Research On The Subsidence Of Ground Caused By Pipe Jacking Construction

With the accelerating urbanization process, the underground space development and utilization of by people more and more attention. As a kind of trenchless construction technology, pipe jacking method is widely used in underground engineering construction, and achieved good environmental and economic benefits. In view of the features of the pipe jacking method itself, its construction process can produce disturbance on the surrounding soil, resulting in deformation of surface of the earth around it. If too large, the deformation of the hazards around roads, buildings, structures and the security crisis. So the deformation caused by pipe jacking construction has the very vital significance.The pipe jacking construction method by the use of Zhengzhou new district sewage treatment plant project off-site trunk sewer project as the background, first of all, according to the formation condition and working condition, the top of this pipe jacking project into theoretical calculation parameters. Secondly, through the theoretical calculation of the surface deformation value and numerical simulation were compared with monitoring deformation value of the data, it is concluded that this type of area caused by pipe jacking construction deformation law and influence scope. Finally, to reduce environment impact caused by pipe jacking construction reasonable control measures are put forward and the suggestion, provide a reference basis for future similar pipe jacking project.In this paper, the main contents and conclusions are as follows:(1) according to the WA line 35 #~36 # well section of the formation condition and working condition of jacking process of jacking force, relay between the position and number of construction parameters, such as theoretical calculation.(2) the poisson’s ratio of soil oval than equivalent radial deformation mobile pattern on the surface, the influence of this engineering construction using the adjusted Sagaseta formula calculated caused by the ground horizontal, vertical scope, summarizes the excavation surface position influence on surface subsidence laws. Analysis of different buried depth, radius, and the influence of strata subsidence over the ground loss rate table.(3) by using the finite element software, the simulation pipe jacking construction influence on surface subsidence, and analyze the elastic modulus and internal friction Angle on the calculation of the influence of the settlement.(4) through theory, finite element simulation results and experimental data analysis, it is concluded that this kind of parts surface deformation caused by the pipe jacking construction of transverse impact range(axis centered around the 1.5 h to the pipe axis depth); Excavation plane arrived at different positions along the axis of the longitudinal impact range for –2h ~ 2h(negative on behalf of the excavation face away from the monitoring cross section, and just said excavation face did not reach the monitoring cross section), it is concluded that this kind of formation of pipe jacking construction take 1.5% of the stratum loss rate on the surface subsidence prediction, has certain reference significance.(5) to reduce ground deformation and environmental hazards caused by pipe jacking construction effective control measures are put forward.