The numerical simulation of the excavation shows that

for each basic deformation modes of the retaining wall

for example the forward rotation

reverse rotation and deflection

distribution of the ground surface settlement outside pit shows obvious regularity

which can be fitted by the exponential curve with a unified format

then the empirical formulas are got. Arbitrary deformation mode of the retaining wall can be fitted using the three basic deformation modes above

and the maximum displacement value for each basic deformation mode can be obtained. Using the empirical formulas above

the corresponding ground surface settlement for each basic deformation mode can be calculated. Then superimpose the settlement and obtain the distribution curve of ground surface settlement.