Laserfiche WebLink
CARUSO <br />TURLEY <br />SCOTT <br />structural <br />engineers <br />STRUCTURAL <br />ENGINEERING <br />EXPERTS <br />PARTNERS <br />Sandra Herd, SE, PE, LEED AP <br />Thomas Morris, SE, LEED AP <br />Richard Dahlmann, SE, PE <br />Troy Turley, SE, PE, LEED AP <br />Brady Notbohm, SE, PE <br />PROFESSIONAL <br />REGISTRATION <br />50 States <br />Washington D.C. <br />U.S. Virgin Islands <br />Puerto Rico <br />1215 W. Rio Salado Pkwy. <br />Suite 200 <br />Tempe, AZ 85281 <br />T: (480) 774-1700 <br />F: (480) 774-1701 <br />www.ctsaz.com <br />Date:June 5, 2024 <br />Mr. Ryan Heil <br />PanelClaw <br />1600 Osgood Street, Ste. 2023 <br />North Andover, MA 01845 <br />RE: Evaluation of PanelClaw system <br />Project Name: Santa Ana Dist Ctrl 1 <br />CTS Job No.: 24-0242-3039.1 <br />Per the request of Ryan Heil at PanelClaw, CTS was asked to review the <br />PanelClaw racking system with respect to the system’s ability to resist uplift and <br />sliding caused by wind and seismic loads. <br />Wind Evaluation: <br />PanelClaw has provided CTS with wind tunnel testing performed by CPP, Inc. <br />The system tested was the “clawFR 10 Degree” system. This system consists of <br />photovoltaic panels installed at a 10 degree tilt onto support assemblies. The <br />support assemblies consist of a support frame for the PV panels, wind deflectors <br />and areas for additional mass/weight as required for the ballast loads. <br />The wind tunnel testing was performed per Chapter 31 of ASCE 7-16. The <br />parameters of the testing were a flat roof system in both Exposure B and C on a <br />building with and without parapets. The testing has resulted in pressure and/or <br />force coefficients that were applied to the velocity pressure qz in order to obtain <br />the wind loads on the PV system. From the wind load results it is then possible to <br />calculate the ballast loads required to resist the uplift and sliding forces. <br />PanelClaw has provided CTS with the excel tool that was developed to obtain the <br />uplift and sliding forces. CTS has reviewed this tool and the wind forces obtained <br />to find that the amounts of ballast and mechanical attachments provided are <br />within the values required. Furthermore, CTS agrees with the methodologies <br />used to develop the uplift and sliding forces for the “clawFR 10 Degree” system <br />per the wind tunnel testing results. <br />Seismic Evaluation: <br />CTS was asked to review the PanelClaw system to determine attachments <br />required to resist seismic loading of the ballasted solar support system on the <br />roof of the existing building. Following CBC Load Combination 16-16 and ASCE <br />Section 2.4.5, the Dead Load value has been reduced by subtracting the vertical <br />component of the seismic forces (0.6*D - 0.14Sds*D). The contribution of friction <br />due to the component weight was not considered to resist lateral forces caused <br />by seismic loads per ASCE Section 13.4. <br />Utilizing this method, calculations have been provided for the number of <br />mechanical attachments that are required to resist seismic forces that are applied <br />to the system. <br />1895 & 1995 S Standard <br />Ave1/7/2025