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OCR for page 72
72 Symbols AE = Effective cross-sectional area of threaded anchors (or bolts) AH = Cross-sectional area of the connector head ahm = Cross-sectional area (per unit width) of mesh reinforcement in the wall facing, in the horizontal direction, at midspan between soil nails ahn = Cross-sectional area (per unit width) of mesh reinforcement in the wall facing, in the horizontal direction, at soil nail heads AHH = Total cross-sectional area of additional reinforcement (i.e., waler bars) in wall facing, in the horizontal direction and around soil nail heads AS = Cross-sectional area of headed-stud shaft At = Nail bar cross-sectional area AVH = Total cross-sectional area of additional reinforcement (rebar) in wall facing, in the vertical direction and around soil nail heads avm = Cross-sectional area (per unit width) of mesh reinforcement in the wall facing, in the vertical direction in the mid-span between soil nail heads avn = Cross-sectional area (per unit width) of mesh reinforcement in the wall facing, in the vertical direction over the soil nail heads C = Coefficient used for the estimation of the soil nail wall displacement CF = Factor that considers non-uniform soil pressures behind a soil nail wall facing and is used in the estimation of nominal resistances at the soil nail head CP = Factor that accounts for soil contribution to support and is used in the estimation of nominal resistances at the soil nail head D c = Effective, equivalent diameter of the potential slip conical failure in the facing around soil ′ nail heads DDEF = Horizontal distance behind soil nail wall where ground deformation can be significant DDH = Average diameter of soil nail drill-hole DE = Effective diameter of the core of a threaded anchor DH = Diameter of the head of a soil nail head connector (i.e., headed-stud) DS = Diameter of the shaft of a soil nail head connector (i.e., headed-stud) f c = Concrete compressive nominal resistance ′ = Yield tensile nominal resistance of soil nail bar fy fy-f = Yield tensile nominal resistance of reinforcement in facing fy-hs = Yield tensile nominal resistance of headed-stud in facing = Thickness of facing h H = Wall height

OCR for page 72
73 = Effective depth of potential conical slip surface forming in facing around soil nail head hc = Thickness of permanent facing hf = Thickness of temporary facing ht = Active earth pressure coefficient of soils behind soil nail wall KA = Soil nail length L = Bearing plate side dimension LBP = Pullout length extending behind slip surface LP = Length of headed-stud LS = Horizontal flexural resistance (moment per unit length) mid-span between soil nails mhm = Horizontal flexural resistance (moment per unit length) at soil nail head mhn = Vertical flexural resistance (moment per unit length) mid-span between soil nails mvm = Vertical flexural resistance (moment per unit length) at soil nail head mvn = Number of headed-studs in soil nail head connection NH = Number of threads per unit length in threaded anchor (i.e., bolt) nt = Nominal bond resistance of soil nails qU = Nominal resistance for flexure in facing RFF = Nominal resistance for tension of headed-studs located in facing RFH = Nominal resistance for punching-shear in facing RFP = Nominal pullout resistance of soil nails RPO = Nominal pullout resistance per unit length of soil nails rPO = Nominal resistance of a soil nail bar in tension RT = Horizontal spacing of soil nails SH = Spacing of headed-studs SHS = Vertical spacing of soil nails SV = Head thickness of headed-studs tH = Maximum load in a soil nail Tmax = Maximum load in the head of a soil nail To = Thickness of bearing plate tP = Punching-shear force acting through facing, around soil nail head VF α = Angle of batter of soil nail wall β = Backslope angle δh = Horizontal displacement at the top of a soil nail wall δv = Vertical displacement at the top of a soil nail wall φFF = Resistance factor for flexure in facing φFH = Resistance factor for facing headed-stud in tension φFP = Resistance factor for punching-shear in facing φPO = Resistance factor for nail pullout φT = Resistance factor for nail bar in tension γs = Unit weight of soil ρij = Reinforcement ratio in “i” direction (vertical or horizontal) and location “j” (at nail head “n,” or midspan “m” between soil nails) ρmax = Maximum reinforcement ratio in facing ρmin = Minimum reinforcement ratio in facing