile holes when the Contractor establishes that the required results cannot be obtained when driving the load bearing piles with specified driving equipment, or if jetting is allowed, while jetting the piles and then driving or while jetting the piles during driving. October 2018 Pile Driving Inspector Course Release 10, Module 7-20 Release 10 July

21 Preformed Pile Holes Conditions Under Which Payment Will Be Made: The Department will make payment for preformed pile holes shown in the Plans, required by the Engineer or where the Contractor demonstrates that such work is necessary to achieve the required penetration without overstressing the pile. The Department considers, but does not limit to, the following conditions as reasons for preformed pile holes: 1. Inability to drive piles to the required penetration with driving and jetting equipment. 2. To penetrate a hard layer or layers of rock or strong stratum that the Engineer considers not sufficiently thick to support the structure. October 2018 Pile Driving Inspector Course Release 10, Module 7-21 Release 10 July

22 Preformed Pile Holes Conditions Under Which Payment Will Be Made: (cont d) 3. To obtain greater penetration into dense (strong) material and into dense material containing holes, cavities or unstable soft layers. 4. To obtain penetration into a stratum in which it is desired to found the structure. 5. To minimize the effects of vibrations or heave on adjacent existing structures. 6. To minimize the effects of ground heave on adjacent piles. October 2018 Pile Driving Inspector Course Release 10, Module 7-22 Release 10 July

23 Preformed Pile Holes Construction Methods: Construct preformed pile holes by drilling, or driving and withdrawing a suitable punch or chisel at the locations of the piles. Construct a hole that is equal to or slightly greater than the largest pile dimension for the entire length of the hole and of sufficient depth to obtain the required penetration. Carefully form the preformed hole by using a drill or punch guided by a template or other suitable device, and do not exceed the minimum dimensions necessary to achieve the required penetration of the pile. October 2018 Pile Driving Inspector Course Release 10, Module 7-23 The specifications require the contractor to construct a hole that is equal to or slightly greater than the largest pile dimension for the entire length of the hole and of sufficient depth to obtain the required penetration. Release 10 July

24 Preformed Pile Holes Construction Methods: (cont d) When the Plans call for grouting the preformed pile holes, provide a minimum pile hole dimension 2 inches larger than the largest pile dimension. Construct the holes at the Plan position of the pile and the tolerances in location, and ensure the hole is straight and that the batter is the same as specified for the pile. Loose material may remain in the preformed pile hole if the conditions in are satisfied. October 2018 Pile Driving Inspector Course Release 10, Module 7-24 Release 10 July

25 Preformed Pile Holes October 2018 Pile Driving Inspector Course Release 10, Module 7-25 We will see now a short video of a pile being stuck in a preformed/predrilled hole. Note this one is just gliding in, very easy. Click brings the video. Release 10 July

26 Preformed Pile Holes Grouting of Pile Holes: Clean and grout preformed pile holes for bearing piles, when the Plans require grouting after driving. Use grout that meets the requirements of to and has a minimum compressive strength of 3,000 psi at 28 days or as specified in the Plans. Prepare cylinders and perform QC testing in accordance with LOT size and verification will be in accordance with Pump the grout through three or more grout pipes initially placed at the bottom of the preformed hole. The Contractor may raise the grout pipes when necessary to prevent clogging and to complete the grouting operations. October 2018 Pile Driving Inspector Course Release 10, Module 7-26 Release 10 July

27 Preformed Pile Holes Grouting of Pile Holes (cont d): Maintain the grout pipes below the surface of the previously placed grout. Continue grouting until the grout reaches the ground surface all around the pile. Provide divers to monitor grouting operations when the water depth is such that it is impractical to monitor from the ground surface. When grouting is shown in the Plans, include the cost in the price for piles. In the event that the Engineer determines the Contractor must grout and the required grouting is not shown in the Plans, the Department will pay for the grouting work as Unforeseeable Work. October 2018 Pile Driving Inspector Course Release 10, Module 7-27 Release 10 July

28 Learning Outcome Which, Predrilling or Preforming, is the Contractor Paid for accomplishing? The tolerance for plan position is. A. 3 inches B. 4 inches C. 5 inches D. 6 inches October 2018 Pile Driving Inspector Course Release 10, Module 7-28 As a review, please answer the following exercises: Which one, Predrilling or Preforming, is the Contractor paid for accomplishing? The tolerance for plan position is Release 10 October

29 Learning Outcome For each of the following situations, answer which holes, Predrilled holes or Preformed holes, are to have hole diameters approximately 2 inches larger than the largest dimension across the pile crosssection? a. When drilling through rock or other hard materials? b. When plans call for grouting the preformed holes? The tolerance for axial alignment for driven piles is. A. 2 inches/ft. B. 1 inch/ft. C. ½ inch/ft. D. ¼ inch/ft. October 2018 Pile Driving Inspector Course Release 10, Module 7-29 Answer the questions asked in the slide. In the first question, there are two situations. For each situation answer when are Predrilled holes and Preformed required to have hole diameters approximately 2 inches larger than the largest dimension across the pile cross-section. The tolerance for axial alignment is Release 10 October

