Common use of Subsurface Exploration Clause in Contracts

Subsurface Exploration. In general, traffic control during our field investigation will be conducted along the proposed alignment using signs, cones, and an arrow board in accordance with the WATCH manual. Our surface investigation will include drilling exploratory borings. The purpose of the borings will be to: ▪ Obtain subsurface information along the pipe alignment. ▪ Collect undisturbed and bulk samples of the various soil types for laboratory testing. As indicated in the RFP, we plan to drill a total of 6 borings. Based on the existing profile, depth to pipe invert will range from 25.0 to35.0 feet below existing ground surface. We plan drill the borings between 25.0 and 50.0 feet below existing ground surface or to refusal, whichever is shallower. The borings will be drilled with a truck mounted rig (CME 75 or equivalent) equipped with 8-inch diameter hollow stem augers for soils sampling. Soils will be continuously logged and classified by the geologist/engineer in the field by visual examination in accordance with the Unified Soil Classification System. Undisturbed ring samples of the subsurface materials will be obtained at 5-foot intervals, at changes in soil profiles, or where unusual conditions are encountered. The relatively undisturbed ring samples will be obtained using a Modified California Sampler (2.4-inch inside diameter and 3.0-inch outside diameter) lined with thin-walled sample rings. The sampler will be driven into the bottom of the borehole with successive drops of a 140-pound hammer falling 30 inches. The number of successive drops of the driving weight (“blows”) required for each 6 inches of penetration will be shown on the boring log. The soil will be retained in brass rings (2.4 inches in diameter and 1.0 inch in height) and carefully sealed in waterproof plastic containers for shipment to the laboratory. Bulk samples of representative soil types will be collected in plastic bags from various depths and within a 5-foot zone of the pipe elevation. Groundwater levels, where encountered in the borings, will be recorded. The borings will be backfilled with soil/cement cuttings and compacted by pushing down with augers using the drill rig weight. The upper 1-foot will be filled with quick cement and the surface sprayed with black dye. If construction is delayed, the surface may settle over time. We recommend the owner monitor the boring site and backfill any settlement or depression that might occur, or provide fencing around the area of the boring locations to prevent trip and fall injuries from occurring near the area of any potential settlement.

Subsurface Exploration. In general, traffic control during our field investigation Our subsurface exploration will be conducted along the proposed alignment using signs, cones, and an arrow board in accordance with the WATCH manual. Our surface investigation will include consist of drilling exploratory boringsboring. The purpose of the borings will be to: ▪ Obtain subsurface information along from the pipe alignmentsite. ▪ Collect undisturbed and bulk samples of the various soil types for laboratory testing. As indicated in We propose the RFPfollowing field exploration plan. West of Proposed Building F (for Percolation Test) 1/10’ If refusal is encountered at a shallower depth than planned, we plan to drill a total of 6 borings. Based on the existing profile, depth to pipe invert will range from 25.0 to35.0 feet below existing ground surface. We plan drill the borings between 25.0 and 50.0 feet below existing ground surface or to refusal, whichever is shallowerwill be terminated at that depth. The borings will be drilled with a truck mounted rig (CME 75 or equivalent) equipped with 8-inch diameter hollow stem augers for soils sampling. Soils will be continuously logged and classified by the geologist/engineer in the field by visual examination in accordance with the Unified Soil Classification System. Undisturbed ring samples of the subsurface materials will be obtained at 5five-foot intervals, at changes in soil profiles, or where unusual conditions are encountered. The relatively undisturbed ring samples will be obtained using a Modified California Sampler (2.4-inch inside diameter and 3.0-inch outside diameter) lined with thin-walled sample rings. The sampler will be driven into the bottom of the borehole with successive drops of a 140-pound hammer falling 30 inches. The number of successive drops of the driving weight (“blows”) required for each 6 six inches of penetration will be shown on the boring log. The soil will be retained in brass rings (2.4 inches in diameter and 1.0 inch in height) and carefully sealed in waterproof plastic containers for shipment to the laboratory. Bulk samples of representative soil types will be collected in plastic bags from various depths bags. Groundwater levels, where encountered in the borings, will be recorded. Standard Penetration Test (SPT) will be conducted in the 50.0 feet deep borings starting at 20.0 feet below existing ground surface in accordance with ASTM D3550. Drive samples will be obtained using a 2.0-inch outside diameter and within 1.375-inch inside diameter split-spoon sampler at each sampling interval, the drive samplers will be fitted onto a 5-foot zone sampling rod, lowered to the bottom of the pipe elevationboring, and driven 18 inches or to refusal (50 blows per 6 inches) with a 140-pound free- falling hammer from a height of 30 inches using an energy-calibrated hammer delivery system. The soils recovered from the SPT sampling will be stored in sealed plastic bags to preserve the natural moisture content. Groundwater levels, where encountered in the borings, will be recorded. The borings will be backfilled with soil/cement soil cuttings and compacted by pushing down with augers using the drill rig weightaugers. The upper 1-foot will be filled with quick cement and the surface sprayed with black dye. If construction is delayedAs a result, the surface may settle over time. We If construction is delayed, we recommend the owner monitor the boring site and backfill any settlement or depression that might occur, occur or provide fencing protection around the area of the boring locations to prevent trip and fall injuries from occurring near the area of any potential settlement.