以和顺矿区陷落柱为例研究陷落柱形成机理

摘要

Heshun mining areas upper coal measures coal bearing strata is mainly composed of weak rock of mudstone,sandstone and coal beds in Taiyuan group and Shanxi group.These rock beds under pressure or tension will turn up plastic deformation.The deformation can result in dense shield under cover Ordovician Fengfeng group limestone,which creates conditions for collapse column formed "vacuum suction erosion"in Heshun mining area. Multi periods tectonic stress effect,makes the development of structural fissure in rock,lower Ordovician middle Fengfeng group (O2f)limestone by tension.Because the limestone itself is brittle,makes the limestone surface come into being tension fissure structure,thus is beneficial to the development of karst.Groundwater is constantly on the Ordovician limestone and the overlying caving rock erosion,mechanical handling,the rock cave expands further,o-verlying strata in a temporary steady state again lose balance and continue to collapse.The action fastly and intermit-tently repeat,makes the collapse column continuously upward develop.%探讨了和顺矿区上部煤系含煤地层主要由太原组和山西组的泥岩、砂岩和煤层等软弱岩层组成，这些岩层受压或者受张力会发生塑性形变，这些形变对下覆的奥陶纪峰峰组灰岩形成致密的屏蔽，为和顺矿区陷落柱形成的“真空吸蚀”创造了条件。多期构造应力的作用，使岩层中构造裂隙发育，下部奥陶系中统峰峰组（O2 f）灰岩受拉张，由于灰岩本身的脆性，使得灰岩面发生张性的裂性构造，从而有利于岩溶的发育。地下水则不断对奥陶灰岩和上覆塌落的岩石进行溶蚀、机械搬运，使岩溶洞进一步扩大，处于暂时稳定状态的上覆岩层再次失去平衡而继续塌落，此种作用迅速而间歇地重复进行，使陷落柱不断向上发展。