Structural Response of the Metro Tunnel under Local Dynamic Water Environment in Loess Strata

Abstract

The reasons, prevention, and control of loess disaster are of great concern in practice. In recent years, Xi’an city, China, has taken the leadership in large-scale construction of subway lines in the loess strata. To study the structural response of the tunnel in loess region under local hydrodynamic environment, an experimental testing in 1g as well as a numerical simulation were performed, in which the achieved results were verified and were found to be in good agreement. Furthermore, the results showed that when the water outlet point is above the lining, the overall stress of the lining is “peanut shell,” as the water pressure of the outlet point decreases, the tensile stress of the top and bottom of the lining increases, while the compressive stress on both sides decreases; the channel form of the flow to the lining changes with the variation of the position of the water outlet point. It is worth mentioning that in the process of water gushing, the closer to the water source, the greater surface subsidence is, and there is a positive correlation between water pressure and surface subsidence. This study is of significant benchmark for the construction, maintenance, and prevention of tunnel in loess strata under the influence of water environment.

Displacement and Stress Characteristics of Tunnel Foundation in Collapsible Loess Ground Reinforced by Jet Grouting Columns

“…In recent years, geological hazards happened frequently [1][2][3], and with the development of rock engineering [4,5] and civil engineering [6][7][8][9], a substantial number of tunnel projects have been constructed in complex geological areas as western development strategies have been implemented in China [10][11][12][13][14][15][16]. e construction of loess tunnels has become a focus of the tunnel field, and many relevant practical experience and theoretical results have been obtained [17][18][19][20][21][22][23]. However, with the increasing number of loess tunnel projects, a new challenge has arisen.…”

The Deformation Characteristics of Weak Foundation with High Back Siltation in the Immersed Tunnel

“…e results of basilar strain contrast, as shown in Table 6, and the difference percentages were 6.0% and 4.30%, respectively. In conclusion, these two settlement calculations are reliable and rational, providing a simple calculation method for predicting settlement deformation [64][65][66][67][68][69][70].…”

Methane explosion accidents of tunnels in SW China

“…Statistical analyses of the typical methane explosion accidents occurring in various countries were made and information of methane emission should be included in geotechnical baseline report (Hanifi et al 2012;Kang et al 2013;Morsali and Rezaei 2017;Qiao et al 2018aQiao et al , 2018b. According to statistics, more than 100 methane tunnels have been built in China since 2005, and China has gained rich experience in the design, construction and operation management of methane tunnels Zhang et al 2018Zhang et al , 2019aZhang et al , 2019bQiu et al 2018aQiu et al , 2018bQiu et al , 2018c. However, during the construction period, due to careless CONTACT Haobo Fan fanhbjc@chd.edu.cn; Rui Ren renrui@chd.edu.cn In the rock mass containing coal seam, methane explosion accidents occur occasionally during tunnel construction.…”