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Project Design Mogul Tunnel Bulkhead <br />10.6' x 9.5' (9' Thick. Station 2+41) <br />Notation continued: <br />V a =nominal concrete shear strength (Ib/ft) <br />V „ =factored concrete sheaz strength (lb/ft) <br />ve = rebar sheaz stress (psi) <br />W =total bulkhead load (lb) <br />Z =height of rock to prevent hydmfrac (ft) <br />~ avy =Overburden rock stress per ft of depth (psi) <br />w ~ =factored static fluid bulkhead load (psf) <br />w ~ =factored static fluid bulkhead earthquake <br />load (psf) <br />w uo =factored line of sight fluid bulkhead <br />earthquake load (psfj <br />w ~ =factored bulkhead concrete <br />earthquake load (psf) <br />a s =flexural stress (psi) <br />a m~ =maximum principal stress (psi) <br />a ,,,;,, =minimum principal stress (psi) <br />a ovb =overburden stress (psi) <br />By JFA Date 8/21/03 <br />Sheet 2 of 6 <br />Nuts continued: <br />Load increase factors <br />Fluid static load, ~ fs := 1.40 <br />Earthquake acceleration, static fluid ~ ge ;= 1.05 <br />load <br />Earthquake acceleration load, line of ~ ~ := 1.40 <br />sight <br />fluid and bulkhead masses, <br />Bulkhead lenztth for hydraulic pressure eradient: <br />Maximum pressure head, p := H Y w psi p = 94 psi <br />144 <br />Allowable pressure gradient of 41 psilft for low-pressure (~50 psi) grouting of upper part of <br />concrete/rock contact. <br />Required bulkhead length for low-pressure grouted concrete/rock contact := P L = 2.3 <br />41 <br />DCpth below surface to prevent hvdofrac of rock around tunnel: <br />Allowable formation breakdown pressure, B p := p B p, = 94 psi <br />T <br />Overburden pressure, per ft of of depth, ~ ovb '° 144 ~ ovb = 1.176 psi/ft <br />Height of rock to prevent hydrofrac, Z := p Z = 40.2 ft <br />2~~ ovb <br />R <br />