2721 WETMORE AVE MARQUEE APARTMENTS 2023-06-28

Page 2 August 7, 2019 Martin soil nails on the North and South wails are design to support the full weight of the building without relying on the piles. 9) Soil Nail Design with Temporary Slope Cuts: Slope cuts are addressed in the previously submitted soil nail calculations for the East and West walls as input geometry. All surcharges above the slope cut are input as vertical loading. This is consistent with the SnailZ software. 10) Live Load Surcharges: See response to Items 3, 4 and 5 above, which are included in the previously submitted soil nail shoring calculations and summarized on Sheet SS4.1. STRUCTURAL 1) Geotechnical Report: See response from the Geotechnical Engineer who has reviewed our calculations and shoring drawings, and provided the reviewer with a copy of Figure 3. Please note that Figure 4 was not included because this project does not have soldier piles with multiple levels of tiebacks so it does not apply to this project. 2) Detail 4/SS4.0: Design criteria for initial lift vertical elements at north and south walls and vertical element corner piles have been coordinated with and reviewed by the geotechnical engineer. 3) Special Inspection,Testing and Geotechnical Observation Schedule: Schedule for shoring items has been added to the shoring drawings and clarifies geotechnical and special inspection items, including items with continuous or periodic inspection and welding inspection requirements. Note that for shoring installation, the geotechnical engineer acts as the licensed Nu- observer, that structural observation is not required. CTE will participate in responding to field questions as needed. Testing requirements for soil nails are detailed in Shoring Structural Note Sheet SS1.1. Note that the shoring system for this project is temporary. 4) Steel Construction: Noted. Please reference Sheet SS1.0 Shoring Structural Notes Section 00600 Materials for various steel materials used including nail tendons, VE piles, plates, nail grout, lean mix etc. Note most of requested information was included in the previously submitted notes and details. Requirements for welding is added as requested. Please reference Sheet SS1.1 for special inspection requirements including footnote 4 to 6. 5) Reinforced Shotcrete Construction: Noted. Please reference Sheet SS1.0 Shoring Structural Notes Section 00600 Materials for various concrete/shotcrete/grout materials used including Nail c, grout, Lean mix grout, rebar and WWF. Reference Section 00810 for shotcrete strength requirements. Splice requirements for rebar and for WWF are found in Detail 16/SS4.0. The shoring system is temporary support and does not require corrosion protection. 6) ASD design VS Strength Design for punching shear and bearing plates: Please note that FHWA NHI 14-007 does not require strength level (LRFD)design as the reviewer has suggested. Reference Section 5.3.1 which allows ASD design per previous edition, and Reference Table 5.1 "Minimum Recommended Factors of Safety for the Design of Soil Nail Walls Using the ASD Method." CTE previously submitted soil nail calculations met all required factors of safety of Table 5.1 using ASD design including punching shear bearing plate design. Table 5.1 was included in the calculations on Page 22 of 180. NOTE FHWA stated in Section 5.3.1 to paraphrase, the 2014 edition provides a strength (LRFD)design for Bridge related shoring as required by AASHTO, but allows ASD design as it fits past practice using ASD designs. Temporary excavations are not governed by AASHTO. SnailZ is an ASD design software so designing the bearing plates and facing using a consistent ASD design with factors of safety per Table 5.1 is acceptable per Section 5.3.1. The previously submitted calculations follow the previous editions of the FHWA reference for ASD design and comply with the 2014 Table 5.1 for ASD factors of safety of 1.5 or greater for punching shear and associated bearing plates as required. No additional calculations are required. 7) VERTICAL ELEMENTS: a) Please reference previously submitted South Soil Nail calculation pages 79 and 80 and North Soil Nail calculation pages 130 and 131 which clearly state that the small vertical element piles are used as a "belt and suspender"for initial lift of soil nails to mitigate settlement concerns. At the elevation of the existing footings, the soils are identified in the geotechnical a 3