Laserfiche WebLink
4.4 Structural Design <br /> The East Clearwell roof system and all roof system structural components shall be designed in <br /> accordance with IBC 2015 and all codes and standards referenced therein.Structural design shall <br /> be for Risk Category IV per Table 1.5-1,ASCE 7-10. <br /> Roof system structures shall be designed to withstand the following loads, at a minimum: <br /> • Dead load: Weight of all roof components and elements supported from the roof <br /> • Uniform Live load: 25 pounds per square foot <br /> • Concentrated Live Load:300 pounds on a one-foot square area <br /> • Snow load and frost depth:As specified by the City of Everett Building Department located at <br /> 3200 Cedar Street, Everett, WA <br /> o Contact person: Drew Martin at dmartin@everettwa.gov or(425) 257-8813 <br /> • Seismic and wind loads:As specified in the IBC 2015 and ASCE 7-10. <br /> The structural design shall not cause settlement or movement of the clearwell building structures <br /> and shall not cause leakage. <br /> To the extent that Design-Builder's design necessitates additional structural work on the clearwell <br /> building structure or foundations(for example additional columns, cross bracing, changes to existing <br /> clearwell walls or other changes, or seismic bracing of existing columns left unsupported as a result <br /> of Design-Builder's design), any such additional structural work shall be the responsibility of the <br /> Design-Builder and is included in the Contract Price. <br /> As part of its 50% design submittal, Design-Builder shall submit a stamped report from its structural <br /> engineer licensed as a Structural Engineer in the State of Washington,setting forth its structural <br /> analysis of the new roof system and its relationship to the existing clearwell structure.The analysis <br /> shall either: <br /> 1. State that no additional structural work to the East Clearwell, beyond the new roof system,will <br /> be required and demonstrate that the new roof system will not add vertical load or seismic base <br /> shear to the existing basin when compared to the current failed roof. (If new roof structure is <br /> lighter than the existing structures,the report shall also address any required detailing for wind <br /> uplift); or <br /> 2. If the new roof structure is heavier than the existing roof structures,the report shall address <br /> whether seismic upgrades to the East Clearwell building structures are needed per IBC 2015. <br /> The report shall also address any foundation issues resulting from the increased weight and <br /> shall detail all additional structural work(such as new or additional columns, cross-bracing, and <br /> modifications to the clearwell walls or foundations for example)that is included in the design of <br /> the upgraded system to address seismic,foundation and other structural concerns. <br /> 4.5 Acceptable Materials <br /> All materials shall be protected from corrosion by industry standard corrosion protection methods. It <br /> is expected that the headspace within the clearwell will be subjected to high humidity and <br /> chlorinated water. Materials shall meet the requirements of Table 4.2, below: <br /> City of Everett January 29,2020 <br /> Water Filtration Plant East Clearwell Roof Replacement DB Project Supplementary Conditions Page 8 <br />