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采用冻结法开凿的立井井筒,若干年后发生井壁破坏,是我国近年来多次出现的工程问题。本文综合介绍了主要的破坏情况,进而统计分析了破坏时间、围岩水文条件变化及破坏点位置等方面的规律性,以井壁破坏的显现特征为基础,对其破坏的原因进行了分析,指出:最底部含水层水压头下降而沉降产生负摩擦力是井壁破坏的主因,而温度应力是井壁破坏的诱因。同时对主因和诱因对井壁所产生的应力情况进行了数学分析,给出了若干实测结果和计算公式,提出了今后防止井壁继续破坏的可行途径.
The use of freezing method to mine vertical shaft, shaft wall damage occurred several years later, is our country in recent years many engineering problems. In this paper, the main failure conditions are introduced synthetically. Then the regularity of failure time, hydrological conditions of surrounding rock and the position of failure point are statistically analyzed. Based on the appearance characteristics of borehole damage, the causes of the damage are analyzed. It is pointed out that the negative friction caused by the falling of the hydraulic head in the bottom aquifer is the main cause of borehole wall failure, and the temperature stress is the incentive of borehole wall failure. At the same time, the author analyzes the stress caused by the main cause and inducement to the well wall, gives some measured results and calculation formulas, and puts forward the feasible ways to prevent the wall from continuing to destroy in the future.