2007-11-16_REVISION - M1977300 - Laserfiche WebLink

Home Browse Search

11/13/2007 13:57 FAX Project, Steve Adit Tunnel BuIldie id. Sta. 2+65 10' Thick, 10' Widc, 101 Rich, #6 Rebar Notation continued: Vn = nominal concrete shear strength (lb/ft) V, = factored concrete shear strength (lb/ft) V.4 = rebar shear stress (psi) W = total bulkhead load (lb) Z = height of rock to prevent hydroli-ac (ft) Aovb = overburden rock stress per ft depth (ft) coj, = factored static fluid bulkhead load (psf) = factored static fluid bulkhead earthquake load (psf) coin = factored line-of=sight fluid earthquake bulkhead load (psf) Wtbe = factored concrete bulkhead earthquake load (psf) ? 0121018 By M EL/JFA Date 10/30/07 Sheet 2 of 8 Inputs continued: Load inereasi design factors fluid static load, ?F., := 1.40 Earthquake acceleration cf static fluid epfc := 1.05 load, Earthquake acceleration of line-of-sight OL.a 1.40 impounded 17uid and F. ullchead loads, v„ i = nominal limiting shear stress, wb/Lt<2 (psi) vie = nominal limiting shear stress, wb/L,= 2-5 (psi) a'y = flexural st•1•ess (psi) amingh = tniminum conuict grout pressure (psi) c,,,aNgp = maximum conurct grout pressure (psi) Bulkhead length for allowable hydraulic pressure Gradient: H --1,, Maximum (design) hydraulic pressure, p := 144 psi p = 52 psi B w''?I w Minimum contact grout pressure, Umingp := 144 psi Cymingp = 49.8 psi 2 ' Bw•1'r Maximum contact grout pressure, Urnaxgp :_ 144 psi Qmaxgp 260 psi = Allowable 41 psi/ft pressure gradient for low-pressure grouting of upper part of concrete/rock contact: Required bulkhead thickness for low-pressure contact grouting, L11i, := 1 ft L1,p = 1.27 ft Depth below surface to prevent hvdrofrac of rock around tunnel: Available formation breakdown pressure, Overburden pressure, per ft of depth, Height of rock to prevent hydrofrac, BP p Dovb 144 Z BP 2•Dovb 131, = 52 psi da,,b = 1.132 psi/ft Z=23 ft