CONTRACTOR AND EQUIPMENT ARRIVE ON-SITE

Transcription

1 Lesson 5 Inspector CONTRACTOR AND EQUIPMENT ARRIVE ON-SITE Drilled Shaft Installation Plan 5-1 Version 1-1/15 5-1

2 Learning Outcomes Identify and understand the Role and Duties of the Inspector Verify and Inspect On-site Equipment Verify Protection of Existing Structures is implemented Identify the applicable 455 Specifications 5-2 Version 1-1/15 5-2

3 Inspector s Role What is the Inspector s Role? To serve as a representative of the State and ensure the work is performed in accordance with the approved plans and specifications. 5-3 Version 1-1/15 5-3

4 Inspector s Role To know the specifications, both the State Standard Specifications and the job Plans and Specifications. To record and document activity relative to the Plans and Specifications. Raise a red flag soon enough to make a difference if work is performed outside of those specifications. Keep the Project Administrator Informed. Call the Project Administrator if judgment is needed to interpret a Specification. 5-4 Version 1-1/15 5-4

5 Inspector s Role Remember that you are the Department s Representative Do not delay or interfere with the Contractor unnecessarily Remember the Goal- Constructing a project in accordance with the approved documents 5-5 Version 1-1/15 5-5

6 Inspector s Role Keep the Project Administrator Informed Notify the Project Administrator soon enough that appropriate decisions or Corrective Actions can be made or implemented in a timely fashion to reduce the impact to the project schedule, cost or quality. 5-6 Version 1-1/15 5-6

7 Inspector s Role KNOW THE PLANS KNOW THE SPECIFICATIONS 5-7 Version 1-1/15 5-7

8 Inspector s Responsibilities Be a Recorder Make accurate and unbiased observations Document events: complete & consistent Perform your duties promptly Be a Reporter Complete reports & forms accurately Keep forms and diary up-to-date Keep Project Administrator informed 5-8 Version 1-1/15 5-8

9 Communication & Coordination With Project Administrator If interpretation of specifications is required, contact the Project Administrator If work is performed outside of the plans or specifications, contact the Project Administrator For work or items requiring Approval, contact the Project Administrator Talk to Project Administrator daily Contact PA soon enough to make a difference and to minimize impacts to cost or schedule 5-9 Version 1-1/15 5-9

10 CPAM Miscellaneous Shafts Miscellaneous Drilled Shafts To improve the quality of miscellaneous drilled shafts installation, DCEs shall obtain technical support from the District Geotechnical Office on drilled shaft projects involving mast arms, cantilever signs, overhead truss signs, high mast light poles or other miscellaneous structures shown in the Contract Documents. This process includes review of Drilled Shaft Installation Plans, conduct at the earliest predrill/pre-concrete pour meetings, as required for quality assurance checks and inspector assistance etc. Project Administrators shall notify the District Geotechnical Offices of the construction schedules of the miscellaneous drilled shafts for the projects so they can schedule time to assist Version 1-1/

11 Communication & Coordination Pre-Drilling Meeting Review the approved Drilled Shaft Installation Plan, and have any questions answered Discuss applicable Special Provisions Discuss administrative issues Discuss and resolve any conflicts. Discuss any special site considerations 5-11 Version 1-1/

12 Communication & Coordination With Contractor Remember, you are a team Do Not direct the Contractor in their work If you observe potential non-conformance, notify the Contractor, in advance, to avoid the situation occurring Avoid delaying Contractor 5-12 Version 1-1/

13 Inspector s Role on Drilled Shafts Check Drilled Shaft Installation Plan Verify Contractor Equip. Verify hole location Verify template Verify setup for plumbness, etc. Record Pilot Holes Verify proper steel size, length, etc. Verify proper ties Verify proper spacers and intervals Verify CSL Tubes Verify anchors placement plate alignment Monitor concrete volumes Prepare Concrete Placement Log CONTRACTOR SET UP SHAFT EXCAVATION AND CLEANING PLACING STEEL CONCRETING OPERATION POST INSTALLATION Verify testing of Slurry Identify Soils & Rock Prepare Excavation Logs Verify Shaft Depth Perform Shaft Inspection Prepare Shaft Inspection Log Verify hole cleanliness Document casing use, type, length Verify Const. Tolerance compliance Verify pay quantities Verify integrity testing Complete required forms Check CSL tubes 5-13 Version 1-1/

