Environmental Influence And Protection Due To Deep Excavation On The Construction Of Integrated Underground Building

On the city planning of shanghai, underground large integrated buildings will be constructed on the basis of subway station pivot. Because such underground integrated building are built in the downtown district of the city, where miscellaneous structures exist, the construction has unfavorable effect on surrounding environment. Environment protection has become an important problem in geotechnical engineering design and construction in cities. And deformation is the key to its success. It is urgent to search such subject to protect adjacent proper usage and its safety. The chief works are summarized as follows:(1) On the basis of measurement data, the rule of soil deformation due to excavation is studied. Through FDM (finite difference method) numerical simulation, the displacement field of deep excavation adjacent underground building with large stiffness is researched, and compare with general excavation to gain some valuable conclusion.(2) On the basis of analyzing and concluding relative study product all over the world by the numbers, some general problem on the construction of underground integrated building is studied.(3) On the basis of transitive law of displacement resulting from deep excavation, partition of approach zone, formula of partition of approaching zone ,influence coefficient of the formula are put forward.(4) Through large number excavation engineering experience on the construction of subway in Shanghai, measured data and theoretical analysis, corresponding relation is established between environment protection grade and partition influence coefficient, to help for later similar engineering to part influence zone and to estimate influence degree.(5) The mechanical behavior of buildings and underground pipeline in the condition of different settlement is very important to determine the standard of deformation controlling and measures for the engineering protection. The contribution of additional inner forces of bearing walls is studied. The general approach to analyze the buildings damage under the given ground settlement and the way to evaluate the building safety are presented. The influence of ration L/H (length and height of the wall in settling area) of the bearing wall in influent region, and the ration E/G etc. are researched according to different settle mode. Stress model of underground pipeline due to differential settlement is analyzed. Evaluation indicators of operating station, such as rail deformation, structure deformation, structure inner force, are compared compressively, and then are analyzed, unified and defined, to get the unification among indicators. The allowable settlement criteria of the all kinds of buildings are summarized.(6) The above research results applied to practical engineering, 3D finite element method is used to simulate the whole process of construction of shanghai stadium underpassing station, and safety appraisal is made.