30 Verify Marking of the Piles English mark in 1 ft. intervals October 2018 Pile Driving Inspector Course Release 10, Module 7-30 Generally, projects are designed in English units. These will require a blow count criteria in blows per foot, therefore the pile should be marked in 1 foot intervals. The Contractor is responsible for marking the piles. The Inspector needs to double check the Contractor s marks. Inch marks come in handy as a reference should real hard driving be encountered. When inspectors suspect it is possible to obtain 20 blows per inch or more, they typically stop to mark a particular increment in inches to be able to stop within 1 or 2 inches in practical refusal. The idea is not to overdrive the piles. This short video shows a contractor employee marking a piles. Release 10 July

31 Verify Marking of the Piles October 2018 Pile Driving Inspector Course Release 10, Module 7-31 On the left is a marked pipe pile being driven, while on the right is an H pile, marked in feet and inches, being driven. It is important to understand that a pipe pile may rotate. Additional marks may be necessary in order to make them visible for inspection purposes. Remember to check the Contractor s marking of the pile. Release 10 July

32 455-6 Timber Piling Cutting Off: Saw off the tops of all timber piles at the elevation indicated in the Plans. Saw off piles which support timber caps to the exact plane of the superimposed structure so that they exactly fit. Withdraw and replace broken, split, or misplaced piles Build-ups: The Engineer will not permit splices or build-ups for timber piles. Extract piles driven below Plan elevation and drive a longer pile. October 2018 Pile Driving Inspector Course Release 10, Module 7-32 This slide indicates that splices or build-ups are not allowed for timber piles. Piles with insufficient bearing need to be extracted and a longer pile must be driven. Release 10 July

33 455-7 Prestressed Concrete Piling General: Provide prestressed concrete piles that are manufactured, cured, and driven in accordance with the Contract Documents. Provide piles full length without splices when transported by barge or the pile length is less than or equal to 120 feet. When piles are transported by truck and the pile length exceeds 120 feet but is less than the maximum length for a three point pick-up according to Standard Plans, Index No , and splicing is desired, provide minimal splices. Include the cost of the splices in the cost of the pile. October 2018 Pile Driving Inspector Course Release 10, Module 7-33 Release 10 July

34 455-7 Prestressed Concrete Piling Extensions and Build-ups Used to Increase Production Lengths: General: Where splices, extensions and build-ups for concrete piles are necessary, construct them in accordance with Standard Plans, Index No These requirements are not applicable to specially designed piling. Make splices for special pile designs as shown in the Plans. October 2018 Pile Driving Inspector Course Release 10, Module 7-34 Release 10 July

35 455-7 Prestressed Concrete Piling-Build Up October 2018 Pile Driving Inspector Course Release 10, Module 7-35 Illustrated here is what a normally known build-up looks like. According Standard Plans, Index , build-ups can be can be up to 5 ft long. The term splice or extensions is reserved for the longer, precast extensions that are added to the original pile. The longer splices require prefabricated concrete sections that may be prestressed or not, depending whether they are drivable splices and also depending on the length. Release 10 July

36 455-7 Prestressed Concrete Piling-Splices October 2018 Pile Driving Inspector Course Release 10, Module 7-36 Illustrated here are the splices, as per Standard Plans, Index The longer splices require prefabricated concrete sections that may be prestressed or not, depending whether they are drivable splices and also depending on the length. Release 10 July

37 455-7 Prestressed Concrete Piling Extensions to be Driven or Those 21 feet or Longer: Construct extensions to be driven or extensions 21 feet or longer in length in accordance with the details shown in the Plans and in a manner including the requirements, sequences, and procedures outlined below: October 2018 Pile Driving Inspector Course Release 10, Module 7-37 Let us review what the specs say about pile extensions for concrete piles, when these are to be driven or are 21 feet or longer. They need to be prestressed concrete sections. These specifications apply to any section that needs be driven and for sections 21 feet or longer whether they need to be driven or not. Release 10 July

38 Constructing Splice- Concrete Piling October 2018 Pile Driving Inspector Course Release 10, Module 7-38 The following slides will show the sequence in the making of a splice for a concrete pile. This is a pre-fabricated splice that just arrived to the site. The dowels of this splice will be used to fabricate a template to drill the holes in the pile head. Release 10 July

39 Constructing Splice- Concrete Piling October 2018 Pile Driving Inspector Course Release 10, Module 7-39 This picture shows holes being drilled in the template after the hole location has been marked. Release 10 July

