The Collapsibility Of Loess Ground Deformation And Subsidence Caused By Shield Construction

Since the21st century, the global economy high-speed development, drive thedevelopment of urbanization. Unprecedented tension of the world’s population surge,which leads to the resources, the city ground traffic under pressure, with the progress ofscience and technology, mankind has gradually learn how to make full use ofunderground space. The emergence of the subway, alleviate the ground transportationpressure, the safe, rapid, comfortable, also get the general public to accept. Whether acity developed today, whether can often from the subway traffic measurement.Based on the emergence of the subway, convenience and fast to give human life,how to ensure the safety, construction should be a priority. The present domesticresearch metro tunnel construction in soft soil and clay, etc, have accumulated morestuff, but relatively few of northwest loess geological research, this paper focuses onshield and research development in the loess area, and applications.In the western city of metro shield construction project as the platform, with thebasic theory of shield construction, combining with character of collapsibility loess,through numerical modeling and field measurement method, such as study ofcollapsible loess deformation and subsidence area of shield construction on formation ofrelevant laws; Analysis of the loess property on the formation and the influence ofexcavation surface near the building settlement; Estimate stratum deformation using thePeck formula, analysis and study of strata subsidence monitoring data, the existingthrough linear regression and least squares method to find the Peck formula stratum soilloss rate and settlement trough width variation range, and carries on the appropriatecorrection, can make a better prediction in loess area of shield tunneling on formationdeformation and settlement rule.Through the establishment of FLAC3D numerical simulation prediction of shieldtunnel causes deformation of the stratum structures related law, through comparativeanalysis of calculation results, it is concluded that adopting what kind of reinforcementmeasures can better control the ground subsidence and deformation; Through numericalsimulation analysis of the nature of loess, loess internal friction Angle and cohesion ofthe influence of stratum subsidence and deformation. Scheme design of stratasubsidence and building foundation deformation monitoring, field test and in-situ test results will be compared with the calculated results, observe the tunnel constructioninfluence scope layer settlement on the mainland of the numerical simulation value andthe measured values change trend, the detection accuracy of FLAC3D numericalsimulation results, FLAC3D numerical calculation is used to predict the feasibility ofstrata subsidence.