Optimization Analysis of Shallow Tunnel Excavation

Abstract

In this paper, FLAC3D, the general software for geotechnical engineering project, is used to conduct two-dimensional numerical simulation for typical shallow tunnel excavation methods which include full-section method, the upper and lower step method, three-step method and CRD method etc.Effects of different excavation methods to the stability of tunnel surrounding rock are analyzed. The paper selected a subsistent tunnel as the research object. With construction simulation of different excavation methods, the paper makes comparative analysis of laws and characteristics of displacement of tunnel surrounding rock , stress distribution and size of plastic zones under different excavation methods. Study shows that: Ι.Followed by two step method, CRD engineering method and the full-section method successively, the three-step method is the best in the aspect of control of surrounding rock stress,; ΙΙ. Followed by full-section method, two- step method and the three step method successively, CRD engineering method is the best,in the aspect of size of plastic zones; Ш. Followed by three-step method, two-step method and the full-section method, CRD construction is the best in the aspect of control of surrounding rock displacement.

Analysis of the influence of tunnel portal section construction on slope stability

“…Up to now, many research workers who major in the tunnel project bring a large number of mathematical analysis methods into the analysis of the stability of the slope such as block limit equilibrium method imbalance thrust method, Principle of red flat projection analysis (Jin, Cui, & Lu, 2000;Xiao, 2001;Yang & Cheng, 2002). Along with the development of computer technology, the researchers also bring the simulation research into the field (Tang, Wang, & Li, 2011;Zhang, Lou, Huang, Liu, & Yang, 2011;Zhao, Shao, & Hang, 2009). A preliminary study of the engineering stability of the Shilou tunnel in the Hipparion red clay were studied by the establishing of finite element numerical model (Peng, Ma, Wang, & Xie, 2013;Wang, Gao, Quan, & Qin, 2014;Wang & Wang, 2009;Wang, Xia, & Gu, 2013;Xie & Wang, 2004).…”

Study of the stability of tunnel construction based on double-heading advance construction method

“…Vardakos et al 11 used Universal Distinct Element Code (UDEC) software to carry out numerical analysis for Shimizu large-section tunnel in Japan, verifying the mechanical construction effect of ''TBM heading excavation method,'' and they studied the law of surface subsidence at the same time. By the step method, full section method, and CRD method in the excavation of soft rock tunnel, Zhao et al 12 adopted FLAC3D to simulate the stress of the surrounding rock in the process of construction, and the results showed that the excavation based on CRD method had a good controlling effect on the displacement of surrounding rock. With the engineering background of Chongqing Rail Transit Line No.…”