40 Constructing Splice- Concrete Piling October 2018 Pile Driving Inspector Course Release 10, Module 7-40 In this picture the template is being checked with the splice rebars to make sure the template was accurately drilled. Release 10 July

41 Constructing Splice- Concrete Piling October 2018 Pile Driving Inspector Course Release 10, Module 7-41 This picture illustrates the template and forms being placed at top of the pile. Release 10 July

42 Constructing Splice- Concrete Piling 1. Cast a splice section in accordance with Section 450 with the dowel steel in the correct position and alignment. 2. Drill dowel holes using an approved steel template that will position and align the drill bit during drilling. Drill holes a minimum of 2 inches deeper than the length of the dowel to be inserted. 3. Clean the drilled dowel holes by inserting a high pressure air hose to the bottom of the hole and blowing the hole clean from the bottom upward. Eliminate any oil, dust, water, and other deleterious materials from the holes and the concrete surfaces to be joined. 4. Place forms around joints between the pile sections. October 2018 Pile Driving Inspector Course Release 10, Module 7-42 Note: section 450 is the Department s section regarding precast prestressed concrete construction. These splices need to be prefabricated prestressed concrete sections. Release 10 July

43 Constructing Splice- Concrete Piling October 2018 Pile Driving Inspector Course Release 10, Module 7-43 This picture shows the top of the pile after being drilled and cleaned. Release 10 July

44 Constructing Splice- Concrete Piling 5. Mix the adhesive components in accordance with the manufacturer s directions. Do not mix sand or any other filler material with the epoxy components unless it is prepackaged by the manufacturer for this specific purpose. Use adhesives meeting the requirements of Section 926 for Type AB epoxy compounds. 6. After ensuring that all concrete surfaces are dry, fill the dowel holes with the adhesive material. October 2018 Pile Driving Inspector Course Release 10, Module 7-44 Release 10 July

45 Constructing Splice- Concrete Piling October 2018 Pile Driving Inspector Course Release 10, Module 7-45 This picture shows the adhesive being poured into the dowel holes Release 10 July

46 Constructing Splice- Concrete Piling 7. Insert the dowels of the spliced section into the adhesive filled holes of the bottom section and position the spliced section so that the axes of the two sections are in concentric alignment and the ends of the abutting sections are spaced 1/2 inches apart. The Contractor may use small steel spacers of the required thickness provided they have 3 inches or more of cover after completing the splice. Fill the space between the abutting sections completely with the adhesive. October 2018 Pile Driving Inspector Course Release 10, Module 7-46 Release 10 July

47 Constructing Splice- Concrete Piling October 2018 Pile Driving Inspector Course Release 10, Module 7-47 This picture shows the spliced after being inserted into the original pile. Note the adhesive that has been applied. Release 10 July

48 Constructing Splice- Concrete Piling 8. Secure the spliced sections in alignment until the adhesive is cured in accordance with the manufacturer s directions for the time appropriate with the prevailing ambient temperatures. Do not utilize the crane to secure the pile extension during the adhesive cure time. Utilize alignment braces to maintain the proper pile alignment during the epoxy cure time. 9. After curing is completed, remove alignment braces and forms and clean and dress the spliced area to match the pile dimensions. October 2018 Pile Driving Inspector Course Release 10, Module 7-48 Release 10 July

49 Constructing Splice- Concrete Piling October 2018 Pile Driving Inspector Course Release 10, Module 7-49 This slide shows how the alignment of the spliced sections is verified. Release 10 July

50 Constructing Splice- Concrete Piling October 2018 Pile Driving Inspector Course Release 10, Module 7-50 This picture shows a splice just being completed. Release 10 July

51 455-7 Prestressed Concrete Piling Precast Reinforced Non-Drivable Build-ups less than 21 feet: Construct precast reinforced non-drivable build-ups less than 21 feet in accordance with the requirements of this Subarticle, Section 346, and Section 400. Provide the same material for the form surfaces for precast build-ups as was used to form the prestressed piles. Use concrete of the same mix as used in the prestressed pile and dimension the cross-section the same as piling being built up. Install build-ups as specified in (2) through (9). Apply to the buildups the same surface treatment or sealant applied to the prestressed piles. October 2018 Pile Driving Inspector Course Release 10, Module 7-51 Regarding non drivable splices shorter than 21 ft, the following specification applies The process is similar to building the prestressed concrete splice that we covered earlier, except that since a prestressed section is not required then the item (a) from the previous process is not required. Release 10 July

52 455-7 Prestressed Concrete Piling Pre-Planned Splices: Construct splices in accordance with the dowel splice method contained in the Standard Plans or using proprietary splices which are listed on the Department s Approved Product List (APL). Splice test piles in the same manner as the production piles. Include in the pile installation plan, the chosen method of splicing and the approximate locations of the splice. October 2018 Pile Driving Inspector Course Release 10, Module 7-52 Release 10 July

