论文部分内容阅读
为了解围岩流变条件下锚杆应力变化规律,在求出西原模型下圆形巷道的黏弹塑性位移解的基础上,运用“中性点”理论,推导出全长锚固锚杆剪应力与轴应力随时间变化的表达式。据现场围岩位移数据,反推出西元模型中的4个参量值。计算结果表明:中性点的位置与时间无关;当围岩处于减速蠕变时,锚杆的应力增加速率减速趋零;当围岩处于等速蠕变阶段,锚杆的应力增加速率随着时间推移减速趋稳。为验证锚杆在巷道服务年限内是否失效与确定二次支护时间提供一种新的思路。
In order to understand the variation law of rock bolt stress under surrounding rock rheology, on the basis of solving the viscoelasto-plastic displacement solution of circular tunnel under Xiyuan model, using the theory of “neutral point”, the full-length anchor bolt Shear stress and axial stress with time expression. According to the displacement data of the surrounding rock, the four parameters in the model of the Western Yuan Dynasty are deduced. The results show that the location of the neutral point has nothing to do with the time. When the surrounding rock is in decelerating creep, the stress increase rate of the rock bolt decelerates to zero. When the surrounding rock is in the constant creep stage, the stress increase rate of the rock bolt increases with The deceleration slowed down over time. In order to verify whether the service life of bolts in the roadway failure and determine the second support time to provide a new idea.