对于深埋、软弱矿山巷道,可缩性金属支架是常用的支护形式,以适应围岩发生较大变形及其压力。针对封闭式可缩性金属支架,考虑在较大荷载作用下或围岩产生较大变形情况下支架节产生缩动时,进行其内力的计算。实际上,地下结构为超静定结构,支架缩动为非可逆过程,且缩动后支架形状会产生变化、卡缆将限制支架变形,这些都将使支架产生残余内力。通过计算支架的缩动残余内力、卡缆作用残余内力和荷载作用内力,并相叠加,进而获得支架缩动后支架的真实内力,从而为可缩性支架的设计计算提供依据。
Yieldable steel supports are common support forms in deep and weak roadways of a mine,to accommodate the large deformation of their surrounding rocks.The internal forces of a close type yieldable steel support are calculated,in which the support nodes are yielded in the cases of the great loads or large deformation of the surrounding rocks of a roadway.Actually,the underground structure is a hyperstatical structure.The yielding of the support is an irreversible process.And the shape of the support would be changed and the deformation of support would be limited by the ataples of the support nodes after yielding.So,they would produce the internal force in the yieldable steel support.The true internal force of the support after yielding could be got by calculating the residual internal forces due to the yielding of support and the staple's limited and by adding the internal force due to loads.The results provide a theoretical basis for the design and calculation of yieldable steel supports.