STRATA SUBSIDENCE CHARACTERISTICS OF SHIELD TUNNELING IN COASTAL SOFT SOIL AREA

In order to study the subsidence characteristics caused by large diameter shield tunneling in coastal soft soil area, based on project of North Oujiang tunnel Wenzhou City, displacement field, seepage field and stress surrounding rock during construction process under fluid-solid coupling were analyzed using finite difference method. The results show that when passes through monitoring section tunnel, a certain range this above will be uplifted. Shield tail grouting can effectively control settlement ground, increasing ground gradually decreases. With advance pore water pressure increases, layer rise sharply due grouting. When strata increases uplift extrusion, below decreases releasing. at is completed moves away from section, releasing decrease stratum shows funnel-shaped form.