53 455-7 Prestressed Concrete Piling Pre-Planned Splices: (cont d) Generally, place the splice at approximately the midpoint between the estimated pile tip and the ground surface, considering scour if applicable. Stagger the splice location between adjacent piles by a minimum of 10 feet. Obtain the Engineer s approval prior to constructing any pile sections. Construct piles which are to be spliced using the dowel splice with preformed dowel holes in the bottom section and embedded dowels in the upper section. October 2018 Pile Driving Inspector Course Release 10, Module 7-53 Release 10 July

54 455-8 Steel Piling Pile Splices: Order and use the full authorized pile length where practicable. Do not splice to obtain authorized lengths less than 40 feet except when shown in the Plans. Locate all splices in the authorized pile length in portions of the pile expected to be at least 15 feet below the final ground surface after driving. When it is not practicable to provide authorized pile lengths longer than 40 feet in a single length, use no more than one field splice per additional 40 feet of authorized pile length. Shop splices may be used to join single lengths of pile which are at least 20 feet in length. One shorter segment of pile may be used to achieve the authorized pile length when needed. October 2018 Pile Driving Inspector Course Release 10, Module 7-54 Release 10 July

55 455-8 Steel Piling Pile Splices: (cont d) Where the pile length authorized is not sufficient to obtain the required bearing value or penetration, order an additional length of pile and splice it to the original length. Make all splices in accordance with details shown in the Plans and in compliance with the general requirements of AWS D1.1 or American Petroleum Institute Specification 5L (API 5L). October 2018 Pile Driving Inspector Course Release 10, Module 7-55 Release 10 July

56 Splice- Steel Pile October 2018 Pile Driving Inspector Course Release 10, Module 7-56 This picture illustrates a splice on a steel pile. Release 10 July

57 455-8 Steel Piling Filling Pipe Piles: When required by the Plans, fill pipe piles with the specified materials. Use clean concrete sands and concrete meeting the requirements of Section 346. Place concrete in pipes containing water using methods in accordance with with modified tremie and pump line sizes. Concrete may be placed directly into pipes which are dry. Construct and place reinforcement cages in accordance with except the minimum number of spacers per level is three. Reinforcement cages may be installed before concrete placement or after concrete placement is completed if proper alignment and position is obtainable. October 2018 Pile Driving Inspector Course Release 10, Module 7-57 Release 10 July

58 Penetration Penetration Requirements: Measure the penetration of piles from the elevation of natural ground, scour elevation shown in the Plans, or the bottom of excavation, whichever is lower. When the Contract Documents show a minimum pile tip elevation, drive the tip of the pile to this minimum elevation. The Engineer will accept the bearing of a pile only if the Contractor achieves the required bearing when the tip of the pile is at or below the specified minimum tip elevation and below the bottom of the preformed or predrilled pile hole. October 2018 Pile Driving Inspector Course Release 10, Module 7-58 Release 10 July

59 Penetration October 2018 Pile Driving Inspector Course Release 10, Module 7-59 Penetration is measured as the difference between the lowest of these three elevations and the tip of the pile. NOTE- The bottom of predrilled or preformed holes is not considered the bottom of an excavation. Release 10 July

60 Penetration Penetration Requirements: (cont d) When the Plans do not show a minimum tip elevation, ensure that the penetration is at least 10 feet into firm bearing material or at least 20 feet into soft material unless otherwise permitted by the Engineer. If a scour elevation is shown in the Plans, achieve this penetration below the scour elevation. The Engineer may accept a penetration between 15 feet and 20 feet when there is an accumulation of five consecutive feet or more of firm bearing material. October 2018 Pile Driving Inspector Course Release 10, Module 7-60 Release 10 July

61 Penetration Penetration Requirements: (cont d) Firm bearing material is any material offering a driving resistance greater than or equal to 30 tons per square foot of gross pile area as determined by the Dynamic Load Testing ( ). Soft material is any material offering less than these resistances. The gross pile area is the actual pile tip crosssectional area for solid concrete piles, the product of the width and depth for H piles, and the area within the outside perimeter for pipe piles and voided concrete piles. October 2018 Pile Driving Inspector Course Release 10, Module 7-61 Release 10 July

62 Penetration Penetration Requirements: (cont d) Do not drive piles beyond practical refusal. To meet the requirements in this Subarticle, provide penetration aids, such as jetting or preformed pile holes, when piles cannot be driven to the required penetration without reaching practical refusal. If the Contractor encounters unforeseeable, isolated obstructions that the Contractor cannot practically penetrate by driving, jetting, or preformed pile holes, and the Contractor must remove the pile to obtain the required pile penetration, the Department will pay the costs for such removal as Unforeseeable Work. October 2018 Pile Driving Inspector Course Release 10, Module 7-62 More on Penetration requirements: Piles shall not be driven beyond practical refusal in order to get the minimum tip elevation or the penetration requirements. Please remember that practical refusal is not 240 blows per foot, but 20 blows per inch. Release 10 July