14 Assemble Your Toolbox Casey 5-14 Version 1-1/

15 Tools Checklist Checklists Prevent Forgetting 5-15 Version 1-1/

16 Checklist The Drilled Shaft Inspector s Checklist can assist you in performing you duties Version 1-1/

17 Project Document Check COMPONENT Plan Revisions CHECK Always check for revised sheets to see if there are any changes that affect the shaft construction. Key Sheet Does Project ID No., location, etc. agree with the information you were provided? Summary of Pay Items Do the pay quantities and items agree? 5-17 Version 1-1/

18 Project Document Check COMPONENT Utilities CHECK Does there appear to be any conflicts with production or test shafts? If so, are there provisions for addressing these conflicts? Traffic Control Does there appear to be any conflicts with production or test shafts? Does the sequence of shaft installation conflict? If so, are there provisions for addressing these conflicts? 5-18 Version 1-1/

19 Structural Plan Sheet Check STRUCTURAL PLANS General Notes CHECK Compare with the Drilled Shaft Data Table. Do any Notes contain changes to the specifications or specification applications? General Plan & Elevation Does the number of bent/piers or shaft locations match the Drilled Shaft Data Table? Do the elevations shown compare favorably with the Drilled Shaft Data Table? 5-19 Version 1-1/

20 Structural Plan Sheet Check STRUCTURAL PLANS Rpt. of Borings Foundation Layout CHECK Are water tables/piezometric levels shown? Do the boring(s) extend beyond the proposed bottom of shaft elevations? Does the foundation layout match the Drilled Shaft Installation Plan relating to number, sequencing, elevations, etc.? 5-20 Version 1-1/

21 Learning Outcome What is the Inspector s Role? As a Recorder and Reporter, the Inspector s duties include what? 5-21 Version 1-1/

22 Learning Outcome When should the Inspector contact the Project Administrator? It is enough for the inspector to know the Standard Specifications. True or False? 5-22 Version 1-1/

23 Contractor & Equipment Arrive 5-23 Version 1-1/

24 Inspector s Checklist 5-24 When the Contractor and their equipment arrive on-site, there are a variety of items that you, the I nspector, are responsible for c hecking and verifying. From ver ifying the equipment on-site matches that in the a pproved Drilled Shaft Installation Plan t o assessing Contractor compliance with any required Protection of Existing Structures, the Inspector is quite busy. Version 1-1/

25 Verify Equipment Can use Drilled Shaft Installation Plan submittal to verify equipment Need to check & document augers, bits, buckets, etc. -Type -Size - Condition 5-25 The Contractor has to provide det ailed information on their equipment in the Drilled Shaf t installation Plan. Version 1-1/

26 Verify Equipment Check diameter of bits Check condition of auger and teeth Length Diameter Determine length of tool Cutting teeth 5-26 Though we cannot and do not want to tell the Contractor what type of bit to use, they have provided the information on their equipment in t he Drilled Shaft Installation Plan. The Inspector should verify that the augers and bits are as detailed in the plan, especially paying attention to the diameters, condition and length of the tools. Bits should be checked for missing or broken teeth, and types on site. Augers checked for broken or missing cutting blades, damaged flights, etc. It is important to measure the height of these tools as you will need this information when determining depths. Version 1-1/

27 Verify Equipment Is the equipment in good shape? Bent kelly 5-27 The Inspector typically does not have the authority to reject the Contractor s tools, however, it is the Inspector s responsibility to document the condition of the equipment and tools. The Inspector must document all of the tools, as q uestions may arise at a later time concerning drilling difficulties, etc. Document any changing of or repairing of tools, such as changing teeth on a bit, etc. Version 1-1/

28 Verify Equipment Bucket Template Auger Bit 5-28 Version 1-1/

29 Verify Equipment 5-29 Section 400 of the Standard Specifications states that tremies are to be a minimum of 10 inches in diameter. Version 1-1/

30 Verify Equipment 5-30 Version 1-1/

31 Verify Equipment 5-31 Version 1-1/

32 Verify Equipment Contractor was trying to use this bent casing. Cutting off bent part so they could use Casings can be bent or deformed at the tip during installation into hard strata. Contractor then has difficulty removing the drilling tool from the hole making it difficult to remove the cuttings. The auger will catch on the bent portion of the casing. Version 1-1/

33 Casing Casings: Ensure that casings are metal, of ample strength to withstand handling and driving stresses and the pressure of concrete and of the surrounding earth materials, and that they are smooth and water tight. Ensure that the inside diameter of casing is not less than the specified size of shaft except as provided below. The Department will not allow extra compensation for concrete required to fill an oversize casing or oversize excavation Version 1-1/

