1015PROTECTIVE BARRIER

1006. 3(b) 1006. 3(e) is not allowed. Provide excavation and drilling equipment with a capacity to excavate to a depth of 120 % of the proposed drilled shaft length, but not less than 15 feet beyond the rock socket tip depths indicated . Submit the minimum output of the drill rig torque and crowd to the Representative. Do not excavate within three diameters of caissons with new concrete until 24 hours after concrete placement. If satisfactory foundation materials are encountered at other than the indicated elevations, adjust drilling depths as directed. Use permanent metal casing when indicated to prevent caving of the soil material, to exclude groundwater or surface water, and to form the non- drilled and drilled caisson, including the shaft section. Seal the casing a minimum of 2 feet into impervious materials and bedrock to create a tight seal. Use casing to control dimensions and alignment of excavations within tolerances and to execute other construction operations. If artesian water flow is encountered, extend the top of the casing to above the level required to achieve static water head conditions for proper placement of concrete. If a caving condition or excess groundwater is encountered, discontinue the drilling operation, and employ a construction method that prevents caving and groundwater infiltration, such as the installation of casings. Remove, as directed, caked material from the sidewalls and loose cuttings from the bottom of the excavation so that such material will not cause unanticipated settlement, reduce caisson capacity, or affect concrete strength. Do not expose the rock socket to water for more than 48 hours without approval. Ream rock socket exceeding 48 hours of water exposure, or that, as determined by the Representative, has deteriorated because of exposure to air or water, with an approved grooving tool to a depth of not less than 1/2 inch, or as directed. Reaming of the rock socket, if necessary, is incidental to drilling the rock socket. Unauthorized over -drilling, including the additional reinforcement and concrete resulting from over - drilling, will be at no additional cost to the Department. Promptly remove tools lost in the shaft during drilling and repair hole degradation caused by removal operations at no additional cost to the Department with no extension of contract time. Provide casing through soil and broken or unstable rock during hand cleaning and inspection of the excavation. If joining two or more sections of casing to obtain the required length, weld sections together as specified in Section 1105.03(m) to develop the full tensile strength of each section. Provide no interior splice plates. Maintain a log of excavation to complete the As -Built Record. (c)