Abstract In view of the characteristics of upper-soft and lower-hard rocks with poor self-stability in the contact zone between red clay and sandstone interbedded with mudstone, this paper, by carrying out field investigation and analysis, clarifies the construction principles and optimizes the construction methods and support parameters through the numerical simulation calculation in combination with actual conditions on the site. The field application results show that the position of the lithological interface has an obvious effect on the deformation and structural stress of the tunnel when construction in the contact zone of red clay and sandstone with mudstone, as the proportion of red clay in the excavation section increases, the displacement around the tunnel and the initial support stress increase significantly; after optimizing the construction method by adjusting the height of benches and cancelling the reserved core soil, the maximum deformation value does not exceed the allowable value, the maximum compressive stress of the initial support does not reach the material failure strength, and the stress concentration phenomenon of surrounding rocks is weakened, meeting the safe construction requirements; the advance rate is significantly increased, avoiding the problems such as rock falling and collapsing in the lithological interface.
Abstract：
In view of the characteristics of upper-soft and lower-hard rocks with poor self-stability in the contact zone between red clay and sandstone interbedded with mudstone, this paper, by carrying out field investigation and analysis, clarifies the construction principles and optimizes the construction methods and support parameters through the numerical simulation calculation in combination with actual conditions on the site. The field application results show that the position of the lithological interface has an obvious effect on the deformation and structural stress of the tunnel when construction in the contact zone of red clay and sandstone with mudstone, as the proportion of red clay in the excavation section increases, the displacement around the tunnel and the initial support stress increase significantly; after optimizing the construction method by adjusting the height of benches and cancelling the reserved core soil, the maximum deformation value does not exceed the allowable value, the maximum compressive stress of the initial support does not reach the material failure strength, and the stress concentration phenomenon of surrounding rocks is weakened, meeting the safe construction requirements; the advance rate is significantly increased, avoiding the problems such as rock falling and collapsing in the lithological interface.
YU Jie
.Study on Reasonable Construction Method for Tunnels in Contact Zone of Red Clay and Sandstone Interbedded with Mudstone[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(2): 174-181
2021, Vol. 58 