Sesearch Into The Effection Of Adjacent Building To Excavtion

With the rapid progress of urbanization, urban land increasingly tight, more and more new construction adjacent buildings.Therefore, in recent years, in engineering construction, which resulted in a large number of neighboring buildings on pit excavation and support of issues.With the complicated surrounding environment of the excavation, only intensity control can not meet the regulatory requirements for construction and excavation safety, at present, theoretical research of the excavation behind the practice requirements,calculation of deformation and destroyed computing theory and other aspects of earth pressure which adjacent buildings needs further study.On the one hand, ill-considered building on the excavation pit design, it will bring security risks;on the other hand, increasing the design overload value blindly, the program will cause unnecessary waste, a large number of similar problems encountered in foundation engineering practice.Therefore,this paper studies the impact on pit deformation and displacement of supporting structure and other factors caused by adjacent buildings and and analyze the deformation and failure mechanisms of the pit. Reasonable suggestions in the neighboring building excavation engineering design, while providing a reference conclusions in terms of the stability calculation and estimation deformation.First, the theoretical analysis and numerical simulation methods have been applied to the study of the distribution and factors of additional stress which generated by the building systematically in this paper, and determine the effective scope of the stress load on the building.On this basis, combined with engineering experience, in support of piling and excavation grading in two ways, using Midas / GTS simulation software,simulated envelope pressure and displacement, surface subsidence and uplift,Pit shear strain and changes in the plastic zone by selecting the load, change width, position and role of the basement depth factors adjacent buildings which caused by the excavation.It is found that the effects of soil properties on the building load stress distribution, mainly appeared in the change of stress diffusion angle.The distribution of the load stress is the critical factor for the safety and stability of the adjacent buildings. The properties of soil has little influence on the load stress distribution of buildings, and the influence of the building load value and the building’s location on the safety and stability of foundation pit is the most prominent. In this paper, based on the construction load stress distribution in accordance with the building load caused by the degree of deformation of the foundation pit for the division of the impact zone. Excavation of foundation pit in the dangerous area(d<0.5B), the influence of the building load on the foundation pit is very obvious; when the building and the pit distance in d>0.5B, the construction load has little influence on the foundation pit.In the pit design and construction process, we should fully consider the impact on the adjacent building excavation engineering,try to avoid the danger zone and the affected area of buildings, and to consider beneficial effects to the pit retaining structure of the basement and the pile foundation which in order to design safer, more economical and reasonable.