34 Protection of Existing Struct Protection of Existing Structures: When the Plans require excavation or foundation construction operations in close proximity to existing structures, take all reasonable precautions to prevent damage to such structures. The requirements described herein apply to all types of structures (on or off the right-of-way) that may be adversely affected by foundation construction operations (including phase construction) due to vibrations, ground loss, ground heave, or dewatering. Protect utilities as described inthe applicable provisions of Section Version 1-1/

35 Protection of Existing Struct Protection of Existing Structures: Continued Survey and monitor structures for settlement in a manner approved by the Engineer, recording elevations to foot. Employ a qualified Specialty Engineer to inspect and document the condition of structures prior to and after construction of excavations and foundation construction. Inspect and monitor the following structures: (1) shown in the plans. (2) within a distance of ten shaft diameters or the estimated depth of excavation, whichever is greater. (3) within a distance of three times the depth of excavation for the footing Version 1-1/

36 Protection of Existing Struct Protection of Existing Structures: (Continued) Take elevation; (1) before beginning construction, (2) daily during the driving of any casings, piling, or sheeting, (3) weekly for two weeks after stopping driving, (4) during excavation, (5) during blasting, (6) or as directed by the Engineer. Notify the Engineer of any movements detected and immediately take any remedial measures required to prevent damage to the existing structures Version 1-1/

37 Protection of Existing Struct. Distance from Shaft to be monitored and Surveyed (pre and post-construction) D D = 10 Shaft diameters OR Depth of Excavation 5-37 Version 1-1/

38 Protection of Existing Struct Protection of Existing Structures: (Continued) The Department will make the necessary arrangements to provide right-of-way entry to the existing structures. Adequately document the condition of the structures and all existing cracks with descriptions and pictures. Prepare two reports documenting the condition of the structures: one report before beginning foundation construction operations and a second report after completing foundation construction operations. The Department will take ownership of both reports. Do not perform pre-driving and post-driving surveys of the condition of bridges owned by the Department except when shown in the Contract Documents Version 1-1/

39 Protection of Existing Struct. When shown in the Contract Documents, employ a qualified Specialty Engineer to monitor and record vibration levels during the driving of casings, piling, sheeting, or blasting operations. Provide vibration monitoring equipment capable of detecting velocities of 0.1 in/s or less. Upon detecting settlement or heave of foot, vibration levels reaching 0.5 in/s, levels otherwise shown in the Contract Documents, or damage to the structure, immediately stop the source of vibrations, backfill any open drilled shaft excavations, and contact the Engineer for instructions Version 1-1/

40 Learning Outcome The Contractor is preparing to install a 48 in. drilled shaft to a depth of 90 ft. Answer the following. 1. Structures within what distance must be monitored by the Contractor? Within a distance of ten shaft diameters....or the estimated depth of excavation, 5-40 Version 1-1/

41 Excavation Excavation: Complete all excavation of the foundations prior to installing piles or shafts unless otherwise authorized by the Engineer Version 1-1/

42 Abutment (End Bent) Fill Abutment (End Bent) Fill: Place and compact the fill before installing end-bent piling/shafts, except when: (1) driving specified test piling in end bents or, (2) the plans show uncased piles through proprietary retaining wall fills. When installing piles/shafts or casing prior to placing fill, take necessary precautions to prevent displacement of piles/shafts during placing and compacting fill materials within 15 feet of the piles/shafts or casing. Reference and check the position of the piles/shafts or casing at three approximately equal intervals during construction of the embankment Version 1-1/

43 Abutment (End Bent) Fill Abutment (End Bent) Fill: (Continued) Provide permanent casings installed prior to placement of the fill, for all drilled shafts through mechanically stabilized fills (for example, behind proprietary retaining walls) for shafts installed after fill placement. Install temporary casings through the completed conventional fill when permanent casings are not required. Provide permanent casings, if required, before the fill is placed extending a sufficient distance into the existing ground to provide stability to the casings during construction of the abutment fill Version 1-1/

44 Cofferdams 5-44 A Cofferdam is a closed t emporary wall, typically built with steel sheet piles and wh ich allows the protected area to be dewatered and be constructed in the dry. In FDOT projects cofferdams are used to construct pier fo undations for bridges and in spec ial drainage structure construction. The foll owing slides illustrate a cof ferdam installed for the construction of a bridge p ier. Even t hough is mostly temporary, in some cases the cofferdam is left in place as it is not practical or cannot be removed. Version 1-1/

