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Mr. Drew Martin,PE,SE <br /> October 8,2019 <br /> 2190664.20 wel <br /> Page 2 of 3 <br /> b. The modified wall panels shall not be considered as part of the LFRS if they do <br /> not satisfy the reinforcement requirements of ACI 318-14 Sections 18.10. <br /> Documentation substantiating compliance with this section shall be submitted for <br /> review. See IBC Section 1901.2. <br /> Response: Existing wall panels are still well within acceptable loading for the <br /> original special concrete shear wall requirements. <br /> c. Continuing with the previous comment, modifications to the diaphragm system <br /> may be required if the modified walls are not adequate to perform as part of the <br /> LFRS. Calculations and details for diaphragm modifications shall be submitted <br /> for review as needed. See IEBC Section 807.2. <br /> Response: Existing diaphragm is not affected. No changes required. <br /> 2. The HSS girts per Elevation 1/S1.1 appear to require three connections at the top and <br /> bottom per Section 2/S1.1, with the bottom connection located within 3-1/2 inches of the <br /> bottom panel edge. The structural calculations do not consider this edge distance. <br /> Revised calculations substantiating the design including all edge distances shall be <br /> submitted for review. See IBC Section 1604.1 and 1901.2, and ACI 318-14 Section <br /> 17.7. <br /> Response: The existing wall panels continue 3' below finish slab so no <br /> modification required. <br /> 3. The HSS girts per Elevation 1/S1.1 change to out-of-plane load path from uniform to <br /> concentrated loads between the wall panels and the supporting foundation and roof <br /> diaphragm. Revised connections shall be provided at the top and bottom of the panels <br /> to the supporting structure. The diaphragm connection shall be designed for forces per <br /> ASCE 7-10 Section 12.11.2.1; ka per Equation 12.11-2 shall consider the diaphragm <br /> span between supporting walls, not the width of the modifications or the spacing of the <br /> girts. The roof diaphragm shall be modified to provide subdiaphragms as needed to <br /> develop the connection load into the diaphragm. See IBC Sections 1604.1, 1604.4, and <br /> 1613.1. <br /> Response: The out of plane, panel-to-roof load, and the panel connections to roof <br /> joist have not changed. The strong backs are maintaining the out-of-plane <br /> bending strength of the panel between the roof joist and the foundation. There <br /> are no changes that have altered the load path. No changes required. <br /> 4. Section2/S1.1 shows the typical girt connections to the existing concrete wall panels <br /> utilizing expansion anchors. See IBC Section 107.2.1. The following comments shall be <br /> addressed. The connection design is based on a minimum panel edge distance of 7-1/2 <br /> inches. This distance shall be specified. <br /> Response: The edge of panel distance has been adjusted and called out. <br /> a. The section specifies a minimum embedment of 4-1/2 inches. This is the <br /> effective depth after installation and tightening. However, the nominal anchor <br /> depth (i.e., minimum hole depth and anchor length prior to tightening) per the <br /> A © O <br />