Analysis Of The Ground Surface Settlement Induced By Shield Construction

In recent years, the rapid economic development in our country, the city subwayconstruction investment actively, brought a series of practical problems of thecomplexity of the construction environment, on the choice of construction method,shield construction method with less effect on the surrounding environment and hasbeen more and more widely used. As the capital of Shaanxi, xi ’an in recent years rapidgrowth of economic strength, population explosion caused by the traffic problem isincreasingly significant, for city life bring a lot of the same, as soon as possible to solvethe traffic congestion problem is urgently needed. In many construction method,minimal impact of shield construction method for the ground buildings and relativelymature, which has been widely applied at present. Xi ’an is different from other kinds ofsoft soil area, the characteristic of the soil physical and mechanical properties of thesurface subsidence is difficult to accurately predict the influence of the northwesternregion is still at groping stage, during shield tunnel construction, excavation of thetunnel buried depth, radius and the construction technology and so on the many kinds offactors affecting the surface subsidence. At home and abroad on the upper surface is lessto consider the influence of the buildings, shield tunnel construction in the loess area,research on the influence of the surface subsidence is even more important, for laterdeveloping to provide certain reference in xi ’an subway.Xi ’an subway line2on the south wall section the influence factors of ground settlement caused by shield construction has carried on the preliminary discussion,simply summarizes the surface subsidence rule. Xi ’an is located in the loess area, theground settlement caused by shield construction in the region of impact studies wererare. Tunnel shield construction inevitably produces disturbance on the surrounding soil,thereby causing loss to the formation, which cause the surface subsidence, which isespecially important in subway construction and design. On the basis of the analysis offield measured data, this article selects the commonly used in the geotechnicalengineering numerical simulation software FLAC3D to real simulation of tunnelexcavation process, and considering the south wall constraints under the premise ofanalyzing the surface subsidence rule. This paper on the depth of lateral surfacesubsidence laws and different distribution of stiffness, longitudinal settlementdistribution, the wall effect on the surface settlement of shield method constructioncause, the relationship between surface subsidence and burial depth of the tunnel. Withanalysis, the comparison between the traditional Peck formula, consider the upperstructure stiffness correction method and the selection of parameters in numericalanalysis is proposed on the basis of settlement prediction formula, for other lines offuture design and construction has a certain reference value and engineeringsignificance.