Numerical Simulation Research of Construction Method for Shallow Buried Large Section Tunnel

Abstract

The background of this paper is based on Deli tunnel of Xi’an to Chengdu Railway passenger dedicated line. In order to compare and optimize this large section tunnel project under different construction methods, General FEA software ANSYS was utilized to simulate and analyze the stress and deformation in 2-D and 3-D. According to the Deli tunnel engineering case, the preliminary comparison and discussion of mechanical properties and deformation characteristics of the construction of bench cut method and two side-wall pilot tunnel method have been carried out. From this simulation, we made the conclusion for different mechanical properties and deformation characteristics in different construction methods. It shows that the two side-wall pilot tunnel method results in less stress and deformation than the bench cut method. Therefore, it is safer to use the former method. The key step for bench cut method is the upper excavation, and the key step for two side-wall pilot tunnel method is the upper core soil excavation. Monitoring and enhanced support of these key areas is imperative to guarantee the smooth construction.

Numerical studies of floor heave control by the rock bolts reinforcement technology in retained gob-side gateroad

“…The implementation of the proposed scheme requires a more complex technology for floor support. The traditional full resin bolts with a diameter of 32 mm and steel pile with the design, described in the studies [38,39], were proposed. The main recommendations are as follows.…”

“…The Drucker-Prager model was used to simulate the behavior of rock mass and filling wall material. The adequacy of this approach to simulation the behavior of the heterogeneous rock mass and concrete material is shown in previous research [39,40].To simulate the behavior of falled roof in goaf, the deformation modulus 30 MPa, and Poisson's ratio 0.45 were applied [41].…”

Floor Heave Control in Gob-Side Entry Retaining by Pillarless Coal Mining with Anti-Shear Pile Technology

“…To simulate the behavior of rock mass, filling wall material, and gangue in the goaf, the Drucker-Prager model was applied. The capability of the Drucker-Prager model to adequately simulate the behavior of pressure-dependent materials (like rocks) has been shown in previous studies [44][45][46]. The bilinear isotropic hardening model was used to simulate the behavior of the steel arch frame, rock bolt, and steel pile.…”

Numerical Simulation Algorithm Design of Influence on Existing Tunnel by Underpass Construction of New Tunnel

“…Difficulties in the construction of tunnels are always greater than those in other engineering works [10] due to the complex mechanical property of tunnels, stress, and deformation factors. Particularly, the surrounding rocks play a significant role in this regard because the structure is mainly supported by the surrounding rocks in a uniform stress system.…”

“…By studying the double rectangular concealed excavation construction after MJS reinforcement, the settlement deformation, internal force, and cracks of the existing station structure meet the corresponding protection standards, and the rationality and feasibility of the design scheme are verified. Numerical simulation is one of the methods to examine such issues [9,10]. Moreover, numerical simulation is preferred by [5] to ascertain the interaction between the soil and rock, besides the tunnel structure.…”