软弱破碎直立岩质边坡渐进性破坏及其锚固效应的模型试验研究

软弱破碎岩质边坡在自然界中广泛存在,且多表现为局部化渐进破坏模式。为进一步了解该类边坡的破坏性状及其锚固效应,以Ⅳ类破碎围岩为参照对象,并将其等效为单一均值地层,随后利用模型试验对有、无锚杆加固情况下直立岩质边坡的破坏特性进行研究。结果表明,软弱破碎岩质边坡的塌方主要是由于坡顶岩体的张拉和坡脚岩体的压剪共同作用的结果,且往往呈渐进性破坏机制;锚杆的锚固效应主要体现在抗剪止裂和抗拉伸两个方面,并且锚杆的加固不仅可以提高边坡岩体在破坏前的竖向承载力,而且还可减小岩体的竖向沉降,并允许岩体边墙有较大的侧向变形。

Model test study on the progressive failure of weak and fractured vertical rock slopes and the effect of anchoring

Weak and fractured rock slopes widely exist in nature,and most of them would assume localized progressive failure mode.In order to further understand the failure behavior and the anchoring effect for such slopes,fractured rock of grade Ⅳ is taken as reference prototype.This type of rock mass is made equivalent to an isotropic continual stratum,and a series of model tests were carried out to investigate the failure mechanism of vertical rock slopes with or without bolt reinforcement.The test results show that the collapse of the slope is the combined results of tension failure at the top and compression-shearing failure at the bottom of the rock mass,and it often undergoes progressive failure.The anchoring effect of bolt is mainly reflected by shear resistance,crack resistance and anti-extension.The blot not only can improve the vertical bearing capacity before failure,but also reduce the vertical settlement and allow greater lateral rock wall deformation.