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I It 1.3 / G iJ •r i v i i (, n
<br />Project, Steve Adit Bullhead, Sta. 2+65_
<br />10' Thick, 10' Wide, 1.0' High, #6 Rebar
<br />References Used:
<br />By ME L/JFA Date 10/30/07
<br />Shc;et 1 of 8
<br />Calculations are based on:
<br />Abel, J.F., Jr. Bulkhead-dc S1IIll for acid iiiine drainage: 1998, in Proc Western U.S. Mining-Impacted
<br />Watersheds, Joint Confon Remedincion and Ecological Risk Assessment'rechrnalogies, Denver, CO, 36 p
<br />American Concrete institute, 2002, Dui Idiniz code requirements for structural concrete (AC1 318-02) and
<br />commentary - ACI 318R-02: 369 p
<br />Wang, C.K. & C.G. Salmon, 1985. Reinforced concrete design: 4th ed., Harper & Roue Publishers, Tnc.
<br />Notation:
<br />a = minimum concrete compression zone
<br />depth (in) to balance rebar tension
<br />As = area of rebar (in2)
<br />b, = beam width (ft)
<br />Bt, = allowable breakdown pressure (psi)
<br />d = max distance, compressed concrete
<br />to center of tensile rebar (in)
<br />Eb,n = earthquake bulkhead load (lb)
<br />L-1in = earthquake static fluid load (i b)
<br />fcl = concrete tensile strength [3(f)112:?
<br />fu, = concrete shear strength [2(fc)1'2?
<br />FS = factor of safety
<br />L = bulkhead (beam) thickness (ft)
<br />Ls = bullhead shear thickness (ft)
<br />I = moment of inertia (in4)
<br />K = [3.5 - 2.5(M„/d)]
<br />M = beam bending moment (ft-lb)
<br />Mu = factored bending moment (ft-lb)
<br />Mn = nominal bending moment (ft-IL')
<br />M„a = earthquake bending moment (ft-lb)
<br />p = max hydraulic pressure head (psi)
<br />p,,v = ratio rebar to concrete areas = A,/(wbd)
<br />S = section modulus (in3)
<br />T = tensile bending unit force (lb/ft)
<br />U = factored unit strength required (1 b/ft)
<br />U, = earthquake unit strength reduired (lb/ft)
<br />V = concrete shear strength require) (lb/ft)
<br />Ynnuts;
<br />Beam width, b,A, := 1 ft (12 in)
<br />Bulkhead depth below surface, B,,, := 115
<br />Maximum bulkhead height, hb 10 ft
<br />Maximum bulkhead width, wb 10 ft
<br />Current tunnel heiglIt, ht 9 it
<br />Current tunnel width, wt 8.5 ft
<br />ft
<br />Design water head,, 120 ft
<br />Concrete compressive strength., fe - 3000 psi
<br />Inbye line-of-sight water distance, Sls := 280 ft
<br />Overburden rock density, 'I,, := 163 pcf
<br />Concrete density, 7, := 151 pcf
<br />Water density, 1'w := 62.4 pcf
<br />Minimum concrete rebar cover, me := 3.5 in
<br />Rebar yield strength, fy 60000 psi
<br />Pressure gradient with low-pressure
<br />Pag '- 41
<br />si
<br />concrete/rock contact grouting, p
<br />Gravity acceleration, &:= 32.2 ft/sect
<br />Maximum earthquake acceleration, a := 0.239' g
<br />Bulkhead trial thickness, Lt := 10 it
<br />Strength reduction factors
<br />Rebar flexure (tensile) strength, cps 0.90
<br />Reinforced concrete shear strength. c?,-s 0.75
<br />Plain concrete flexure strength, Opc 0.55
<br />Reinforced concretcc flexure strengtl: 0,•c := 0.90
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