Informatics Publishing Limited

Yu Zhang ¹, Yuanxue Liu ¹, Jichang Zhao ¹, Yizhong Tan ², Runze Wu ¹, Zheng Li ¹

Affiliations
1 Chongqing Key Laboratory of Geomechanics & Geoenvironmental Protection, Dept. of Civil Engineering, Logistical Engineering University, Chongqing-401311, CN
2 PLA Engineering College, Xuzhou-221004, CN

Abstract

Underground structures such as the transportation tunnels and people’s air-defense structures are of high importance in the safety of transportation and people’s lives. By now some achievements concerning the static proper arch axis for underground structures have been made, while there has been no research on the dynamic proper arch axis for underground structures under the buried explosion. In this paper, considering the static load and the explosion load, the proper arch axis method for dynamic protection under the buried chemical explosion is proposed. The determination method of the explosion load and the elastic resistance of surrounding rock are established. The dynamic proper arch axis equations for the arch and sidewall as well as the calculation program for the dynamic proper arch axis based on Matlab software are obtained. Numerical calculations using the ANSYS/LS-DYNA platform are used to verify the dynamic protection effects of the dynamic proper arch axis, compared with the static proper arch axis and the conventional arch axis. Results show that adopting the dynamic proper arch axis can improve the dynamic mechanical performance of the structure, and embodies a better explosion protection effect.

Keywords

Underground Structures, Buried Explosion, Protection Method, Spalling Damage, Arch, Optimization.

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Xiaohua Qin ¹, Dongsheng Liu ², Qianghui Song ³, Runze Wu ¹, Xu Wang ¹

Affiliations
1 Department of Civil Engineering, Logistical Engineering University, Chongqing-401311, CN
2 Chongqing Bureau of Geology and Minerals Exploration, Chongqing-400071, CN
3 Chongqing Key Laboratory of Geomechanics & Geoenvironmental Protection, Chongqing-401311, CN

Abstract

Landslide is a major natural disaster, and large number of landslide disasters show that rainfall infiltration is a main factor to induce instability for unsaturated soil slope. To explore the failure mechanism of soil slope under extreme rainfall, the influence of rainfall infiltration for soil slope’s saturation, pore water pressure and displacement are analyzed based on fluid-structure coupling and theory of unsaturated soil mechanics under different extreme rainfall conditions. The results show that: (1) It has same rainfall discharge and rainfall duration for the four kinds of rainfall patterns, but they have different space-time effect on soil slope’s saturation, pore water pressure and displacement. (2) The rainfall pattern has large impact on slope’s displacement, and gradually increasing rainfall has most effective for slope’s displacement than other rainfall patterns after rainfall last 48 h, followed by first increasing and then decreasing rainfall after the first type, the third is gradually decreasing rainfall, and the least is stability rainfall. (3) Different rainfall patterns have different danger points during rainfall, but it occurs at the time that when rainfall intensity up to the maximum. According to the paper, gradually decreasing rainfall has most impact on slope’s stability at early-term of rainfall, first increasing and then decreasing rainfall has most impact on slope’s stability at medium-term of rainfall, and gradually increasing rainfall has most impact at last-term of rainfall.

Keywords

Soil Slope, Failure Mechanism, Extreme Rainfall, Fluid-Structure Coupling, Stability.

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