Morh-Coulomb近接交叉隧道围岩塑形叠加区分析

Analysis on Surrounding Rock Plastic Overlay Area of Adjacent and Crossing Tunnel Based on Morh-Coulomb Strength Criterion

为定量确定交叉隧道相邻硐室塑性叠加区域半径,并分析其对交叉隧道围岩稳定性的影响,以工程力学中应用最广的Morh-Coulomb强度准则为依据,经理论推导,得到了在上下隧道小净距影响下的塑性区范围及其相应解析解。并在此基础上对影响近接围岩稳定性的因素进行了探讨。结果表明交叉隧道塑性区叠加半径大小与内聚力、支护抗力、内摩擦角、原岩应力、近接距离等因素相关。通过Morh-Coulomb强度方程计算出的结果与实测数据对照,结果相吻合,表明本文提出的塑性区计算公式能较好地反映出交叉隧道围岩的稳定性情况。

To identify the radius of plastic superposition area of adjacent chamber of cross tunnel and analyze its influence on the stability of surrounding rock of cross tunnel,based on the Morh-Coulomb strength criterion which is most widely used in engineering mechanics,through theoretical derivation,the plastic overlay area scope and corresponding analytical solution under the influence of small clear distance is obtained. On this basis,the influencing factors of the stability of proximity surrounding rock are discussed.The result shows that the superposition radius of the cross tunnel plastic zone is related to the cohesive force,the supporting force,the internal friction angle,the original rock stress,the near distance,etc. Comparing the data calculated by Morh-Coulomb strength equation with real measurement data,they are consistent,which shows that the presented plastic area calculation formula can better reflect the stability of the surrounding rock of the cross tunnel.