63 Bearing Requirements General: For foundations requiring 100% dynamic testing of production piles, the Engineer may accept a driven pile when the pile has achieved minimum penetration and the minimum required bearing for 6 inches of consecutive driving, or when the minimum penetration is achieved, driving has reached practical refusal in firm material and the bearing capacity is obtained in all the refusal blows. October 2018 Pile Driving Inspector Course Release 10, Module 7-63 Here is where the specs starts talking about how the piles will be accepted. Increasing blowcount should not be a result of a change in fuel settings. Blowcounts may drop with an increase in stroke height (OED hammers). Though the blow count is decreasing, with an increased stroke height, since we are putting more energy into the pile, we may be actually getting similar or even higher capacity. Release 10 July

64 Bearing Requirements General: (cont d) For foundations not requiring 100% dynamic testing of production piles, the Engineer may accept a driven pile when the pile has achieved minimum penetration, the blow count is generally the same or increasing and the minimum required bearing capacity obtained for 24 inches of consecutive driving. At the discretion of the Engineer, the driven pile may be accepted when the minimum penetration is achieved and driving has reached practical refusal in firm material. October 2018 Pile Driving Inspector Course Release 10, Module 7-64 Here is where the specs starts talking about how the piles will be accepted. Increasing blowcount should not be a result of a change in fuel settings. Blowcounts may drop with an increase in stroke height (OED hammers). Though the blow count is decreasing, with an increased stroke height, since we are putting more energy into the pile, we may be actually getting similar or even higher capacity. Release 10 July

65 Data Recording The Pile Driving Record, which includes: Hammer blows for each interval Stroke Height or bounce chamber pressure for each interval Making appropriate notes concerning driving operations October 2018 Pile Driving Inspector Course Release 10, Module 7-65 A Pile Driving Record is maintained by the Inspector. The Pile Driving Record includes information such as hammer blows for each interval, stroke height or bounce chamber pressure for each interval and notes of all the events that happen during the pile driving. Release 10 July

66 Data Recording October 2018 Pile Driving Inspector Course Release 10, Module 7-66 A video will be presented now that illustrates the use of saximeter during the driving of a pile with an open End Diesel Hammer. You will notice on this video how the stroke changes from blow to blow. This is very typical of Diesel hammers. Note also how average values of stroke are shown once you hit the avg key. In the top row labeled as LAST the saximeter displays the average values of stroke, blows per minute and number of blows observed in the previous increment. In the second row labeled NOW you will see the strokes, blow per minute and the blow number of the increment you are currently in.. (Click brings in close-up video of the Saximeter being used during pile driving.) Release 10 July

67 Check Hammer Settings October 2018 Pile Driving Inspector Course Release 10, Module 7-67 The Driving criteria Letter may provide a start of driving stroke height, fuel setting or pressure. This is quite common when dealing with concrete piles, especially if easy or soft driving initially is anticipated. Soft or little resistance at the tip and a big stroke height can result in excess tension in a concrete pile and damage the tip. In these cases, a reduced setting will be specified in the Driving Criteria Letter, to minimize the potential for pile damage, especially with concrete piles. As shown in this letter sample is a provision in case the blow count drops. In other words, in case the soil capacity drops. The driving criteria latter may require that the stroke be reduced to control stresses as it is the case in the sample letter shown here. Remember to document all fuel settings and changes that happens during the actual driving of the pile. Release 10 July

68 Fuel Settings- OED 4-setting fuel pump for Openend Diesel hammer (lanyards) October 2018 Pile Driving Inspector Course Release 10, Module 7-68 Shown here is a fixed four step fuel pump on a Delmag hammer. Generally open end diesel hammers are equipped with 4 fuel settings that enable the operator to control the stroke height. Fuel setting #1 is the lowest, and thereby produces the least combustion, hence the lowest stroke height. Typically, the higher the fuel setting the higher the stroke. A lanyard is connected to the pump and adjustments made by someone on the ground pulling the lanyard. With these hammers, the fuel setting directly affects the stroke height: the higher the fuel setting the bigger the combustion, hence a higher stroke height. Release 10 July

69 Fuel Settings- OED Adjustable pressure pump for changing fuel setting October 2018 Pile Driving Inspector Course Release 10, Module 7-69 Shown here is an adjustable pressure pump for fuel setting on an ICE hammer. Closed end diesel, air/steam and hydraulic hammers are pressure operated and allow for a more precise setting of the hammer energy delivered than the open end diesel or drop hammer. Release 10 July

