Research On The Impact Of Hefei Subway Construction To The Formation And Adjacent Piles Foundation

Along with the rapid developing economy of our country in recent years, urban construction with each passing day, At present, large crowds of people move into cities, making them bigger and bigger, because of the conflicts between increasing population and shortage of urban area, hat lead to the urban traffic pressure. In order to alleviate traffic pressure, subways are in construction or to be constructed in many Chinese cities to mitigate traffic jam. Due to high automation, little interference many other advantages, shield tunnel is applied to the more surface buildings and traffic and and more extensively. However, the surrounding environment is complex, adjacent high-rise buildings and viaduct, that led to close the underground structure construction. Shield excavation process will inevitably produce disturbance of surrounding soils, leading to the surrounding building foundation to generate additional deformation and internal force of the impact tends to lead to unpredictable disasters. So, construction process to carry out the monitoring work, and study of shield tunneling on the influence of building pile foundation and the surrounding environment has important significance.This paper takes Hefei subway line one between Taihu road Station and Nanyihuan Station shield tunneling construction engineering as background,according to current situation of construction and research. Using the finite difference software Flac3D numerical analysis. By means of combining field monitoring and numerical simulation, study the ground settlement caused by shield excavation and its influence on adjacent pile foundation deformation.The article main work includes:1. In this paper, the exordium introduces the current achievement on this subject. And expounds the shield excavation leads to the surface and the basic theory of pile foundation deformation as well;2. Combined with hefei complex geological conditions to research on soil deformation law of shield excavation process by using the finite element software Flac3D to establish the three-dimensional model of tunnel excavation. Illustrates different propulsion, excavation speed and grouting lag of the impact of land subsidence;3. To set up the road, bridge foundation, surrounding rock interaction of the three dimensional finite element model by Flac3D. Through the refinement of numerical simulation, and combining with soil, material nonlinearity, lining-surrounding rock pile soil contact, to studied in the process of shield tunnel excavation adjacent pile foundation the working performance of the general changing laws;4. By collating the construction monitoring data, draw the corresponding laws. Compared with the results of numerical simulation, to verify the feasibility of the numerical simulation prediction of shield excavation effect. Use has been construction experience, further put forward the corresponding safety control measures and Suggestions.