Numerical Investigation on Time-Dependent Deformation in Roadway

Yuantian Sun,Deyu Qian,Guichen Li,Bicheng Yao,Junfei Zhang,Jiandong Huang,Fan Gu

doi:10.1155/2021/4280139

Abstract

The roadway deformation normally relates to time especially for underground coal roadway. The strength of soft coal is low, and therefore the deformation increases gradually under constant stress with time, which is called rheology deformation. In this study, based on a field case, the rock mass properties and deformation data of the roadway were obtained according to the field test. A 3D numerical model was then established, and the rheological deformation including horizontal and vertical deformation of the coal roadway was systematically analyzed. The results showed that the rheological deformation of horizontal sidewall accounts for almost 30% of the whole deformation, and the stable time for such roadway is around 60 days after excavation. The tendency of the roof deformation is similar to the sidewalls, and however, the floor deformation is different. Then the related suggestions for maintaining the stability of such roadway were proposed, which is useful in-field application.

Highlights

Driving tunnels in deep conditions especially in the underground coal mine is a challenge [1]. ere are a lot of roadways with soft coal mass in coal mines in China, which normally occurs with large deformation and failure [2]
Parts of the roadways are in soft geological conditions such as coal roadway and weak rock mass, and the deformation exhibited time-dependent behaviors [3,4,5]
To maintain the stability of such roadway, a series of approaches have been proposed such as high-stress support, grouting reinforcement, and a combination support system

Summary

Introduction

Driving tunnels in deep conditions especially in the underground coal mine is a challenge [1]. ere are a lot of roadways with soft coal mass in coal mines in China, which normally occurs with large deformation and failure [2]. There is some commercial software such as FLAC, FLAC3D, UDEC, and 3DEC, which are used in geotechnical engineering or underground engineering [11,12,13,14]. By these programs, the stability of the roadway in underground conditions can be simulated and calculated quickly, meaning the decision can be made soon based on numerical results. To improve the efficiency and accuracy of numerical modeling, some combined methods have been proposed such as FLAC+UDEC and FLAC3D+RS [15]. The rock mass properties affect the deformation obviously, and accurate input parameters can improve the accuracy significantly

Results

Discussion

Conclusion