用非连续变形法分析岩锚吊车梁失稳形式及机理

An Analysis of Destabilizing Pattern and Mechanism of Rock-Anchored Crane Beam by DDA

岩锚吊车梁是水电站地下厂房重要建筑物之一,其稳定分析方法一直是一个值得探讨的问题。应用非连续变形方法(DDA)分析岩锚吊车梁在吊车轮压作用下的失稳形式,通过计算分析可知,其失稳形式有3种,即滑动式、转动式和混合式;失稳形式主要与接触面(梁体与围岩之间)的摩擦角φ和粘聚力C有关;并且可以通过对岩锚吊车梁预先施加锚固力的方式改变岩锚吊车梁的失稳形式。岩锚吊车梁失稳的主要原因是受拉锚杆抗拉强度和杆体与砂浆粘结强度不够所造成的,改变失稳形式可增加岩锚吊车梁的安全度。

Rock-anchored crane beam is one of underground house important structures, whose stability method is a question which is worth discussing continuously. DDA is used to analyze the destabilizing pattern of rock-anchored crane beam under the crane wheel pressing action. It is known via the calculation and analysis that there are 3 types of destabilizing patterns, that is, sliding pattern, rotating pattern and mixing pattern of sliding and rotating. Destabilizing pattern is mainly related to the friction angle 9 and cohesion force C of contact surface （between beam body and surrounding rock）. The destabilizing pattern of rock-anchored crane beam can be changed via the pre-applied anchoring force to rock-anchored crane beam. The main reason of rock-anchored crane beam destabilization is caused by the weak tensile strength of anchor rod and the weak cohesion strength of concrete mortar. Accordingly, changing destabilizing pattern can increase the safety of rock-anchored crane beam.