6107 BERKSHIRE DR SEPA 016 - 041 Geotech Report 2025-04-14

Catholic Housing Services JN 16298 November 1, 2016 Page 4 concrete curing process. Water vapor also results from occupant uses, such as cooking and bathing. Excessive water vapor trapped within structures can result in a variety of undesirable conditions, including, but not limited to, moisture problems with flooring systems, excessively moist air within occupied areas, and the growth of molds, fungi, and other biological organisms that may be harmful to the health of the occupants. The designer or architect must consider the potential vapor sources and likely occupant uses, and provide sufficient ventilation, either passive or mechanical, to prevent a build up of excessive water vapor within the planned structure. Geotech Consultants, Inc. should be allowed to review the final development plans to verify that the recommendations presented in this report are adequately addressed in the design. Such a plan review would be additional work beyond the current scope of work for this study, and it may include revisions to our recommendations to accommodate site, development, and geotechnical constraints that become more evident during the review process. We recommend including this report, in its entirety, in the project contract documents. This report should also be provided to any future property owners so they will be aware of our findings and recommendations. SEISMIC CONSIDERATIONS In accordance with the International Building Code (IBC), the site soil profile within 100 feet of the ground surface is best represented by Site Class Type D (Stiff Site Class). As noted in the USGS website, the mapped spectral acceleration value for a 0.2 second (Ss) and 1.0 second period (Si) equals 1.39g and 0.52g, respectively. The site soils are not susceptible to seismic liquefaction because of their dense nature and/or the absence of near-surface groundwater. DRIVEN PIPE PILES Three-, 4-, or 6-inch-diameter pipe piles driven with a 850- or 1,100- or 2,000-pound hydraulic jackhammer to the following final penetration rates may be assigned the following compressive capacities. INSIDE FINAL DRIVING FINAL DRIVING FINAL DRIVING ALLOWABLE PILE RATE RATE RATE COMPRESSIVE DIAMETER (850-pound (I,IIIII-pound (2,000-pound CAPACITY hammer) hammer) hammer) 3 inches 10 sec/inch 6 sec/inch 2 sec/inch 6 tons 4 inches 16 sec/inch 10 sec/inch 4 sec/inch 10 tons 6 inches n/a n/a 10 sec/inch 20 tons Note: The refusal criteria indicated in the above table are valid only for pipe piles that are installed using a hydraulic impact hammer carried on leads that allow the hammer to sit on the top of the pile during driving. If the piles are installed by alternative methods, such as a vibratory hammer or a hammer that is hard-mounted to the installation machine, numerous load tests to 200 percent of the design capacity would be necessary to substantiate the GEOTECH CONSULTANTS, INC.