614Piling Walls

Division 700 — :

MATERIAL SUBSECTION Fine Aggregate 702.1 Fly Ash 707.4 Portland Cement 701.1 Reinforcing Steel 709.1 Steel Piles and Splices 709.12 Wales 709.12 614.3-DRILLING: A drilled hole is required for the buried length of the pile. A minimum of ten (10) feet of the pile, is to be placed in bedrock/shale. Deviation from this requirement will be controlled by a Plan note. The total estimated pile lengths and the depths to the estimated bedrock/shale line are shown in the plans. Should the elevation of t he actual bedrock/shale vary from the estimated elevation by more than 2.5 feet, the Engineer must approve the hole prior to placement of the pile. The material from the drilled hole shall be removed and disposed of by the Contractor. Particular care mu st be taken in the drilling operation to avoid deflecting the bit along a sloping bedrock/shale line. To verify proper alignment, the Contractor shall measure and record the vertical alignment of the hole using a plumb bob or other acceptable method. Pil e alignment shall allow direct welding of wale to piles. Preferably, the diameter of the drilled hole shall be a size that will allow the pile, while being slowly lowered into the hole, to reach the bottom of the hole under the impetus of the pile weight. The minimum hole diameter shall be two (2) inches larger than the diagonal distance across the pile cross section. Temporary casing of holes may be needed to maintain an open clean hole through the soil overburden. There will be no additional compensat ion for temporary casing. The cost of any casing used shall be included in the unit price bid for piling. 614.4-INSTALLATION OF PILES: Piles shall be located as shown on the Plans or as directed by the En gineer. Piles shall be installed with the pile center within one (1) inch of the Plan location. The piles must be prevented from rotating, so that the pile axis is within five (5) degrees of the position shown on the Plans. Boreholes that have collapsed shall be re -drilled or cleaned to the satisfaction of the Engineer. Obstacles that impede the placement of the piles shall be removed. Tapping on the pile(s) to reach its intended tip elevation(s) is prohibited. Driving piles with a hammer is prohibited unless required in the Plans. It is desirable that piles be installed without splicing; however, at the direction of the Engineer splices may be made. Splice lengths at the top of the piles may be butt welded provided the splice lengths are less than the required splice plates. No pa yment will be made for cut -offs. Welding shall be in accordance with subsection 615.5.7. The drilled hole shall be pumped free of water and shall be reasonably free of fall -in soil or other debris prior to the placement of the concrete or grout. When unable to remove the water, the concrete or grout shall be pumped or tremied through a pipe beginning at the bottom of the drilled hole. The pipe shall be slowly raised ensuring the pipe end remains at least two (2) feet below the surface of the concrete or grout. A means of positively measuring the elevation of the concrete or grout as it is placed shall be provided by the Contractor. After placing the concrete or grout below water table, the Contractor has the option of either pumping or pouring directly into the hole the remainder of the concrete or grout provided the hole can be pumped to remove remaining water. Placing the concrete or grout from the bottom of the hole to the bottom of the lagging shall be accomplished in one continuous operation. Accurate records shall be maintained by the Contractor showing the depth to which each pile was placed, the plumbness, the amount of material used, depth of bedrock/shale, and any unusual conditions encountered during the pile installation. These records shal l be given to the Engineer at the competition of the project. 614.5-CONCRETE OR GROUT: Piles will be protected from corrosion and sealed by the placement of concrete or grout, from the bottom of the hole to the bottom of the lagging or as directed by the Engineer. Vibration of the concrete or grout is not required. The Contractor shall complete all concrete or grout operations within 24 hours of drilling each hole. The Contractor will inform the Engineer, at the preconstruction conference, as to whether grout or concrete will be used. Intermixing of concrete and grout will not be allowed, unless approved by the Engineer. Concrete shall be in accordance with Section 601, Class B. The job site and A-bar testing are waived. Grout shall be furnished, tested and placed in accordance with the requirements specified herein. Quality Control of the grout is the responsibility of the Contractor as designated in Materials Procedure MP 601.03.50. The Contractor shall maintain equipment and qualified personnel, who shall direct all field inspection, sampling, and testing necessary to determine the magnitude of the various properties of the grout governed by the Specifications and shall maintain these properties wi thin the limits of this Specification. The Quality Control Plan designated in MP 601.03.50 shall be submitted to the Engineer at the pre -construction conference. Work shall not begin until the Plan is reviewed for conformance with the contract documents. The required 7 -day compressive strength of the grout shall be a minimum of 1,600 psi. Piling which has been installed with grout which does not attain the 1,600 psi strength in 7 days shall be paid for at a reduced unit price equal to 80% of the unit bid price for steel pile. The penalty would include the entire length of each pile which has been installed with failing grout. Grout with compressive strength of less than 1,000 psi shall be evaluated by the Engineer as to the adequacy for the use intended. All grout evaluated as unsatisfactory for the use intended shall be removed and replaced or otherwise corrected by, and at the expense of, the Contractor as required in 105.3. A grout strength test shall consist of testing three six (6) inch x twelve (12) inch cylindrical specimens. The test results shall be the average of the three specimens. A minimum of one set of three specimens shall be made for each day’s operations. 614.6-PAINTING: All surfaces from the top of the steel pile, down to and including two (2.0) feet below the top of the anticipated concrete or grout line shall be cleaned and painted prior to installation. The method of surface preparation shall be hand tool cleaning to SSPC-SP-2. The paint system shall consist of one-coat of epoxy mastic meeting the requirements of 711.12 applied at a minimum dry film thickness of 5 mils (125 μm). If no concrete or grout is required in the Plans, the entire pile shall be painted. 614.7-LAGGING AND BACKFILLING: Lagging of the type and size as specified on the Plans shall be installed between the piles. Timber or steel lagging shall not be use unless otherwise shown in the plans. Back filling and restoration of the roadway template shall be as shown on the Plans. Precast concrete lagging shall be fabricated in accordance with the requirements of MP 604.02.40 and shall have a minimum 28- day concrete compressive strength of 3,000 psi and an entrained air content of 7% ± 2.5%. Precast concrete lagging shall be used to the maximum exposed height as follows: For exposed heights of up to eight (8) feet, six (6) inch (minimum) lagging thickness shall be used. For exposed heights greater tha n eight ( 8) feet and less than sixteen ( 16) feet, eight ( 8) inch (minimum) lagging thickness shall be used. These minimum thicknesses are applicable up to a maximum center to center piles spacing of six (6) feet. Other spacings, exposed heights, and minimum thicknesses shall be allowed as shown on the plans. 614.8-METHOD OF MEASUREMENT: The quantity of piles will be measured in linear feet of piles installed and accepted for the wall. The quantity of lagging will be measured in square feet installed and accepted as measured by the total area of lagging as measured through all wall elements, without deductions for gaps between lagging, piles, etc. 614.9-BASIS OF PAYMENT: The quantities will be paid for at the contract unit prices bid for the items listed below, which prices and payments shall be full compensation for furnishing all materials and doing all the work herein prescribed in a workmanlik e and acceptable manner, including all labor, tools, equipment, supplies, and incidentals necessary to complete the work. The cost of drilling, concrete, grout, wales, and painting shall be included in the price bid for the piles. Payment will be made af ter receiving and accepting the record of piling installation as described in Section 614.4.