ENFORCE37590

• Permit No: M1977378
• IBM Index Class Name: Enforcement
• Doc Date: 11/17/2003
• Doc Name: Consent Decree 94CV5459
• From: Gold King Mines Corp.
• To: DMG
• Media Type: D
• Archive: No

Project As Built Koehler Tunnel Bulkhead By JFA Date 9/6/03
8.42' x 10.5' (12.04' Thick, Sta 3+02)
Sheet 1 of 6
References used:
Calculations arc based on:
Abel, J.F., Jr., Bulkhead design for acid mine draina¢,e: 1998, in Proc Westcm U.S. Mining-Impacted Watersheds,
Joint Conf on Remcdiation and Ecological Risk Assesment Technologies, Denver, CQ 36 p
American Concrete Institute, 1995, Building code requirements for structural concrete (ACI 318-95) and
commentary -ACI 318R-95: 369 p
Wang, C.K. & C.G. Salmon, 1985, Reinforced concrete design, 4th ed, Harper & Rowe Publishers, Inc.
Notation:
a =minimum concrete compression zone
depth (in) to balance rcbar tension
A , =area of rebaz (in3)
In uts:
Beam width, b w := 1 ft
Bulkhead depth below surface, B d := 225 ft
Maximum tunnel height, h := 10.5 ft
Maximum tunnel width, 1 := 8.42 ft
Design water head H := 497 ft
Concrete compressive strengtl~c := 3000 psi
Inbye line of sight water distance,S is := 2220 ft
Overburden rock density, y r := 164.6 pcf
Concrete density, y ~:= 150 pcf
Water density, y w := 62.4 pcf
Minimum concrete rbar cover,m c := 4.0 in
Rebar yield strength, f y := 60000 psi
Allowable pressure gradient with pressure
K = [3.5-25(M„/d)] p a := 41 psi
M =beam bending moment (ft-Ib) grouting of bulkhead/rock contact, 8
bw =beam width (1-ft)
B p =allowable breakdown pressure (psi)
d = max distance compressive fiber to rebar
center (in)
E ym =earthquake bulkhead mass (Ib)
E rm =earthquake static fluid load (lb)
fel =concrete tensile strength (3(f~)UZ]
f ~s = wncrete shear strength [2(f~)tn)
FS =factor of safety
L =bulkhead (beam) thickness (ft)
L s =bulkhead shear thickness (ft)
I =moment of inertia (in4)
M ~ =factored beam bending moment (ft-lb)
M n =nominal beam bending moment (ft-Ib)
M „a =earthquake beam bending moment (ft-]b)
Gravity acceleration, g := 32.2 ft/secz
Maximum credible earthquake acceleration, := 0.136 g
p =maximum hydraulic pressure head (psi) Bulkhead trial thickness, L t := 12.04 ft
pw =ratio of tensile reinforcement
S =section modulus (in3) Strength reduction factors
T =tensile bending force (16/ft) Rebar flexural tensile strength, ~ n := 0.90
U =factored required strength (Ib/ft)
Rebar reinforced concrete shear, ~ ~ := 0.85
U e =earthquake required strength (Ib/ft)
V =concrete sheaz strength (lb/ft) Plain concrete flexure strength, ~ pc := 0.65
Reinforced concrete flexural strength, rc := 0.85
gratdle.mcd A"I/190311:16 AM