70 Fuel Settings- OED October 2018 Pile Driving Inspector Course Release 10, Module 7-70 The following video will show a technician setting the fuel setting with a pump Click (brings video.) Release 10 July

71 Stroke Height Setting Slide Bar- 2 Stroke Height Settings for Air Hammer October 2018 Pile Driving Inspector Course Release 10, Module 7-71 The various types of hammers have various ways to control the stroke. With drop hammers the stroke height is controlled by the operator lifting the weight. Open end diesel stroke height is a function of the fuel setting and resistance to driving, so in a sense is not really set. In the case of air hammers, the stroke height can be set for providing a constant stroke through the means of a slide bar. The slide bar generally has two cogs for setting either a full stroke (typically 4 ft. or greater) and a short stroke (typically ½ the full stroke but generally no less than 2 ft.). Release 10 July

72 Auxiliary Equipment October 2018 Pile Driving Inspector Course Release 10, Module 7-72 This slide shows the control unit for a double acting BSP hydraulic hammer. It also includes a device that measures the impact energy of the hammer, by measuring the impact velocity of the hammer at the point of impact of the ram. The equivalent stroke is also determined and displayed based on the velocity and energy measurement. Release 10 July

73 Auxiliary Equipment October 2018 Pile Driving Inspector Course Release 10, Module 7-73 For closed end diesel hammers, the pressure is displayed on the Bounce Chamber pressure gauge. With these systems, the Inspector depresses the panel button, typically with their foot, for approx. 10 seconds, during each increment, and records the average pressure being displayed during that time. Don t forget to measure the hose since the equivalent energy depends on the length of the hose. Release 10 July

74 Auxiliary Equipment Bounce Chamber Pressure Gauge- Closed-end Diesel October 2018 Pile Driving Inspector Course Release 10, Module 7-74 Here is a typical bounce chamber pressure versus equivalent energy for a closed end diesel hammer. Note how there are different curves depending on the length of the hose. Release 10 July

75 Common Problems- OED Common Problems Indicators Water in fuel Fuel lines clogged Fuel pump malfunctioning Fuel injectors malfunctioning Oil low Oil pump malfunctioning Water in combustion chamber Piston rings worn Tripping device broken Over heating Hollow sound, white smoke No smoke or little gray smoke Inconsistent ram strokes, little gray smoke or black smoke Inconsistent ram strokes, little gray smoke or black smoke Blows per minute rate is lower than specified Blows per minute rate is lower than specified Hollow sound, white smoke Low strokes Pawl does not engage piston Pawl engages but doesn't lift piston Paint and oil on cooling fins start to burn/sound changes October 2018 Pile Driving Inspector Course Release 10, Module 7-75 This slide shows typical problems and indicators on Diesel hammers. Release 10 July

76 Common Problems- Closed-end Diesel Common Problems Indicators Water in fuel Fuel lines clogged Fuel pump malfunctioning Fuel injectors malfunctioning Oil low Oil pump malfunctioning Water in combustion chamber Piston rings worn Tripping device broken Over heating Oil build up in bounce chamber Hollow sound, white smoke No smoke or little gray smoke Inconsistent ram strokes, little gray smoke or black smoke Inconsistent ram strokes, little gray smoke or black smoke Blows per minute rate is lower than specified Blows per minute rate is lower than specified Hollow sound, white smoke Low strokes Pawl does not engage piston Pawl engages but doesn't lift piston Paint and oil on cooling fins start to burn/sound changes Not visible from exterior October 2018 Pile Driving Inspector Course Release 10, Module 7-76 Discuss common problems and the indicators the Inspector can watch for. Release 10 July

77 Common Problems Common Problems- Air/Steam Indicators Air trip mechanism or hammer malfunctioning Cushion stack height incorrect (affects timing of trip mechanism air valve) Compressor not supplying correct pressure & volume of air to hammer Air supply lines either kinked or tangled in leads, boom, or other Moisture in air ices up hammer erratic operation rates or air valve sticking open or closed erratic operation rates blows per minute rate is varying either faster or slower than the manufacturer specified visually evident ice crystals exiting exhaust ports of hammer Lack of lubricant in air supply lines erratic operation rates Packing around air chest worn ram raises slowly- blows/minute rate slower than specified allowing air blow by by manufacturer- air leaking around piston shaft & air chest Nylon slide bar worn visually evident Ram columns insufficiently greased visually evident October 2018 Pile Driving Inspector Course Release 10, Module 7-77 This slide shows common problems and indicators the Inspector for air hammers. Release 10 July

78 Common Problems- Hydraulic Common Problems Hoses getting caught in leads Fittings leaking Electrical connections Sensors Indicators visually evident hydraulic fluid leaking erratic performance erratic performance October 2018 Pile Driving Inspector Course Release 10, Module 7-78 Here are some common problems and indicators on hydraulic hammers Release 10 July

