<p>Clarifying the stress and deformation characteristics of stratified rock under dynamic and static loads is crucial for ensuring the safe construction of tunnel by drill and blast excavation. Taking the deep-buried diversion tunnel in Peru as a case study, this paper carried out the similar proportion tests and static deformation model tests on tunnel stratified rock to analyze the deformation behavior of rock mass at different positions of tunnel section. In addition, the effects of static load, dynamic load, and rock inclination on the stress distribution and deformation characteristics of stratified rock are analyzed by LS-DYNA. A predictive model for stratified rock, covering both peak stress and secondary equilibrium stress, was established via dimensional analysis. Limiting dynamic and static loads for safety control of stratified rock with different rock inclination is obtained. The main conclusions are as follows: Within the static load range of 0.2 to 0.8&#xa0;MPa, the stress and strain of rock basically show a linear relationship. As the stress continues to increase, the structural stability of stratified rock at the left spandrel and left hance may fail first. The impact of dynamic load on the rock structural stability is significant. After the cessation of dynamic loading, the rock stress re-establishes equilibrium under static loads, resulting in a general increase in the overall stress value. Static and dynamic loads have a greater impact on the stress and deformation of the rock, while rock inclination mainly affects the position of stress concentration and deformation. The sensitivity order of different factors to the peak stress and secondary equilibrium stress of the surrounding rock is: dynamic load &gt; static load &gt; rock inclination. Combined with the stress prediction model and the first strength criterion, the limiting dynamic and static loads for safety control of stratified rock at different rock inclinations is obtained, which can provide safety guidance for on-site construction.</p><p><b>Highlights</b><UnorderedList Mark="Bullet"> <ItemContent> <p>The deformation characteristic of stratified rock under static load were obtained through model test and similar material ratio test.</p> </ItemContent> <ItemContent> <p>The propagation characteristics of stress wave under dynamic and static loads are comprehensively analyzed.</p> </ItemContent> <ItemContent> <p>The effects of static load, dynamic load, and rock inclination on the stress distribution of stratified rock were investigated.</p> </ItemContent> <ItemContent> <p>A stress prediction model is developed, which can obtain the failure types of stratified rock under dynamic load and static load.</p> </ItemContent> </UnorderedList></p>

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Dynamic Response and Safety Control of Stratified Rock in Tunnels Under Dynamic and Static Loads

  • Yumin Yang,
  • Nan Jiang,
  • Yingkang Yao,
  • Chuanbo Zhou,
  • Xianzhong Meng

摘要

Clarifying the stress and deformation characteristics of stratified rock under dynamic and static loads is crucial for ensuring the safe construction of tunnel by drill and blast excavation. Taking the deep-buried diversion tunnel in Peru as a case study, this paper carried out the similar proportion tests and static deformation model tests on tunnel stratified rock to analyze the deformation behavior of rock mass at different positions of tunnel section. In addition, the effects of static load, dynamic load, and rock inclination on the stress distribution and deformation characteristics of stratified rock are analyzed by LS-DYNA. A predictive model for stratified rock, covering both peak stress and secondary equilibrium stress, was established via dimensional analysis. Limiting dynamic and static loads for safety control of stratified rock with different rock inclination is obtained. The main conclusions are as follows: Within the static load range of 0.2 to 0.8 MPa, the stress and strain of rock basically show a linear relationship. As the stress continues to increase, the structural stability of stratified rock at the left spandrel and left hance may fail first. The impact of dynamic load on the rock structural stability is significant. After the cessation of dynamic loading, the rock stress re-establishes equilibrium under static loads, resulting in a general increase in the overall stress value. Static and dynamic loads have a greater impact on the stress and deformation of the rock, while rock inclination mainly affects the position of stress concentration and deformation. The sensitivity order of different factors to the peak stress and secondary equilibrium stress of the surrounding rock is: dynamic load > static load > rock inclination. Combined with the stress prediction model and the first strength criterion, the limiting dynamic and static loads for safety control of stratified rock at different rock inclinations is obtained, which can provide safety guidance for on-site construction.

Highlights

The deformation characteristic of stratified rock under static load were obtained through model test and similar material ratio test.

The propagation characteristics of stress wave under dynamic and static loads are comprehensively analyzed.

The effects of static load, dynamic load, and rock inclination on the stress distribution of stratified rock were investigated.

A stress prediction model is developed, which can obtain the failure types of stratified rock under dynamic load and static load.