Deformation Control And Numerical Analysis Of Deep Foundation Pit Monitoring

With the rapid development of China’s politics,economy and culture,the city’s functions have become more prominent.It has become an inevitable trend to carry out large-scale underground space development in urban centers where land is increasingly tense.More and more underground buildings are present in the world.In front of,such as underground parking lots,subways,civil air defense projects,etc.Due to the needs of economic development,its construction scale,excavation methods,and forms of support face severe challenges.In the development and utilization of underground space,there are often many uncertain factors.Due to the short study time of foundation pit engineering in China,the surrounding environment is complex,the excavation deformation has obvious spacetime effect,and it involves the interaction of complex retaining structure,foundation soil and surrounding structure,which makes the development of foundation pit space dangerous.The coefficient is large,the accident is frequent,and the compensation measures are difficult to solve engineering problems.Therefore,it is particularly important to carry out research on the foundation pit engineering.Based on the foundation pit engineering of Shenzhen Qianhai Hub,this paper firstly obtains the deformation law under various geological conditions by theoretical analysis of foundation pit deformation and excavation soil settlement,which lays a theoretical foundation for the numerical simulation analysis in Chapter 5.Then through the on-site implementation of monitoring feedback data,verify the results of numerical analysis,the three inter-connected,focusing on the soft soil area and close to the existing subway deep foundation pit excavation reinforcement area,studied the horizontal displacement of the wall top and The main law of land subsidence.The main work and conclusions of this paper are as follows:(1)The reinforcement method of “reinforcement around the ground wall and reinforcement in the pit” can meet the control requirements of the horizontal displacement of the ground wall during the whole excavation process.For the unreinforced soil,the x direction the reduction is 68% of the original and the y direction is reduced by 88%.(2)The maximum horizontal displacement depth of the retaining wall occurs at the excavation depth of 2/3m,which is located about 4m outside the reinforcement zone,and is stable between the two and three supports.The maximum settlement of the surface appears at about 6m behind the wall.(3)Comparative analysis of the measured values and calculated values of the horizontal displacement of the wall top,the surface settlement and the displacement of the subway line 11.The calculated values of the model symbols are basically consistent with the trend of the monitoring data,and have a good simulation effect.The information construction can be realized in the future foundation pit construction,and the deformation of the foundation pit is predicted to be a dangerous value to ensure the safety and stability of the foundation pit construction.And the safe operation of the subway.