Prediction model and application of three-dimensional ground surface settlement induced by tunnel excavation considering time effect

Abstract

It is difficult to consider the change of settlement along with time by using stochastic medium theory in the settlement prediction process in subway construction. A new settlement-time model is proposed. This model is based on normally distributed cumulative function. A prediction model of three-dimensional ground surface settlement considering time effect induced by subway tunneling is built up by using stochastic medium theory. The prediction formulae of ground surface settlement considering time effect induced by single tunnel and twin tunnels are deduced. The computing method of three-dimensional incline and curvature of the ground surface settlement considering time effect is presented. A case study of back analysis is presented based on the Dougezhuang-Heizhuanghu section tunnel project of Beijing subway construction. The results show that:The time-settlement model is close to the measured data,which proved the model is scientific; The model can make prediction of the spatial distribution and time variation of settlement; According by the predicted settlement surface,we can calculate the three-dimensional incline and curvature of the ground surface settlement,and obtain the differential settlement and shape of the surface settlement over time.

Keywords

• underground engineering
• ground surface settlement
• stochastic medium theory
• three dimensional ground settlement trough
• subway tunnel