45 Cofferdams 5-45 Version 1-1/

46 Cofferdams 5-46 Version 1-1/

47 Cofferdams Cofferdams: Construct cofferdams as detailed in the plans. When cofferdams are not detailed in the plans, employ a Specialty Engineer to design cofferdams, and to sign and seal the plans and specification requirements. Send the designs to the Engineer for his records before beginning construction. Provide a qualified diver and a safety diver to inspect the conditions of the foundation enclosure or cofferdam when the Contract Documents require a seal for construction Version 1-1/

48 Cofferdams Cofferdams:Continued. Equip these divers with suitable voice communications, and have them inspect the foundation enclosure and cofferdam periphery including each sheeting indentation and around each piling or drilled shaft to ensure that no layers of mud or other undesirable materials were left above the bottom of seal elevation during the excavation process. Also have the divers check to make sure the surfaces of the piles or drilled shafts are sufficiently clean to allow bond of the concrete down to the minimum bottom of seal elevation Version 1-1/

49 Learning Outcomes Identify and understand the Role and Duties of the Inspector Verify and Inspect On-site Equipment Verify Protection of Existing Structures is implemented Identify the applicable 455 Specifications 5-49 Version 1-1/

50 Questions? ANY QUESTIONS? 5-50 Version 1-1/

51

52 Drilled Shaft Reinforcement/Spacers Log Drilled Shaft fluid/slurry testing log

53 Lesson 5-Contractor & Equipment Arrive On-Site DRILLED SHAFT INSPECTOR S CHECKLIST The following is a general checklist to follow when consulting a Drilled Shaft. The answer to each of these should be yes unless plans, specification or specific approval has been given otherwise. CONSULT WITH RESPONSIBLE ENGINEER FOR YOUR SPECIFIC PROJECT RESPONSIBILITIES. EARLY REQUIREMENTS YES NO NA 1. Do you have a copy of the Plans including latest revisions & located relevant items (ex. Drilled Shaft Data Table)? 2. Do you have and have you reviewed the accepted Drilled Shaft Installation Plan submitted by Contractor ( ? 3. Is a Shaft Inspection device (SID) to be used? 4. Do you have the supplemental specifications for this project? 5. Does the contractor have an approved Concrete Mix Design and do you have a copy ( )? 6. Has the contractor provided the required Slump Loss Test for their mix design ( )? 7. Are Pilot Holes required ( )? a. If Yes, how many, what depths. And where? b. What type of sampling (Cores versus SPT)? c. Do you have samples? Does the Engineer have results? d. Do you have revised/confirmed tip elevations based on Pilot Holes? 8. If cores are required at the bottom of the shaft, does the Contract have the correct coring equipment ( )? 9. Are Load tests required (455-2)? 10. Have you scheduled or attended a Pre-Installation meeting with the PA/Geotechnical Engineer? PRE-INSTALLATION REQUIREMENTS 11. Has the Contract met the requirements of , Protection of Existing Structures? 12. Has the site preparation been completed for footings/excavations/abutments in accordance with & ? 13. Have the requirements of vibrations of Freshly Placed Concrete been met? 14. If a Cofferdam is required, does the Contractor have a qualified diver and safety diver for inspections in accordance with , cofferdams? 15. If underwater diving is required, are the divers equipped with voice communications, per , Cofferdams? 16. Does the contractor have the equipment indicated in the Drilled Shaft Installation Plan on-site ? 17. If casing is to be used, does it meet the requirements of , Casing? 18. If the Contractor plans on using a pre-mix slurry, do they have the equipment to mix it? 19. Does the contractor have the equipment indicated in the Drilled Shaft Installation Plan on-site ? 20. If casing is to be used, does it meet the requirements of , Casing? 21. If using polymer, has the Contractor provided the required data ( )? TEST HOLE/TEST SHAFTS 22. Is this a Miscellaneous Shaft? If so, no separate Test Hole required (455-18, Test Holes)? 23. Has the Contractor located the Test Hole away from the production shafts ore as indicated in the Plans (455-18, Test Holes) or is it at permanent locations? 24. If OD casing used, what is the additional depth required ( , Casing)? 25. Has the Contractor performed a successful Test Hole, per Plan requirements and , Test Holes? 26. If not, has the Contractor revised their technique and/or equipment (and the revision approved) to successfully construct the Test Holes? 27. Was the Test Hole cutoff a minimum of 2 ft. below the groundline, per , Test Holes? SHAFT CONSTRUCTION - EXCAVATION 28. Is the shaft being constructed in the correct plan location and within tolerance (455-20, Construction Tolerances)? 29. Does the Contractor have a bench mark so the shaft can be construction and inspected in the proper elevations? 30. Is the template required ( , Templates) and has the Contractor met the requirements? 31. Is the Contractor using a surface casing as a minimum to meet Section , General Methods and Equipment? 32. If mineral slurry is being used, does the Contractor have a CTQP qualified technician to test the slurry and report the results in accordance with , Slurry? 33. Are the proper type and number of tests being performed per , or ? 34. If being used, is the slurry level being properly maintained (a minimum of 4ft above the highest piezometric head) in accordance with , Slurry? Version 1.0-1/

