A numerical study of the effect of groundwater movement on long-term tunnel behaviour

摘要

Soft ground tunnelling beneath the water table induces pore water pressure changes and alters the hydraulic regime in the ground. There are various factors that control the tunnel/soil interaction behaviour during the equilibration period after tunnel construction through to the long-term steady state. Through the presentation of results from coupled non-linear finite element analyses, this paper considers the differences in predicted ground and lining responses in the long term for different post- tunnelling flow conditions. A 4 m diameter circular tun- nel constructed 20 m below ground level is adopted for the geometry, with the soil conditions based on those found in London, UK, and Seoul, South Korea.