496 preinstallation test boring location, which at a minimum shall include constructing drill pads and access roads. Unless otherwise directed, the preinstallation test borings are to be extended a minimum depth of two ( 2) upper drilled shaft diameters but not less than ten (10) feet below the planned tip elevation of the rock socketed drilled shaft shown on the plans. Standard Penetration Testing (SPT) and sampling shall be performed at five ( 5) foot intervals in the preinstallation borings in accordance with AASHTO T 206. Roc k coring will be performed in accordance with ASTM D2113 using a wireline core barrel system and will commence immediately upon obtaining an SPT value of 50 blows per six (6) inches or less on bedrock. The recovered core sample size will be approximately two ( 2) inch diameter (NX or NQ size). Additional preinstallation test borings in other locations may be required where directed by the Engineer. Test boring logs of each preinstallation boring will be prepared by the Division and will be provided to the Contractor within three ( 3) working days of completion of the test boring. The preinstallation test borings logs will describe the type and thickn ess of all soil and rock layers, and locate the presence of groundwater, open joints, voids, soft rock, or other deleterious material. All recovered soil and rock samples shall be maintained by the Division and stored on site at suitable location, provide d by the Contractor, until completion of the project. Within 10 working days after completion of preinstallation core hole, the Engineer will notify the Cont ractor of the final tip elevations for each drilled shaft location. 625.7.2.2 -Wet or Dry Hole De termination: The Division will check the depth of water at the bottom of the drilled shaft. If the depth does not increase by more than twelve (12) inches over a 1 -hour period, the hole will be considered dry. Otherwise, the hole will be considered wet. 625.7.2.3 -Plumbness: Contractor shall provide notice to the Technical Support
Division vi — a e -mail ( DOHDrilledShafts@wv.gov ) five ( 5) working days prior to the date
each drilled shaft will be ready for inspection. Plumbness of the rock socketed drilled shaft/rock socket shall be measured by the Division by measuring the geometry of the drilled shaft excavation using SHAPE, Sonicaliper, or other suitable means. For any rock socketed drilled shaft, the maximum permissible deviation from plumb shall be 1.5% measured with respect to the vertical axis at the center of the drilled shaft excavation. The Contractor shall provide suitable access and means for lowering inspection equipment into the drilled shaft excavation. For any rock socketed drilled shaft at its top, the maximum deviation of the center shall be three ( 3) inches from its project plan location. The maximum deviation of the f inished top of shaft from the plan elevation shall be minus one (1) inch or plus three ( 3) inches. An absolute minimum cover of three ( 3) inches to the reinforcing steel is strictly required. In the event of any deviations in the dimensional requirements , the contractor shall not proceed with construction of pier columns or cap until submission and approval of a corrective plan has been granted. 625.7.2.4 -Rock Sock Sidewall Inspection: Contractor shall provide notice to the Technical Support Division v ia e-mail ( DOHDrilledShafts@wv.gov ) five ( 5) working days 497 prior to the date each drilled shaft will be ready for inspection. The Division will inspect the rock socket side walls with a downhole camera or other suitable device. The Engineer shall evaluate the rock quality and construction, as outlined in 625.6.1.3. 625.7.2.5 -Shaft Bottom Cleanliness: Contractor shall provide notice to the Technical Support Division v ia e-mail (DOHDrilledShafts@wv.gov ) five ( 5) working days prior to the date each drilled shaft will be ready for inspection. The contractor shall clean the rock socket so tha t a minimum of 75% of the base will have less than ½ inches of sediment at the time of placement of the concrete. Sediment depth at any location shall not exceed 1 ½ inches. The Division shall determine shaft cleanliness by using a mini -SID, SQUID, or ot her suitable device. The contractor shall use an air -lift to achieve the required bottom cleanliness. The contractor shall begin concrete placement in the shaft within 3 hours after the shaft bottom cleanliness is approved. If concrete placement in the drilled is not started within 3 hours, the rebar cage shall be removed, and hole shall be re -inspected at no additional time to the Contractor or cost to the Division. 