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<br />Project_Design Koehler Tunnel Bulkhead <br />8.5' x 9' (12' Thick. Station 3+02) <br />By JFA Date 7/2103 <br />Sheet 1 of 6 <br />References used: <br />Calculations are based on: <br />Abel, J,F., Jr., Bulkhead design for acid mine drainage: 1998, in Prot Western U.S. Mining-Impacted Watersheds, <br />Joint Conf on Remedia6on 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-95:369 p <br />Wang, C.K. & C.G. Salmon, 1985, Reinforced concrete design, 4th ed, Harper & Rowe Publishers, Inc. <br />Notation• <br />a =minimum concrete compression wne <br />depth (in) to balance rebar tension <br />A ~ =area of rebar (in3) <br />bw =beam width (1-ft) <br />B p =allowable breakdown pressure (psi) <br />d = max distance compressive fiber to rebar <br />center (in) <br />E b,,, =earthquake bulkhead mass (Ib) <br />E r,,, =earthquake static fluid load (lb) <br />fit =concrete tensile strength [3(f~tn] <br />f C8 =concrete shear strength [2(f~t~ <br />FS =factor of safety <br />L =bulkhead (beam) thickness (ft) <br />L a =bulkhead shear thickness (ft) <br />I =moment of inertia (in4) <br />M =beam bending moment (ft-Ib) <br />M a =factored beam bending moment (ft-Ib) <br />Inuuts: <br />Beam width, b w := 1 ft <br />Bulkhead depth below surface, B d := 225 ft <br />Maximum tunnel height, h := 9 ft <br />Maximum tunnel width, t := 8.5 ft <br />Design water head H := 497 ft <br />Concrete compressive strength;c := 3000 psi <br />Inbye line of sight water distance$ is := 2220 R <br />Overburden rock density, y r := 169.4 pcf <br />Concrete density, y c := 150 pcf <br />Water density, y K, := 62.4 pcf <br />Minimum concrete rebar cover,m c := 3.5 in <br />Reber yield strength, f Y := 60000 psi <br />Allowable pressure gradient with pressur P ;= ql psi <br />grouting of bulkhead/rock contact, ~ <br />Gravity acceleration, g := 32.2 ft/sec2 <br />M n =nominal beam bending moment (ft-Ib) <br />M ,,, =earthquake beam bending moment (ft-lb) Maxtmum credible earthquake acceleratioq := 0.136 •g <br />p =maximum hydraulic pressure head (psi) <br />pW = ratio of tensile reinforcement <br />S =section modulus (n3) <br />T =tensile bending force (lbfft) <br />U =factored required strength pb/ft) <br />U . =earthquake required strength (16/ft) <br />V =concrete shear strength (Ib/ft) <br />Bulkhead trial thickness, L t := 12 R <br />Strength reduction factors <br />Reber flexural tensile strength, ~ rt := 0.40 <br />Reber reinforced concrete shear, ~ rs := 0.85 <br />Plain concrete flexure strength, ~ pc := 0.65 <br />Reinforced concrete flexural strength, re := 0.85 <br />rueta~.~a irs~n 9m am rsr <br />