Laserfiche WebLink
1. Ground barriers shall be approximately four feet (4')long,keyed at least one <br /> foot (1) into the trench wall and bottom, and spaced 10 feet upstream of each <br /> manhole for gravity sanitary sewers or every 400 feet on water lines and <br /> sanitary sewer force mains. <br /> 2. Ground water barriers shall extend to a point two feet (2')above the existing <br /> ground water level or one foot (1') above the bedding material which ever is <br /> greater. <br /> B. Over Depth Excavation <br /> 1. Restore over excavated subgrades to proper elevation with compacted <br /> stabilization material or compacted granular material. <br /> 3.05 BACKFILLING AND COMPACTION <br /> A. Backfill trench promptly after completion of pipe bedding. <br /> B. Deposit backfill material in uniform layers not exceeding eight inches in <br /> uncompacted thickness. Increased layer thickness may be acceptable provided it is <br /> demonstrated that the specified compacted density will be obtained. <br /> C. Use methods and equipment appropriate for the backfill material. Do not use <br /> equipment or methods that will transmit damaging shocks to the pipe. <br /> 1. Do not perform compaction by jetting or water settling. <br /> D. Import material for trench backfill if compaction can not be obtained with job <br /> excavated material or required by the City. <br /> E. Rock and bedrock encountered in the excavation shall be separated from other <br /> excavated material and legally disposed of properly by CONTRACTOR. <br /> F. Replace topsoil after construction and grading to the depth of stripping over all areas <br /> disturbed by construction operations and which will not receive other surface <br /> treatment. <br /> G. Obtaining a proper site for disposal of excavated rock and bedrock material, excess <br /> excavated materials, and material not suitable for backfilling is the responsibility of <br /> CONTRACTOR. <br /> 3.06 FIELD QUALITY <br /> A. Field Compaction/Moisture Control. <br /> 1. Field quality control compaction tests shall be conducted to determine <br /> compliance of compaction methods with specified density in accordance with <br /> ASTM D2922 (AASHTO T238) - Tests for Density of Soil and Soil - <br /> Aggregate In-Place by Nuclear Methods. <br /> Boyd Freeman Ditch Improvements 02320-9 Trenching,Backfrlling and <br /> August 2005 Compacting <br />