已建索柱网架结构稳定索变更加固方法

稳定索是索柱网架结构抵抗向上风作用和保持结构稳定的常设构件,且都施加预应力。若变更已建索柱网架结构稳定索的形状,必然引起网架结构内力较大变化,导致内力超限杆件较多。此时替换超限杆件施工难度极大,而拆除重建,其成本又太高。因此,需要一个合理的稳定索变更加固方法。文章利用ANSYS有限元程序,对某已建索柱网架结构稳定索变更后的受力性能进行了计算分析。结果表明,通过合理设计稳定索与网架的连接方式和施加的预应力,可使原索柱网架结构所有杆件在稳定索变更后依然满足其受力要求,从而大大地降低了其加固的难度、工作量和成本,可为类似工程问题加固提供参考。

Composite active control system of roof and side truss cable for large section coal roadway in fold coal pillar area

In order to solve the surrounding rock control problem of large section gangue replacement roadway under complicated conditions, this paper analyzed the impact to the roadway controlling produced by the geological conditions such as high ground stress, folded structure tilted roof asymmetry and soft wall rock, and built the tilt layered roof structural mechanics model to clarify the increase span mechanism of the weak coal instability. Then, we proposed the combined control system including roof inclined truss cable, coal-side cable-channel steel and intensive bolt support. And then by building the structural mechanics model of roof inclined truss cable system, the support principle was described. Besides, according to this model, we deduced the calculation formula of cable anchoring force and its tensile stress. Finally surrounding rock control technology of large section roadway in fold coal pillar area was formed. Field practice shows that the greatest roof convergence of gangue replacement roadway is 158 mm and coal-side deformation is 243 mm. Roadway deformation is controlled effectively and technical support is provided for replacement mining.