STUDY ON THE INFLUENCE AND DEFORMATION CONTROL MEASURES OF LARGE AREA UNLOADING ON EXISTING SUBWAY TUNNEL
Based on the project of an underground connecting channel and a river foundation pits in Hangzhou,this paper comprehensively analyzes the influence of large area unloading on the underground subway tunnel through design,construction,numerical simulation and monitoring measurement.The results show that the construction of the foundation pit across the existing subway does not simply cause the uplift deformation of the subway tunnel,the settlement deformation will also be caused by the site backfilling,pile foundation construction and soil reinforcement.The more complex the foundation pit condition is,the more complex the subway deformation will be.The author suggests that the design and construction of the foundation pit across the subway should be based on local conditions,and the construction process should be simplified as far as possible.In the construction of the foundation pit,the overall loading and unloading quantity above the subway should be controlled to achieve balance as far as possible.The excavation of foundation pit should be carried out along the direction perpendicular to the subway,the pit exposure time should be reduced,monitoring and feedback emergency mechanism should be strengthened.These measures can effectively reduce the influence of foundation pit excavation on the underground subway tunnel,and can be used as reference for similar projects in the future.
excavation of foundation pitload balancedeformation controltime-space effectnumerical analysis
万方数据
维普
