Characteristic Of Surface Subsidence And Control Research In Sandy Cobble Stratum Caused By Different Shields Excavation

In urban subway construction, construction of shield tunneling method is widely used. Chengdu cobble ground experience in the construction of Line1, Herrenknecht earth pressure balance shield machine construction effect is better, a little faster construction. In order to explore other types of shield machine to adapt and broaden their thinking, saving the cost of the project buy different products shield machine construction came into being. This article is based on the works of Chengdu Metro Line2Phase2(West extension line) shield method construction from the Chengdu region characteristics, mechanical properties and applicability of existing shield machine, the construction of surface subsidence curve, ideal numerical simulation the surface subsidence explore. The main contents are as follows:(1) On the Chengdu formation shield construction features, difficulty and key issues to sort out;(2) The mechanical properties of the two shield machine are described and evaluation;(3) The problems of the shield machine boring transformation opinion;(4) Based on the measured surface settlement data, subsidence curves and analyzed;(5) Finite difference software for numerical simulation of the tunnel excavation explore the characteristics of surface subsidence.In the course of the study, summary of comparative analysis, put forward the corresponding improvement measures in the case of the achievement of the improvement measures, combined with practical engineering analysis of the effect of the improvement. And statistics of the measured data and the simulated excavation, summed up the characteristics of surface subsidence. Therefore, this study will have a guiding significance for the future of these two shield machine use.