Study Of The Urban Deep Excavation Impact On Surroundings Environment

With the growth of the economy and the speeding up of urbanization, land for construction is more and more less. The construction of the city will have to develop toward the air and underground continuously, and the deep excavation engineering is applied more and more widely. But for the urban construction, most of the excavation engineering is located in the building concentration areas, having a very complicated surrounding environment. Excavation engineering is bound to bring some potential safety hazard to the surroundings. So safety problems of deep excavation and the impact on the surrounding environment has become the important research subject.In this paper, based on a Xi’an deep excavation engineering, the environmental effect of the urban deep excavation is systematic studied by the means of site monitoring and FEA numerical simulation.First, according to a concrete deep excavation engineering, the real-time monitoring is carried out for the whole process of deep excavation construction. The monitoring data is analyzed and processed to obtain the deformation rule of the horizontal displacement of pile top and the settlement of surrounding structure and the ground during the process of excavation. And then, the relationship between the horizontal displacement of supporting structure and the settlement of the surrounding ground and the structure is also studied. The working state of the foundation pit and surroundings environment is mastered timely to ensure the security of the surrounding environment of the foundation pit.Second, three dimensional finite element model of the foundation pit and its surrounding buildings is built through element analysis software MIDAS/GTS. Thedeformation law of the horizontal displacement of the retaining structure and the settlement law of the surrounding ground and buildings is mainly studied. Then by comparison the field measured results with the calculated results, the impact rules of the foundation pit excavation on the surrounding environment is analyzed to evaluate of the security of the surrounding environment.Last, the method of numerical simulation is used to calculate the horizontal displacement of the supporting structure and the settlement of the surrounding buildings under the condition of different design parameters of the pile-anchor supporting structure.The influence law of the stiffness of the supporting structure, the depth of the pile, anchor obliquity and anchor prestressing force on the deformation above is analyzed. And also,by using of gray correlation method, the effect of different design parameters is evaluated and compared to provide the reasonable suggestions for design parameters of supporting structure.Through the study of this paper, the valuable guidance and reference could be provided to the designing of supporting structure of similar deep excavation engineering and the protection of the surrounding environment.