Influence of the Strength of Bedding Plane on the Deformation of the Surrounding Rock of Layered Rock Tunnel
The existence of weak bedding planes often directly determines the stability of tunnel surrounding rock,and the strength of bedding planes in different regions is obviously different.In order to reveal the response law of tunnel surrounding rock deformation to the strength of bedding plane,a numerical model of layered rock tunnel with 0 thickness bedding plane was constructed by using the cohesive element method.Combined with the numerical simulation method of acoustic emission(AE),the influence of bedding plane strength on the deformation of tunnel surrounding rock was analyzed in detail.The following results are obtained.The existence of the bedding plane directly affects the distribution of the secondary stress field.The stress concentration phenomenon occurs at the weak bedding plane,which causes the differential deformation at the upper and lower interfaces of the bedding plane,resulting in the dislo-cation slip trend of the bedding plane.With the increase of the strength of the bedding plane,the deformation discordant phenomenon weakens,and the damage degree and the AE energy of the bedding surface decrease.Meanwhile,the existence of bedding plane in-creases the deformation value of tunnel surrounding rock,and the weaker the strength of bedding plane,the stronger the deformation degree.Therefore,it is necessary to carry out the tunnel surrounding rock support design according to the strength characteristics of bedding planes in different regions,so as to ensure the safe construction and stable operation of the tunnel.
layered rock tunnelcohesive zone modelacoustic emissionstrength of bedding planedifferential deformation
万方数据
维普
