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Project Design Mogul Tunnel Bulkhead <br />8' x 8' (9' Thick, Station 2+411 <br />References used: <br />By JFA Date 7/4/03 <br />Sheet 1 of, <br />Calculations aze based on: <br />Abel, J.F., Jr., Bulkhead design for acid mine draina¢e: 1998, in Proc Wcstem U.S. Mining-Impacted Watersheds, <br />Joim Cmif on Remediation and Ecological Risk Assesment Technologies, Denver, CO, 36 p <br />American Concrete Institute, 1995, Building code requirements for structural concrete (ACI 318-95) and <br />commentary -ACI 318R-9S: 369 p <br />Wang, C.K. & C.G. Salmon, 1985, Reinforced concrete design, 4th ed, Harper & Rowe Publishers, Inc. <br />Nota6on• <br />a =minimum concrete compression zone <br />depth (in) to balance rcbar tension <br />A , =area of rcbar (ins) <br />b,,. =beam width (I-ft) <br />B p =allowable breakdown pressure (psi) <br />d = max distance compressive fiber to rebaz <br />center (in) <br />E nm =earthquake bulkhead mass (lb) <br />E t,„ =earthquake static fluid load (Ib) <br />fit =concrete tensile strength [3(f~)tn] <br />f ~s =concrete shear strength [2(f~)tn) <br />F S = factor of safety <br />L =bulkhead (beam) thickness (ft) <br />L , =bulkhead shear thickness (ft) <br />I =moment of inertia (in4) <br />1VI =beam ben~:ug moment (ft-ib) <br />Inputs: <br />Beam width, b w := I ft <br />Bulkhead depth below surface, B d := 137 ft <br />Maximum tunnel height, h := 8 ft <br />Maximum tunnel width, 1 := 8 ft <br />Design water head H := 218 ft <br />Concrete compressive strengtl~c := 3000 psi <br />Inbye line of sight water distance$ is := 420 ft <br />Overburden rock density, y r := 173 pcf <br />Concrete density, y c := 150 pcf <br />Water density, y w := 62.4 pcf <br />Minimum concrete rbar cover,m ~ := 3.S in <br />Rebar yield strength, f Y := 60000 psi <br />Allowable pressure gradient with pressur P ;= 41 psi <br />^routine of i ::": head/rock contact. ~ <br />M „ =factored beam bending moment (ft-lb) Gravity acceleration, g := 32.2 ft/sec2 <br />M„ =nominal beam bending moment (ft-Ib) <br />M „~ =earthquake beam bending moment (ft-lb) Maximum credible earthquake acceleratiot; := 0.094•g <br />p =maximum hydraulic pressure head (psi) Bulkhead trial thickness, L t := 9 ft <br />p,,. = ratio of tensile reinforcement <br />S =section modulus (n3) <br />T =tensile bending force (Ib/ft) <br />U =factored required strength (16/ft) <br />U a =earthquake required strength (16/ft) <br />V =concrete shear strength (16/ft) <br />~~- <br />Strength reduction factors <br />Rebar flexural tensile strength, ¢ rt := 0.90 <br />Rebar reinforced wncrete shear, ~ ~ := 0.85 <br />Plain concrete flexure strength, ~ ~ := 0.65 <br />Reinforced concrete flexural strength, re := 0.85 <br />';"~ <br />t~emim evtut9mtiuett <br />