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 />1 Project Information:PV SOLAR ARRAY: NGUYEN RESIDENCE <br />Latitude 33.7402° deg N 509 S. STARBOARD STREET, SANTA ANA, CA 92704 <br />Longitude -117.942° deg W <br />Wind Speed 110 mph 95 mph (ASCE 7-16) <br />Wind Exposure C <br />Site Class D <br />Seismic Design Category D <br />2 Loads: <br />Existing Roof Dead Loads: <br />2 x 4 Trusses @ 24" OC 2.6 psf <br />1/2" Roof Sheathing 1.7 psf <br />Roof Felt 1.5 psf <br />Composition 5.0 psf <br />Miscellaneous 3.2 psf <br />Total 14.0 psf <br />Existing Snow Load:0.0 psf <br />Existing Roof Live Load:20.0 psf <br />Proposed Roof Live Load:20.0 psf <br />Wind Load: Using CBC 2019 (ASCE 7-16), Chapter 29: Wind Loads on Rooftop Equipment, the <br />following wind pressures were calculated. <br />p = qh (GCp) (ge) (ga) = 9.16 -47.13 psf <br />qh = 0.00256 Kz Kzt Kd Ke V2 = 19.64 psf <br />Kz = 0.85 (0-15 = 0.85, 20 = 0.90, 25 = 0.94, 30 = 0.98, 40 = 1.04) <br />GCp = 0.7 -3.6 (Roof pitch = 17 deg, Zone = 2, Aeff = 18.0 sf) <br />ge = 1.50 <br />ga = 0.80 <br />Lag Bolt Capacity: <br />5/16" lag bolt capacity = 270 lbs per inch embedment <br />With 2 1/2" minimum embedment, capacity = 675 lbs <br />Required Capacity: <br />47.13 psf * 21 modules * 18.0 sf = 17816.0 lbs <br />17816.0 lbs / 30 lag bolt connections = 593.9 lbs <br />The pull-out capacity of the 5/16" lag bolts with a minimum 2 1/2" embedment into the roof rafter is sufficient <br />to meet the demand of the wind uplift force on the solar system. <br />Seismic Load: Per the CEBC 2019 Section 503.4, if the demand-capacity ratio of the lateral load-carrying <br />elements increases less than 10% due to the addition of the solar system, no special provisions or structural <br />modifications are required. <br />Existing Roof Weight = 14.0 psf * 2490 sf = 34860 lbs <br />Weight of Solar System = 21 modules * 41.4 lbs + 189 lbs of racking = 1058 lbs <br />1058 lbs / 34860 lbs = 0.03 <br />The increase in load from the solar system will not increase the demand-capacity ratio of the existing lateral <br />load-carrying elements by over 10%. <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 12/31/22 <br />Prepared by JENNIFER KEMME 8/12/2022 Page 1 <br />509 S Starboard St <br />10/31/22