5901 23RD DR W PROVIDENCE 2023-05-22

• • foundations and slabs-on-grade. Typical tilt-up buildings are required to comply with the standard and seismic reinforcement detailing requirements of ACI 318 based on the type of lateral system (i.e. , ordinary or special reinforced concrete walls) . The engineer should re-evaluate the building as needed. As stated in previous comments, full-size construction drawings should be submitted with clear construction-level details. Per comment 4a, if a building permit application is required, all structural modifications should be included in this drawing set, not the mechanical drawing set. The existing warehouse is primarily a 135' x 400' rectangle, with some bump outs. A lateral analysis of the tilt up wall/metal deck diaphragm for this rectangle is enclosed in the calculations. The panels requiring the penetrations are part of the shear wall system. The two panels receiving the penetrations have a shear force of 4.34 KLF,which is equal to 50 PSI which is below the threshold for shear reinforcement for f'c of 4,000. Typical tilt up mixes range from 4,000 to 6,000. The boundary of the panel next to the man door was checked and found to have 110 kips under the design event. This corresponds to 390 psi of compression in the tip with a tip element on the order of 6#7 bars within a closed tie. As the structural drawings were unavailable to us it is unknown what this tip element is, however even an 8 bar tip would be 24"long or less. Conclusion—the proposed hole occurs outside of a panel tip element in a panel not requiring shear reinforcement. Seismic forces for out of plane loads was found to be 0.4*W,for the 7-1/4"panel that is 35.35 PSF, 110 MPH Exp C wind is 27.0 PSF so seismic controls. Panel height at the opening is 27 feet, loaded at the 35.35 x 2' x 1.0/1.6 load factor adjust (LL vs E)found Mu =6.30 'k, a 7-1/4"panel,4,000 PSI with#5 @ 12"oc centered has Phi Mn of 7.73'k is satisfactory,is is agreed that the tilt up is probably heavier than this, but this is what needs to be replace at the hole. The taller panel is 27.0', review a 2 foot wide strip. The moment is 2 x 0.03524 x 27"2/8=6.42`k. Per the concrete spreadsheet#5 @ 12 has 2#5 located at centerline has a Phi Mn of 7.73 'k. On each side of the opening provide steel to replace this lost capacity that extends at least the reinforcement lap length, 26", past the opening each side. The reinforcement steel angles are to be GR 50, using ASD design for simplicity with Fb=33 KSI, providing a higher load factor than required (E=1.0 vs 1.5 LF of ASD). The required moment is 6.42 'k/2 members =3.21 `k,the required section is 3.21 x 12/33 = 1.167 in^3. A L5x3x1/4 has S=1.51 in^3 so fb=25.5 ksi—OK. See the Hilti printout for the anchors. 6. Fan EF-1 weighs 136 pounds and will be mounted overhead, representing a significant falling hazard. Support details capable of resisting vertical and lateral loading should be included in the drawings. The supports should be designed per ACSE 7-16 Chapter 13. Fan EF-1 is mounted within the 20.25 x20.25 cut out opening in the tilt up in a near balanced condition. The 136#is offset by the removal of 250 pounds of concrete. The five radiant heaters each weigh 130 pounds, details on M-2 show the hanging, the bracing cables, and the reinforcement of the roof deck where the 4"vent thimble occurs. Please contact me if you have questions. Thank you. G . B, F,GE WASy�NC z� i, 2< / W O 6721 w �4'CISTERE� 1� SS�ONAL ECG WASH CIVIL, MECH, & STRUCTURAL ENGINEER 12-4-22 John G. (Jay) Bartram S.E., P.E.