浙江省大梁山隧道出口边坡稳定性分析

研究表明,大多数工程岩体失稳以结构面的剪切破坏为主,因此结构面的抗剪强度就成为影响工程岩体稳定性的决定性因素。通常结构面抗剪强度参数的获取可通过直剪试验及经验估算获得,但在岩石工程稳定性的分析、计算中所用的结构面抗剪强度参数的获取基本上都通过直剪试验获得。经验估算方法同直剪试验相比,有费用低、考虑工程岩体的实际工程条件及尺寸效应等优点,用其估算结构面抗剪强度参数具有较大经济价值及工程意义。在野外结构面定向统计测量基础上,用结构面抗剪强度经验估算方法获得其抗剪强度参数,再利用详细的工程地质资料、赤平投影定性分析及确定工程岩体的破坏模式,选用与破坏模式相匹配的数学力学模型,定量计算分析工程岩体的稳定性。理论分析及工程实践表明,该边坡总体上是稳定的,但楔形体处容易失稳,须处理。

Stability analysis of the slope at exit Daliangshan tunnel in Zhejiang Province

Study shows that most of engineering rock mass destabilizations are resulted from shear strength destruction of joints.So joint shear strength become decisive factor to rock mass stabilities.Generally,shear strength parameters of joint can be obtained by direct shear test and empirical methods.But among the methods of analysis and calculation of engineering rock mass stability,direct test is almost the only way to obtain joint shear strength parameters.Actually,empirical methods,compared with direct test,have a lot of advantages,such as low cost,considering joint scale effect and surrounding conditions of engineering rock mass,therefore,it is of great economic value and engineering significance to use empirical method to estimate joint shear strength parameters.Based on survey of rock joints in the field,shear strength parameters of joints are estimated by using an empirical method,and according to detailed engineering geological data.stereographic projection is also used to analyze and determine failure modes of rock mass.Mathematic-mechanical models which conform to failure modes are chosed,and the stability of rock mass are quantitatively calculated and evaluated.Theoretical analysis and engineering practice shows that the slope is generally stable,but wedge-shaped blocks is easily going to destabilize,it must be reinforced.