Laserfiche WebLink
STRUCTURAL ANALYSIS FOR NEW PHOTOVOLTAIC SOLAR SYSTEM <br />NOTE: <br />THESE CALCULATIONS ARE BASED ON INFORMATION AND MEASUREMENTS PROVIDED BY THE CONTRACTOR FROM <br />HIS SITE INSPECTION. <br />3 Analysis of Existing Rafter Capacity:PV SOLAR ARRAY: GELVAN RESIDENCE <br />918 S. ELLIOT PLACE, SANTA ANA, CA 92704 <br />Rafter Loads: <br />Solar system dead load = 1211 lbs / 32 lag bolts total = 37.8 lbs at each lag bolt <br />Existing roof dead load = 14 psf <br />Snow load = 0 psf <br />Roof live load = 20 psf <br />Wind load = 114.2 lbs, 587.5 lbs <br />Rafter span = 7.0 ft <br />Load Combinations That Apply: <br />#1: D + Lr or S = 14 psf + 37.8 lbs at each lag bolt + 20.0 psf <br />#2: D + 0.75(0.6W) + 0.75(Lr or S) = 14 psf + 37.8 lbs at each lag bolt) + (0.75 (0.6) 114.2 lbs at each lag bolt) + <br />(0.75 ( 20 psf)) <br />#3: 0.6D + 0.6W = 0.6 ( 14 psf + 37.8 lbs at each lag bolt) - (0.6) 587.5 lbs at each lag bolt <br />Calculated Maximum Bending Moment: <br />#1: 208.3 ft/lbs + 66.2 ft/lbs = 274.5 ft/lbs <br />[( 34 psf) ( 7 ft^2)] / 8 = 208.3 ft/lbs <br />[( 37.84 lbs) ( 7.0 ft)] / 4 = 66.2 ft/lbs <br />#2: 85.8 ft/lbs + 66.2 ft/lbs + 90.0 ft/lbs + 91.9 ft/lbs = 333.8 ft/lbs <br />[( 14 psf) ( 7 ft^2)] / 8 = 85.8 ft/lbs <br />[( 37.84 lbs) ( 7.0 ft)] / 4 = 66.2 ft/lbs <br />114.2 lbs) ( 7 ft)] / 4 = 90.0 ft/lbs <br />0.75 [( 20 psf) ( 7 ft^2)] / 8 = 91.9 ft/lbs <br />#3: 51.5 ft/lbs + 39.7 ft/lbs - 616.9 ft/lbs = -525.7 ft/lbs <br />0.6 [( 14 psf) ( 7 ft^2)] / 8 = 51.5 ft/lbs <br />0.6 [( 37.84 lbs) ( 7.0 ft)] / 4 = 39.7 ft/lbs <br />0.6 [( 587.5 lbs) ( 7 ft)] / 4 = 616.9 ft/lbs <br />Section Required: 525.7 ft/lbs (12) (0.7) / 1518 psi = 2.9 cu in <br />Section Provided: 1.5 ( 3.5 ^2) / 6 = 3.1 cu in <br />3.1 cu in > 2.9 cu in, OK <br />Calculated Deflection: <br />[5( 34 psf / 12) ( 84 in^4)] / [384 (1200000) ( 5.4 )] = 0.29 in <br />Allowable Deflection: 84 in / 240 = 0.35 in <br />0.35 in > 0.29 in, OK <br />NOTICE: VISION CIVIL ENGINEERING: JENNIFER KEMME, PE <br />ANY CHANGES TO OR USES OF THESE DOCUMENTS 12273 11TH STREET, YUCAIPA, CA 92399 <br />WITHOUT THE WRITTEN CONSENT OF VISION 909.754.8300, JENKEMME@VISIONCE.COM <br />CIVIL ENGINEERING IS STRICTLY PROHIBITED. RCE 73054, EXP 12/31/24 <br />0.75 [(0.6)( <br />Prepared by JENNIFER KEMME 5/11/2023 Page 2 <br />918 S Elliot Pl <br />06/02/23