兖州矿区立井井壁破裂的原因分析及防治

针对兖州矿区有８ 个生产井筒发生井壁破裂事故的问题，在进行调查、治理和分析近期监测资料的基础上，详细研究了本区井壁破裂的原因，认为由于第四系下组水位的强烈疏降引起砂层压缩所产生的垂向附加应力与井壁自重应力之和大于井壁混凝土的强度是导致井壁破裂的最根本原因，提出了可以用ｅ－ｐ 曲线法、ｐｗ －ｆｎ 法和模糊聚类评判法预测井筒的稳定性，同时提出了井筒破坏的防治措施．

Causes and Preventions of Shaft Wall Fracturing in Yanzhou Mining Area

Aiming at the problem of shaft wall fracturing happened in 8 shafts in Yanzhou mining area, the authors have studied the causes leading to the fracturing,and hold that the main cause is the stress accumulation. When the overall stress of the vertical additional stress resulted from the drawdown of piezometric level and the gravity stress of the shaft wall itself is greater than the strength of the wall concrete, the shaft wall will fracture. The e-p curve and p w- f n methods as well as fuzzy cluster method are used to forecast the stability of shaft wall. And some measures to prevent the wall from fracturing are put forward.