Evolution of soil pressure of prefabricated utility tunnel crossing activeground fissures in confined site
摘要
The underground utility tunnel is inevitably affected by ground fissures when crossing active ground fissures. The distribution of soil stress around the utility tunnel is studied through a large physical model test by monitoring the contact pressure between the soil and the structure around the utility tunnel. The monitoring positions are located at the bottom axis of the test box, bottom axis of the utility tunnel, bottom side line of the utility tunnel, side wall of the test box and top axis of the utility tunnel respectively. The results show that the cracks first appear near the preset ground fissure with a shear state, leading to tension state at the top face of soil. The effects of the deformation of the utility tunnel on soil stress are mainly concentrated at the end of the hanging wall and the position near the ground fissure. The stress state of the soil in hanging wall is relatively stable. However, the stress redistribution is mainly at the bottom of the utility tunnel, and the effects of the deformation of the utility tunnel on the surrounding soil decrease from the bottom axis to the sides gradually. The research results can be used for disaster prevention and foundation treatment of prefabricated utility tunnels in the areas with frequent ground fissure disasters.