# Retaining wall Formulae Sheet

```Retaining walls- Stability Analysis
Earth pressure
Pπ = qHKπ
1
Pπ = πΎ!"#\$ H ! Kπ
2
1 β sin β
πΎπ =
1 + sinβ
πΎπ = cosπ½ ×
!"#!! !"# ! !!!"# ! β
!"#!! !"# ! !!!"# ! β
Sloping surface Pπ = qHKπ
1
Pπ = πΎ!"#\$ H ! Kπ
2
1 β sin β
πΎπ =
1 + sinβ
πΎπ = cosπ½ ×
!"#!! !"# ! !!!"# ! β
!"#!! !"# ! !!!"# ! β
π = ππππ × πΎ!"#!. π! = π! sin π½
π! = π! cos π½
Sloping surface Overturning moments
FOS =
!"# !" !!! !"!#\$%& !!!" !"#\$#% !"#\$%&\$'(')
!"# !" !"#\$%&\$'(') !"!#\$%&
π!
β₯2
π!
Factor of safety against Sliding
FOS =
!!
!!
β₯ 1.5
πΉ! = πΆ! π΅ + π! tan πΏ + π!
π! = π! + π!
π! = total vertical force
πΏ = πππππ ππ π€πππ πππππ‘πππ
πΆ! = π’πππ‘ ππ ππβππ πππ
=
!!
!"
Factor of safety against base pressure
X = = βπ! β βπ!
π!" + βπ!
π = π < !
!
- X
π΅
6
π!
π!
π! β€ = πΉ!
3
π!
6π
6π
π! = 1+
= π! 1 +
π΅
π΅
π΅
π! = π!
6π
1β
π΅
π!
π! = = πππππ€ππππ πππππππ ππππ π π’ππ
π΅
π! = π’ππ‘ππππ‘π πππππππ πππππππ‘π¦
```