ESBGU <br />pumping or deflection should be overexcavated and replaced with <br />compacted Base Aggregate. <br />Fine-grained soils may require moisture-conditioning prior to compaction <br />to adjust the natural moisture content to within ±2% of the optimum value. <br />Moisture conditioning may include ripping and aeration for soils too wet <br />or ripping and wetting if the soils are too dry. <br />Foundation Design and Construction (Driver Support Building) <br />4.Design the building using the seismic parameters and the response <br /> <br />spectra in Figure 4A. These seismic parameters correspond to <br />IBC2012/OSSC 2014 code requirements. <br />5.Design all footings using an allowable bearing pressure of 2,000 psf. This <br /> <br />value assumes the footings will be supported on a minimum of 6 inches <br />of Base Aggregate underlain by relatively undisturbed soil. The Base <br />Aggregate should extend at least 6 inches beyond the edges of the <br />foundations. <br />6.For sliding analysis, use a coefficient of friction of 0.5 between the <br /> <br />footings and the Base Aggregate. <br />7.Assume total and differential settlement will be ±½ inch and ±¼ inch, if <br /> <br />designed and constructed as recommended. <br />8.Use a modulus of subgrade reaction, ks, of 100 pci for slab design. This <br /> <br />value assumes that the slabs will be supported on a minimum of 12 inches <br />of compacted Base Aggregate underlain by firm subgrade. Reinforce all <br />slabs to reduce cracking and warping. Rebar, instead of wire mesh, is <br />recommended. The use of fiber as the sole method of reinforcement is <br />not recommended. <br />Foundation Design and Construction (Signal Pole) <br />9.Design the signal pole foundations according to ODOT Standard Drawing <br /> <br />TM653. The required foundation diameter and depths should be <br />established based on Table 1 of this report and the signal pole type. <br />10.The specifications for the signal pole foundation construction should <br /> <br />follow the requirements of Section 00512 of the Oregon Standard <br />Specifications for Construction (ODOT 2018a), supplemented by FHWA <br />(2010). <br />Santa Clara Transit Center January 15, 2019 <br />Geotechnical Investigation 9 Project 2181060 <br />Eugene, Oregon Rowell Brokaw <br />