Safety Research On Lining Structures Of Subway Station And The Existing Tunnel Underlying

With the development of transport facilities, there has been a large number of light-rail and subway's construction. The trend of building a new line (such as subway, light rail, etc.)near the existing lines is certainly can not be stopped, and there will be increasing the size, the distance will be getting closer. This will inevitably result in the construction of new structures will change the existing structure of the original force, and thus produce a variety of its adverse effects, such as the lining of the structure of capacity declined, and even the destruction of surrounding rock deformation and excessive intrusion of the existing structures sphere of influence and so on. In this paper, Yuzhong District Daping rail transit station on the 1st line construction project for the background, by the use of large-scale finite element analysis software ANSYS simulated Daping subway station on the two construction methods of two-dimensional and three-dimensional numerical simulation. From the sinkage of the surface, the displacement, the stress of new subway station and tunnel operated underlying, as well as the distribution of plastic zone and so on ,evaluated the safety of the new and existing structural's lining, and come to a construction method that makes the minimum influence to the safety of existing tunnels. Finally, compared and analyze the results of monitor measuring and mumercal simulation, to prove the correctness of the numerical simulation and the construction on-site programs and make recommendations to guide the reference.In this paper, and the results are as follows:â‘ From the analysis of the special relationship of the new subway station of Daping 1st line and the existing light-rail tunnel on the 2nd line,made research on the design parameters of the tunnel and carried out on the 1st paragraph of the stations'support parameters and surrounding rocks'calculated parameters, and describes the monitoring projects and measurement methods relevant.â‘¡In accordance with tunnl lining - rock mechanics of the different concepts ,made a discussion about making the complexity of spatial relationships between the new subway station and the underlying tunnel to simplify into two plane problems. According to the principle of simplification, take the load from digging a new subway station on the existing tunnel lining, this separate analysis is theâ… simplified method; take the digging new subway station with the existing analysis of the combined effect of the tunnel, namely,â…¡simplified method. Secondly, by simulating the new station after the lining of the expansion of the foot arch, through the analysis of the lining of existing tunnel to discuss that whether the larger arch foot subway station is beneficial to the force condition of the existing tunnel's lining, and whether made the improvement of the existing tunnel lining forced. In addition, through simulation analysis of entire-section method and two side-wall pilot method construction subway station, preliminaryly obtained the best construction method.â‘¢Using the three-dimensional numerical simulation of the excavation of the new subway stations of different construction methods. From the compared analyze the new station and existing tunnel's dome sinage and Horizontal convergence, the internal force of supporting structure, surface sinkage, the distribution of plastic zones of surrounding rocks in progress of excavation, in order to obtain the recommendation of the new subway station construction method. Make comparison between the results of three-dimensional numerical simulation, two-dimensional numerical simulation and the results of monitoring measured , which provided the basis for optimizing the design and practical experience and the actual construction of the theoretical study.