On 2nd November 2015 the supplement DIN 1054/A2:2015-11 with new partial safety factors for the seepage force in the framework of the verification of safety against hydraulic heave (HYD) has been introduced. These values are shown in the table below as well as the unchanged factors for permanent stabilising actions.
The validity of the design formula for determining the required embedded length of a construction pit wall in non-cohesive soil developed by Dr. Aulbach remains unaffected by this amendment. The implemented factor of the required global safety ηi allows to consider any safety level. In this connection ηi will be generated as the quotient of the partial safety factors for seepage force γH and permanent stabilising actions γG,stb respectively as a function of the design situation.
Thus according to the current amendment DIN 1054/A2 the formula named above has to be modified by inserting the value
for the required global safety in the transient design situation for favorable soil.
The design-tool HYD basing on the formula named above enables a fast and simple determination of the required embedded length and is still available for free. Request here if you are interested – keyword: formula.