Research On Surface Settlement Law Caused By Construction Of Super Large Section Rectangular Pipe Jacking Tunnel

With the acceleration of China urbanization process,the development and utilization of underground space is more and more favored by builders.As a kind of trenchless construction technology,pipe jacking method is widely used in underground engineering construction.In order to improve the utilization ratio of underground space development,tunnel section is designed to be rectangular.For the excavation of super-large section rectangular pipe jacking tunnel,the disturbance of construction is greater,and the normal use of surrounding buildings is endangered.Therefore,it is of great significance to study the ground settlement caused by the construction of super-large section rectangular pipe jacking tunnel.This paper relies on Zhengzhou Shenzhuang North Road-Shangding Road underpass Zhongzhou Avenue tunnel project.Through the theoretical analysis,the measured data summary and the three-dimensional finite element numerical simulation method,the surface settlement caused by pipe jacking construction is studied.On the basis of this research,effective control measures are proposed to provide reference for the design and construction of the same or similar projects in Zhengzhou.The main research contents are as follows:(1)The principle and process of rectangular pipe jacking construction process are briefly analyzed and discussed.The causes of surface deformation,the characteristics of formation deformation,the mechanism of soil disturbance and the factors affecting surface settlement are analyzed.(2)The monitoring scheme of pipe jacking construction is studied,the measured data is analyzed in depth,and the general law of surface settlement is summarized.(3)The analysis model was established by MIDAS-GTS NX finite element software to analyze the surface settlement effects of soil pressure,elastic modulus,internal friction angle,top tube depth and grouting.(4)The failure mode of ground deformation caused by pipe jacking construction is discussed.Effective construction measures are put forward to control the ground settlement in a reasonable interval to ensure the smooth and safe advancement of the pipe jacking project.