calculation of earth press coeff(seismic)
DESCRIPTION
calculation of earth pressure coefficientTRANSCRIPT
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Project Designed by: Anil
Client Ministry of Road Transport & Highway Checked by: S Rastogi
Job Name Date & Rev. 13-01-2015
Preparation of DPR for Dharasu - Gangotri Highway
Design of Abutment for Minor Bridge at 63+855KM
DYNAMIC INCREMENT OF EARTH PRESSURE DUE TO SEISMIC FORCE
Coefficient of Active Earth Pressure
Ka Dry = 0.297
Ka' Submerged = 0.308
Backfill Soil Parameter = 25 = 0.4363 Rad = 20 = 0.3491 Rad
= 10 = 0.1745 Rad = 0 = 0 Rad = 0 = 0 Rad
= 26= 26= 10
Abutment Length L = 12 mFooting Base width B = 9.50 m
Seismic Coefficients= 0.12= 0.08
Formula used For6.34 7.43 deg 0.11 0.13 Radians
6.59 7.7285 deg 0.12 0.13 Radians
Seismic case (Coefficent of Earth Pressure)For Seismic downward dry condition Ca 0.453 Ca = 0.453For Seismic upward dry condition Ca- 0.402For Seismic downward submerged conditioCa' 0.489 Ca' = 0.402For Seismic upward submerged condition Ca-' 0.432
Dynamic Increment of Earth pressure( Normal Case)
Ka = 0.297Ka' = 0.308 ###Ca = 0.453Ca' = 0.402
= 26= 26 ###= 10
= 20 deg ### 1= 10 deg
L = 12 m ###B = 9.5 m
= 0.156
Component Load Factor p h L F
m m KN m KN-m1 Earth Pressure 0.5 46.47 11.441 12 ### 5.72 18248.202 LL Surcharge 1 4.87 11.441 12 669.16 7.55 5052.90
o
o
submerged oo
o
dry KN/m3sat KN/m3sub KN/m3
h
v
+v -v +v -vdry = tan-1 h
1 v
submerged= tan-1 sat * h(sat - 1) (1 v)
dry KN/m3sat KN/m3sub KN/m3
submerged
Dynamic Increment of Earth Pressure (Ca-Ka)
Lever arm
(about base)
Moment MTT
KN/m2
2
2
2
)cos()cos()sin()sin(1
1*)cos(coscos
cos.cos).1(
ii
C va
EPSB_N