DESIGN SPECIFICATIONS FOR HIGHWAY BRIDGES - IISEE

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8.3.2 Calculation of Lateral Force on Foundations by Liquefaction-induced Ground Flow Force When considering the effects of liquefaction-induced ground flow, lateral movement forces acting on pier foundations shall be obtained as below: In the case where lateral movement occurs under the conditions shown in Fig. 8.3.1, lateral movement forces per unit area calculated by Equations (8.3.1) and (8.3.2) shall be applied to structural members in the non-liquefying layer and those in the liquefying layer, respectively, both of which are located above the depth in consideration of the effects of lateral movement. In this case, the horizontal resistance of the soil layer within the thickness necessary to consider the effects of lateral movement cannot be expected. q NL =c s c NL K p γ NL x (0≦x ≦H NL ) ・・・・・・・・・・・・・・・・・・・・ (8.3.1) q NL =c s c L { γ NL H NL +γ L (x-H NL ) } (H NL < x ≦H NL + H L ) ・・・・・・・・・・・・・ (8.3.2) where q NL : Lateral movement force per unit area (kN/m 2 ) acting on a structural member in a non-liquefying layer at the depth x (m) q L : Lateral movement force per unit area (kN/m 2 ) acting on a structural member in a liquefying layer at the depth x (m) c s : Modification factor on distance from the water front. CS shall take a value shown in Table 8.3.1. c NL : Modification factor of the lateral movement force in a non-liquefying layer. CNL shall be a value in Table 8.3.2, according to liquefaction index PL (m 2 ) obtained from Equation (8.3.3). P L 0 20 1 F 10 0.5xdx ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ (8.3.3) L CL : Modification factor of the lateral movement force in a liquefying layer (can be taken as 0.3) Kp: Passive earth pressure coefficient (in normal condition) γ NL : Mean unit weight of a non-liquefying layer (kN/m 3 ) γ L : Mean unit weight of a liquefying layer (kN/m 3 ) x : Depth from the ground surface (m) H NL : Thickness of non-liquefying layer (m) 41
H L : Thickness of liquefying layer (m) F L : Liquefaction resistance factor calculated by Equation (8.2.1). If FL ≧1, FL = 1 . Non-liquefying layer Thickness necessary to consider the liquefaction-induced ground flow effects Liquefying layer HL Thickness unnecessary to consider the liquefaction-induced ground flow effects Non-liquefying layer Fig.8.3.1 Model for Calculating Lateral Movement Force Table 8.3.1 Modification Factor Cs on Distance from Water Front Distance From Water Front s (m) Modification Factor cs s≦50 1.0 50
Page 1 and 2: DESIGN SPECIFICATIONS FOR HIGHWAY B
Page 3 and 4: 6.3 Verification of Seismic Perform
Page 5 and 6: 12.6 Design of Members of Pier Foun
Page 7 and 8: construction site, and is normally
Page 9 and 10: Chapter 2 Basic Principles for Seis
Page 11 and 12: Chapter 3 Loads to be considered in
Page 13 and 14: Table 4.2.1 Standard Acceleration R
Page 15 and 16: 4.4 Modification Factor for Zones M
Page 17 and 18: Chapter 5 Verification of Seismic P
Page 19 and 20: Chapter 6 Verification Methods of S
Page 21 and 22: T 2.01 ・・・・・・・・
Page 23 and 24: 6.2.5 Seismic Hydrodynamic Pressure
Page 25 and 26: Ground Surface Average Section Fig.
Page 27 and 28: Table 6.3.1 Standard Values of the
Page 29 and 30: 6.4.3 Design Horizontal Seismic Coe
Page 31 and 32: khc0 : Standard value of the design
Page 33 and 34: 6.4.6 Performance Verification for
Page 35 and 36: the shear strength based on Section
Page 37 and 38: Chapter 7 Verification Methods of S
Page 39 and 40: 2) Steel piers and steel superstruc
Page 41 and 42: Chapter 8 Effects of Seismically Un
Page 43 and 44: k hg : Design horizontal seismic co
Page 45: design shall be assumed to be actin
Page 49 and 50: (6) When an isolation bearing is us
Page 51 and 52: 9.3.3 Equivalent Linear Model of Is
Page 53 and 54: 9.4 Basic Performance Requirement f
Page 55 and 56: 10.2 Evaluation of Failure Mode, La
Page 57 and 58: 10.3 Calculation of Lateral Strengt
Page 59 and 60: Horizontal force P Horizontal displ
Page 61 and 62: d : Effective length (mm) of latera
Page 63 and 64: 10.6 Structural Details for Improvi
Page 65 and 66: h i = h M yi 1 D ・・・・
Page 67 and 68: 1.0 on the effects of alternative c
Page 69 and 70: (2) Failure mode of an Reinforced C
Page 71 and 72: Chapter 11 Verification of Seismic
Page 73 and 74: Chapter 12 Verification of Seismic
Page 75 and 76: 12.5 Ductility and Displacement Cap
Page 77 and 78: 13.5 Design of Members of Abutment
Page 79 and 80: 14.3 Reinforced Concrete Superstruc
Page 81 and 82: Girder Girder Girder Pier Fig. 14.4
Page 83 and 84: Chapter 15 Verification of Sesmic P
Page 85 and 86: horizontal seismic coefficient spec
Page 87 and 88: provided in Section 6.3.3. Rd : Dea
Page 89 and 90: a skew bridge or a curved bridge, t
Page 91 and 92: length of the unseating prevention

DESIGN SPECIFICATIONS FOR HIGHWAY BRIDGES - IISEE

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