54 Lesson 5-Contractor & Equipment Arrive On-Site DRILLED SHAFT INSPECTOR S CHECKLIST Page 2 SHAFT CONSTRUCTION EXAVATION (Continued) YES NO NA 35. Do you have the required drilled Shaft Forms? 36. Are you filling out the Shaft Excavation Form, as the excavation proceeds? 37. Is the shaft to the proper depth ( , Depth)? 38. Was the shaft over drilled & extra reinforcement placed ( )? Was this authorized? 39. Is the shaft being excavated within the allowable axial tolerances ( ), Dimensions and Alignment)? 40. If slurry is being used, is the Contractor taking the required slurry tests in accordance with Fluid in the Excavation at the Time of Concrete Placement? (Applies to ALL shafts) 41. If so, are the test results within the allowable limits per or ? 42. Does the shaft excavation meet the 36 hour time limit per ? 43. If the shaft was not excavated within the applicable time limit, has the shaft been overreamed in accordance with ? 44. If using mineral slurry, has it been in contact with the bottom 5 ft. of the shaft for over 12 hours ( )? 45. If yes, has the bottom 5 ft of the shaft been overreamed per ? 46. Does the shaft bottom meet the requirements of or ? 47. Have you completed the proper Shaft Inspection Forms? REINFORCING CAGE 48. Are the correct number and size of bars being used per the Plans? 49. Is the cage properly tied in accordance with , Cage Construction and Placement? 50. If the cage was spliced, was it performed in accordance with , Splicing Cage? 51. Are the proper number of bottom spacers and side spacers being used ( , Support, Alignment and Tolerance)? 52. Are the CSL tubes, the correct diameter, steel, spaced, aligned and secured inside the cage per , Cross-Hole Sonic Logging Tubes? 53. Do the CSL tubes extend from the bottom of the shaft to the minimum of 30 inches above the top of the shaft, ground or water surface, whichever is higher ( , Cross-Hole Sonic Logging Tubes)? 54. Was a simulated or mock CSL probe inserted and run down each CSL to check for serviceability ( , Cross- Hole Sonic Logging Tubes)? 55. Are the CSL tubes sealed, watertight, and filled with clean potable water prior to concreting ( , Cross-Hole Sonic Logging Tubes)? 56. Is the cage secured from settling and/or rising (during concrete placement)? (Elevation check) CONCRETE PLACEMENT 57. Does the tremie or pump meet the requirements of , & Tremies and Pumps? 58. Is the tremie or pump line sealed and watertight? 59. Immediately prior to concrete placement, was the slurry tested per , Fluid in the Hole at time of Concrete Placement? 60. Is the tremie/pump line maintained in the concrete with a head above it? 61. Did you complete the concrete placement forms and the concrete curves? Does the placement curve appear OK? 62. Project Administrator notified of concrete curves with irregularities? 63. Did the Contractor overflow the shaft until good concrete flowed? 64. Was the concrete placed within the time allowed by the Slump Loss Test ( )? POST INSTALLATION 65. Did you check the CSL tubes following concrete placement to ensure they are still full of water ( , Cross-Hole Sonic Logging Tubes)? 66. If in open water, is the shaft protected for 7 days or until strength of 2,500 psi has been achieved ( , Curing)? 67. Is all casing removed to the proper elevation per Forms? 68. Does the drilled shaft meet the construction tolerances (455-20, Construction Tolerances)? 69. Have you filled out the Drilled Shaft Construction and Pay Summary form? Version 1.0-1/15

55

56

57

58

59

60

61

62

63

64

65

66