1809 HOLBROOK AVE 2018-01-02 MF Import

Terhune Homes, Inc. February 25, 1999 Location of Minimum Fill Placement Relative Compaction Beneath footings, slabs 95% or walkways Behind retaining walls 90% 95% for upper 12 inches of Beneath pavements subgrade; 90% below that level Where: Minimum Relative Compaction Is the ratio, expressed In percentages, of the compacted dry density to the r aximum dry density, as determined in accordance with ASTM Test Designation D 1557-78 (Modified Proctor). Use of On -Site Soil JN 99028 Page 8 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 slightly silty and therefore moderately moistu,e sensitive. Grading operations will be more difficult during wet weather, or when the moisture content of this soil exceeds the optimum moisture content. Also, the grain -size distribution of the sand is relatively uniform but within a restricted range (fine- to medium - grained), which will increase the difficulty of achieving compaction. The moisture content of the 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 moisture content of the on -site soil was generally above the estimated optimum moisture content at the time of our explorations. The on -site sand underlying the topsoil could be used as structural fill, if grading operations are conducted during hot, dry weather, when drying the wetter soil by aeration is possible. During excessively 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. LIMITATIONS 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 are representative of subsurface conditions on the site. If the subsurface conditions encountered during construction are significantly different from those observed in our explorations, we should be advised at once so that we can review these conditions GEOTECH CONSULTANTS. INC. DAfj