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W HOPPER ENGINEERING ASSOCIATES <br />California License No.: 20498 <br />FAX: (310) 791-7308 <br />www.hopperenglneerlng.com <br />300 Vista Del Mar <br />Redondo Beach, CA 90277 <br />(310) 373-5573 <br />April 25, 2012 <br />VIA ELECTRONIC MAIL <br />Mr. Manny Huante <br />Stage-Plus <br />2330 South Susan Street <br />Santa Ana, CA 92704 <br />Subject:40'w x 40'd x 24'h Flat Textaline Stage Roof in Santa Ana, CA <br />Reference: Stage Plus Drawings for 40'w x 40'd x 24'h Roof from M. Huarte to W. Brown; <br />April 19, 2012. <br />Dear Mr. Huarte: <br />We have completed our analysis of the proposed roof structure as requested. <br />Here is a summary of our analysis and recommendations. <br />The roof structure consists of a 40 ft square x 24 ft high truss frame which is <br />fabricated entirely from 12 inch square welded aluminum box trusses. There are four (4) <br />columns at 40 ft centers which support four (4) roof beams bolted together at the end <br />plates and corner blocks via 5/8" Grade 8 bolts. The roof beams are covered with a light <br />textaline fabric roof which is 80% solid and weighs 150 lbs total. There are eight (8) guy <br />cables which secure the roof to four (4) ballast blocks on the ground, each weighing <br />4000 lbs. <br />There are two speaker arrays suspended from the downstage roof trusses <br />weighing 650 lbs each including the lift motors and.cables. The roof Frame lift motors <br />and cables which support the roof frame from the top of the columns weigh 600 lbs <br />total. <br />In order to assess the structural integrity of the system, we created a model <br />of the entire roof structure and columns as well as guy cables · using RISA-30, a <br />commercially available structural analysis program. We modeled all of the members as <br />composite members which reflect the overall mechanical properties of the 12" trusses to <br />get an accurate account of the structural behavior of the roof. We then applied the dead <br />and vertical rigging loads along with wind loads on the roof fabric and column trusses <br />equivalent to a 50 mph wind load in order to determine the structural integrity of the <br />roof system. <br />We have determined that the roof structure as shown on your drawings is <br />structurally adequate to support the proposed vertical rigging loads in addition to a 50 <br />mph wind load, which we feel is conservative due to the temporary duration of the <br />structure. <br />$ <br />, Ir-