625.7.2.6 -In-place Concrete Quality Testing: The Contractor shall furnish and place the Crosshole Sonic Logging ( CSL) tubes and thermal integrity profiler (TIP) wires in all drilled shafts. The number of tubes and tip wires to be used shall be as specified in subsection 625.6.2.1 . The Division will perform the testing and provide a repor t of the drilled shaft integrity testing to the Contractor. The CSL tubes shall remain open in the shaft and be grouted by the Contractor after acceptance of that shaft. 625.7.2.6.1 -Crosshole Sonic Logging (CSL) : The nondestructive testing method known as CSL shall be used on any rock socketed drilled shaft which is constructed with the placement of concrete under wet conditions or as required in the plans . The testing shall not be conducted until at least three (3) calendar days after placement o f concrete is concluded in the drilled shaft and will be completed within fourteen (14) calendar days after such placement. The CSL tests shall be conducted in conformance with ASTM D6760 and by a testing company approved by Technical Support Division. The Contractor shall comply with the scheduling and notification requirements for drilled shaft construction outlined in Section 625.2.3 by contacting the following Technical Support Division e -mail address: ( DOH DrilledShafts@wv.gov ). This will allow Technical Support Division to provide a qualified company to perform testing within the time frames allotted for in this subsection. 625.7.2.6.1.1 -CSL Testing Results: The CSL test results will be compiled into a drilled shaft integrity testing report for each drilled shaft. The report will summarize and analyze any defect zones indicated on the logs. A copy of each report will be provided to the Contractor. 625.7.2.6.1.2 -Evaluation of CSL Test Results: The Engineer will review the report and, if the report determines that the drilled shaft is acceptable, will submit to the Contractor in writing within seven (7) calendar days approval to procee d with the work. The rating of the rock socketed drilled shaft integrity will consider the increases in first 498 arrival time (FAT) and the energy reduction relative to the FAT or energy in a nearby zone of good concrete. The criteria for rating the concret e from the CSL test will be: TABLE 625.7.2.6.1.2 Rating Criteria Good (G) FAT increases 0 -10% and energy reduction < 6 db Questionable (Q) FAT increases 11 -20% and energy reduction < 9 db Poor / Flaw (P/F) FAT increases 21 to 30% or energy reduction of 9 to 12 db Poor / Defect (P/D) FAT increases 31% or more or energy reduction >12 db Flaw or defect zones as indicated in Table 625.7.2.6.1.2 will be indicated on the logs and listed in a table within the r eport. The flaw or defect zones and their horizontal and vertical extent will be discussed in the report text. Flaws will be addressed by the Division if they affect more than 50% of the tested tube pairs at the same depth. Defects will be addressed by the Division if they affect two or more of the tested tube pairs at the same depth. At a minimum, addressing flaws and defects will include Crosshole Tomography (CT). If it is determined that the rating is less than Questionable, based on the results of the CSL and CT testing, the Division will require core drilling and sampling by the Contractor for further evaluation of the flaw or defect at no additional cost to the Division. The diameter, number, depth, and location of cores shall be as directed by t he Engineer. The acceptance of each drilled shaft shall be the decision of the Engineer, based on the results of the drilled shaft integrity testing report and other information on the drilled shaft placement. Rejection of a drilled shaft shall require c onclusive evidence that a defect exists in the drilled shaft, which will result in inadequate or unsafe performance under service loads. If the Non -Destructive Testing records are complex or inconclusive, the Engineer will require the Contractor to verify drilled shaft conditions by core drilling. If a flaw or defect is confirmed, the Contractor shall pay for all coring and grouting costs. If no flaw or defect is encountered, compensation for all coring and grouting will be in accordance with subsection 104.3 and 109.4. 