79 Cushions & Pile Helmet Capblock: Maintain capblocks in good condition, and replace them when charred, melted, or otherwise significantly deteriorated. The Engineer will inspect the capblock before driving begins and weekly or at appropriate intervals determined by the Engineer based on field trial. Replace or repair any capblock which loses more than 25% of its original thickness, in accordance with the manufacturer s instructions, before permitting further driving. October 2018 Pile Driving Inspector Course Release 10, Module 7-79 Release 10 July

80 Check Hammer Cushions The Driving Criteria Letter may specify a different inspection schedule. The above pile driving criteria are based on a hammer driving system consisting of an ICE Model 60-S, single-acting, diesel hammer with a hammer cushion comprised of 0.5 inches of aluminum and 2 inches of blue nylon. Hammer cushions should be inspected on weekly, or appropriate intervals and maintained in accordance with Preforming for the production piles should be conducted in the same manner as the test pile program. If there is a change in the driving system for the piles or the preforming depth and/or techniques, notify the Engineer so new driving criteria can be determined. October 2018 Pile Driving Inspector Course Release 10, Module 7-80 The Inspector should check the Driving Criteria Letter as it may specify a different inspection schedule than the standard specifications. Release 10 July

81 Check Hammer Cushions October 2018 Pile Driving Inspector Course Release 10, Module 7-81 This slide shows a damaged hammer cushion that must be replaced. Release 10 July

82 Check Hammer Cushions October 2018 Pile Driving Inspector Course Release 10, Module 7-82 Here is another hammer cushion that must be replaced Release 10 July

83 Check Hammer Cushions October 2018 Pile Driving Inspector Course Release 10, Module 7-83 Here is another hammer cushion that must be replaced Release 10 July

84 Cushions & Pile Helmet Pile Cushion:...Maintain pile cushions in good condition and replace them when charred, splintered, excessively compressed, or otherwise deteriorated to the point it will not protect the pile against overstressing in tension or compression. Protect cushions from the weather, and keep them dry. Do not soak the cushions in any liquid. Replace the pile cushion, if during the driving of any pile, the cushion is either compressed more than one-half the original thickness, begins to burn, or as directed by the Engineer after field performance... October 2018 Pile Driving Inspector Course Release 10, Module 7-84 Release 10 July

85 Cushions & Pile Helmet Pile Cushion: (cont d) Provide a new cushion for each pile unless approved otherwise by the Engineer after satisfactory field trial. Reuse pile cushions in good condition to perform all set-checks and redrives. Use the same cushion to perform the set-check or redrive as was used during the initial driving, unless this cushion is unacceptable due to deterioration, in which case use a similar cushion. October 2018 Pile Driving Inspector Course Release 10, Module 7-85 Release 10 July

86 Check Pile Cushion October 2018 Pile Driving Inspector Course Release 10, Module 7-86 The Inspector should check the Driving Criteria Letter as it may specify a different inspection schedule than the standard specifications. Release 10 July

87 Check Pile Cushion Question 1: Why might you want a new pile cushion at the start of each pile? Question 2: Would you want to use a new cushion for set-checks/re-strikes? October 2018 Pile Driving Inspector Course Release 10, Module 7-87 Release 10 July

88 Check Pile Cushion Question 1: Why might you want a new pile cushion at the start of each pile? This replicates the Test Pile Program and provides for consistency. Question 2: Would you want to use a new cushion for set-checks/re-strikes? NO- New cushions compress, so you don t want a new one here. Will throw the blow count out of whack. October 2018 Pile Driving Inspector Course Release 10, Module 7-88 Generally, unless it needed to be replaced, the pile cushion being used when driving was stopped is the one to use. Release 10 July

89 Check Pile Cushion October 2018 Pile Driving Inspector Course Release 10, Module 7-89 This picture compares a new cushion with a compressed cushion. The 455 specifications require a new pile cushion be used for each pile. A Note should be made in the Pile Driving Record when changing pile cushions as generally the blow count will increase as the new cushion compresses giving a false sense of increased bearing capacity. If the pile is getting close to taking up (achieving bearing) and the pile cushion has to be changed, the Engineer may want the have a certain number of hammer blows put on the new cushion prior to getting back on the pile and commencing driving Release 10 July

90 Check Pile Cushion October 2018 Pile Driving Inspector Course Release 10, Module 7-90 This picture illustrates a burned cushion. Release 10 July

91 Check Pile Cushion October 2018 Pile Driving Inspector Course Release 10, Module 7-91 The following video shows Contractor personnel changing a pile cushion. Note, that they are not far from running out of pile. Click brings in short video of pile cushion being changed. Release 10 July

92 Replace Charred or Burning Cushion October 2018 Pile Driving Inspector Course Release 10, Module 7-92 This picture shows a pile driving where the pile cushion is already burning. A pile cushion change should be made. Release 10 July

