200 W MARINE VIEW DR BAYWOOD Geotech Report 2025-08-11

October 16, 2020 Project No. T-8221 111 With a stable subgrade prepared as recommended,we recommend the following pavement section options: Light Traffic and Parking: g • Two inches of hot mix asphalt pavement(HMA)over four inches of crushed surfacing rock • Full depth HMA—3 ''A inches Heavy Traffic: ' • Three inches of HMA over six inches of crushed surfacing rock • Full depth HMAC—5 inches 111 For exterior Portland cement concrete (PCC)pavement,we recommend the following: ' • 6 inches of PCC over two inches of aggregate base o 28 day compressive strength—4,000 psi o Control joints spaced at a maximum of 15 feet Soil cement stabilization or constructing a soil cement base for support of the pavement section can also be considered as an alternate to the above conventional pavement sections. Assuming a properly constructed soil cement base having a minimum thickness of 12 inches and a minimum 7-day compressive strength of 100 pounds ' per square inch (psi), a minimum HMA pavement thickness of 3 inches would be required for the heavy traffic areas. The design of the soil cement base should be completed using samples of the subgrade exposed at the time of construction. The paving materials used should conform to the Washington State Department of Transportation (WSDOT) specifications for HMA, PCC, and crushed surfacing. 6.0 ADDITIONAL SERVICES Terra Associates, Inc. should review project designs and specifications in order to verify that earthwork and foundation recommendations have been properly interpreted and incorporated into project design. We should also provide geotechnical services during construction to observe compliance with our design concepts, specifications, and recommendations. This will allow for expedient design changes if subsurface conditions differ from those anticipated prior to the start of construction. ' Page No. 10