2414 BAKER AVE 2017-01-13 - Laserfiche WebLink

Tom Eiden June 21, 2010 Use of On-Site Soil JN 10114 Page 12 If grading activities take place during wet weather, or when the silty, on-site soil is wet, site preparation costs may be higher because of delays due to rain and the potential need to import granular fill. The on-site soil is generally silty and therefore moisture sensitive. Grading operations will be difficult during wet weather, or when the moisture content of this soil exceeds the optimum moisture content. The moisture content of the silty, on-site soil must be at, or near, the optimum moisture content, as the soil cannot be consistently compacted to the required density when the moisture content is significantly greater than optimum. The on-site sands underlying the upper silty soils could be used as structural fill, if grading operations are conducted during dry weather. During excessively hot, dry weather, however, it may be necessary to add water to achieve the optimum moisture content. Moisture-sensitive soil may also be susceptible to excessive softening and "pumping" from construction equipment, or even foot traffic, when the moisture content is greater than the optimum moisture content. It may be beneficial to protect subgrades with a layer of imported sand or crushed rock to limit disturbance from traffic. Structural fill that will be placed in wet weather should consist of a coarse, granular soil with a silt or clay content of no more than 5 percent. The percentage of particles passing the No. 200 sieve should be measured from that portion of soil passing the three-quarter-inch sieve. LIM/TATIONS The conclusions and recommendations contained in this report are based on site conditions, as they existed at the time of our exploration and assume that the soil and groundwater conditions encountered in the test pits and hand borings are representative of subsurface conditions on the site. If the subsurface conditions encountered during construction are significantly different from tl�ose observed in our explorations, we should be advised at once so that we can review these conditions and reconsider our recommendations where necessary. Unanticipated soil conditions are commonly encountered on construction sites and cannot be fully anticipated by merely taking so;l samples in tesi pits and hand borings. Subsurface conditions can also vary between exploration locations. Such unexpected conditions frequently require making additional expenditures to attain a properly constructed project. It is recommended that the owner consider providing a contingency fund to accommodate such potential extra costs and risks. This is a standard recommendation for all projects. This report has been prepared for the exclusive use of the Tom Eiden, and his representatives, for specific application to this project and site. Our recommendations and conclusions are based on observed site materials. Our conclusions and recommendations are professional opinions derived in accordance with current standards of practice within the scope of our services and within budget and time constraints. No warranty is expressed or implied. The scope of our services does not include services related to construction safety precautions, and our recommendations are not intended to direct the contractor's methods, techniques, sequences, or procedures, except as specifically described in our report for consideration in design. Our services also do not include assessing or minimizing the potential for biological hazards, such as mold, bacteria, mildew and fungi in either the existing or proposed site development. GEOTECH CONSULTANTS, INC.