93 Replace Charred or Burning Cushion October 2018 Pile Driving Inspector Course Release 10, Module 7-93 The following video shows a pile driving where the pile cushion is burning. Click brings in video of burning cushion Release 10 July

94 Replace Charred or Burning Cushion October 2018 Pile Driving Inspector Course Release 10, Module 7-94 Here is another video of a pile cushion burning Click- brings in video of burning cushion- Release 10 July

95 Burning Cushion October 2018 Pile Driving Inspector Course Release 10, Module 7-95 This video shows a pile cushion burning in the trash. Be observant for where burning cushions are disposed of. Can be a fire hazard. To prevent fires, some contractors placed burning cushions on water before discarding them. Click brings in short video (15 sec.) showing discarded cushion burning in the trash. Release 10 July

96 Pile Damage During Driving October 2018 Pile Driving Inspector Course Release 10, Module 7-96 Steel piles are more susceptible to damage from compressive stresses than from tension. Here is a picture of a pipe pile that has suffered extensive damage due to compression stresses. The original length of this pipe pile was the same as the piles shown in the back. Notice also the point protector in the tip. Regardless the pile was damaged and compressed so much that the length was reduced dramatically. Remember refusal is 20 blows per inch, not 240 blows per foot. Release 10 July

97 Pile Damage During Driving October 2018 Pile Driving Inspector Course Release 10, Module 7-97 This picture shows H piles after being damage in compression during driving. Release 10 July

98 Typical causes of damage Transporting Steel Strength Lifting Driving (Compression) Welding Splices Steel Piles Possible indicators during driving Pile moving out of position during driving Abrupt blow count change Types of damage Bending Buckling Accordion Splitting October 2018 Pile Driving Inspector Course Release 10, Module 7-98 Listed on this table are the causes of damage on steel piles and possible indicators during driving. When piles move out of position during driving it may indicate excessive bending and buckling. Abrupt blow count change may be caused by splitting, buckling or accordion damages. Release 10 July

99 Pile Damage During Driving October 2018 Pile Driving Inspector Course Release 10, Module 7-99 Use to discuss damage to concrete piles during driving. Contractor kept saying piles were good and getting penetration. PDA said otherwise. Pile pulled and the PDA was right. Release 10 July

100 Concrete Piles October 2018 Pile Driving Inspector Course Release 10, Module Here are the typical damages and common causes for concrete piles. Spalling and slabing may be caused by excessive compression stresses, which could happened when the cushions are getting used up or burning. Low concrete strength may play a part on this type of damage too. Tip damage and longitudinal cracks may be created near the tip at high eccentric compression stresses. Longitudinal cracks at the top may be created by excessive compression stresses in voided piles at the top. Excessive driving, particularly going beyond refusal may create tip damage. Transverse cracks may occur due to poor handling and lifting of the piles which creates excessive bending stresses. Also transvers tension cracks may happen on easy driving. Unfortunately these cracks are usually located below ground. Puffs of concrete dust coming out of the side of the pile indicates the presence of transverse cracks. Pile walking out of position may indicate a pile already broken Abrupt blow change may indicate a pile damage. Release 10 July

101 Pile Heave Pile heave is the upward movement of a pile from its originally driven elevation. Drive the piles in an approved sequence to minimize the effects of heave and lateral displacement of the ground. Monitor piles previously driven in a pile group for possible heave during the driving of the remaining piles. When required by the Engineer, take elevation measurements to determine the magnitude of the movement of piles and the ground surface resulting from the driving process. Redrive all piles that have heaved 1/4 inches or more unless the Engineer determines that the heave is not detrimental to pile capacity. The Department will pay for all work in conjunction with redriving piles due to pile heave under the pile redrive item. October 2018 Pile Driving Inspector Course Release 10, Module Release 10 July

102 Learning Outcome Unless otherwise approved by the Engineer, used pile cushions may be utilized to drive up to how many additional piles? A. None B. 1 C. 2 D. No limit Pile Heave refers to. A. The unloading of piles from the transport vehicle. B. The downward movement of a previously driven pile. C. The upward movement of a previously driven pile. D. The act of loading the pile into fixed leads. October 2018 Pile Driving Inspector Course Release 10, Module Please try to answer to the following questions: Unless otherwise approved by the Engineer, used pile cushions may be utilized to drive up to how many additional piles? Pile Heave refers to Release 10 October

103 Learning Outcomes Monitor and verify proper marking of the piles per contract documents and standards Verify & document contractor compliance with applicable tolerances Monitor, verify and document pile driving operations Identify applicable 455 Specifications October 2018 Pile Driving Inspector Course Release 10, Module Release 10 July

104 ANY QUESTIONS? October 2018 Pile Driving Inspector Course Release 10, Module Release 10 July