;AT Zl~.: U Design Maps Detailed Report <br />2012 International Building Code (44.010830N, 123.07728°W) <br />Site Class D - "Stiff Soil", Risk Category I/II/III <br />Section 1613.3.1 - Mapped acceleration parameters <br />Note: Ground motion values provided below are for the direction of maximum horizontal <br />spectral response acceleration. They have been converted from corresponding geometric <br />mean ground motions computed by the USGS by applying factors of 1.1 (to obtain SS) and <br />1.3 (to obtain S1). Maps in the 2012 International Building Code are provided for Site Class <br />B. Adjustments for other Site Classes are made, as needed, in Section 1613.3.3. <br />From Fig <br />ure 1613.3.1( <br />1) 1'I <br />Ss = <br />0.762 g <br />From Fig <br />ure 1613.3.1( <br />2) [2] <br />S, = <br />0.400 g <br />Section 1613.3.2 - Site class definitions <br />The authority having jurisdiction (not the USGS), site-specific geotechnical data, and/or the <br />default has classified the site as Site Class D, based on the site soil properties in accordance <br />with Section 1613. <br />2010 ASCE-7 Standard - Table 20.3-1 <br />SITE CLASS DEFINITIONS <br />Site Class VS N or Ncn S. <br />A. Hard Rock >5,000 ft/s N/A N/A <br />B. Rock 2,500 to 5,000 ft/s N/A N/A <br />C. Very dense soil and soft rock 1,200 to 2,500 ft/s >50 >2,000 psf <br />D. Stiff Soil 600 to 1,200 ft/s 15 to 50 1,000 to 2,000 psf <br />E. Soft clay soil <600 ft/s <15 <1,000 psf <br />Any profile with more than 10 ft of soil having the <br />characteristics: <br />• Plasticity index PI > 20, <br />• Moisture content w 40%, and <br />• Undrained shear strength s, < 500 psf <br />F. Soils requiring site response See Section 20.3.1 <br />analysis in accordance with Section <br />21.1 <br />For SI: 1ft/s = 0.3048 m/s 1lb/ft2 = 0.0479 kN/m2 <br />