625.7.2.6.1.3 -Remedial Action: In the case that any rock socketed drilled shaft is determined to be unacceptable, the Contractor shall submit a plan for remedial action to the Engineer for approval. The approval or rejection of the rem ediation plan may take up to fourteen (14) calendar days. If the remediation plan is rejected the Contractor shall revise the plan and submit it for approval and the approval time is restarted. Any modifications to the rock socketed drilled shaft and loa d transfer mechanisms caused by the remedial action will require calculations and working drawings stamped by a Professional Engineer licensed in the State of West Virginia for all foundation elements affected. All labor and materials required to perform remedial drilled shaft action shall be provided at no cost to the Division and with no extension of the contract time. 625.7.2.6.2 -Thermal Integrity Profiler (TIP): Perform TIP testing using the embedded thermal wire array, and in accordance with the ASTM D7949 (method b). Thermal integrity profiling is performed to evaluate shaft integrity and location of the reinforcing cage. The number of wires to be used shall be as specified in subsection 625.6.2.1 . Thermal wire cables shall b e connected to a thermal access port (TAP ) immediately following casting. 499 The Contractor shall provide cooperative assistance and labor as required to assist the
Division i — n inspecting the thermal wires prior to concreting the shaft. Prior to TIP testing ,
the contractor shall provide shaft installation details to the TIP consultant. Because the method relies on the heat of hydration, tip testing is generally performed between 8 and 48 hours of concrete placement (note the optimum TIP testing time is depe ndent on shaft size and concrete mix and could range from 4 to 72 hours ). 625.7.2.6.2.1 -Criteria to be used for acceptance or rejection of rock socketed drilled shaft using TIP testing: The rating of the shaft integrity using tip shall consider variatio ns in temperature as measured by the thermal wires. Potential local anomalies may be indicated by locally low temperatures relative to the average temperature at that depth, or average temperatures significantly lower than the average temperatures at othe r depths. The criteria for rating the concrete from the TIP test shall be: Satisfactory (s) = 0 to 6% effective radius reduction and cover criteria met Anomaly (a) = effective radius reduction > 6% or cover criteria not met When a tested shaft is categorized as anomaly (a), slices modeled at the area of question may be provided so that a structural evaluation of the shaft can be performed prior to implementing any corrective measures. Core drilling shall be performed to investigate problem areas f ound during TIP testing. 625.7.3 -Evaluation by Core Drilling: A rock socketed drilled shaft that is found to be unacceptable shall be core drilled by the Contractor in accordance with ASTM C42. Cores shall be four ( 4) inch nominal diameter. One or mo re core holes shall be drilled at the location(s) as determined by the Engineer. An accurate log of the core shall be kept, and the core shall be crated and properly marked showing the drilled shaft depth at each interval of core recovery. The core and o ne copy of the coring log shall be provided to the Engineer. The Engineer shall determine if the rock socketed drilled shaft is acceptable. The Engineer will submit to the Contractor in writing within seven (7) calendar days approval to proceed with the work. If the quality of the drilled shaft is determined to be unacceptable, then the Contractor shall proceed in accordance with subsection 625.7.2.6.1.3 . 625.8 -METHOD OF MEASUREMENT : Rock socketed drilled shafts and Rock Socket foundations will be measured by the linear foot. For payment purposes, the drilled shafts are the portion from the finished top of each rock socketed drilled shaft to the top of competent rock. Rock Socket is the portion from the top of competent rock to the bottom of the drilled shaft rock socket as shown in the plans or as directed by the Engineer. Each measured drilled shaft is to be complete in place, accepted, and ready to function. "Top of drilled shaft" is the top of concrete as shown in the plans. "Top of competent rock" is as tabulated in the drilled shaft schedules in the plans unless a difference of one (1) foot or more is found during drilling. 625.9 -BASIS OF PAYMENT : The accepted quantities of rock socketed drilled shaft foundations, measured as provided above, will be paid for at the contract unit price per linear foot; complete in place including excavation, slurry if required, tempora ry or permanent metal casing, steel reinforcing, concrete, curing, and any required forming and finishing. No additional payment will be made for temporary casing that remains in place and pressure grouting due to the Contractor ’s inability to stabilize a drilled excavation, for the need to place concrete by tremie or pumping, for the need to use slurry for drilling,