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自80年代以来,中国东部黄淮地区许多生产矿井的立井井筒相继出现了程度不同的破裂,对煤矿的安全生产造成威胁.在详细调查的基础上,本文首先归纳了该地区井筒破裂的特征,主要有:(1)井筒破裂段大多位于上覆表土层与基岩交界面附近上下数米之内;(2)井筒破裂时间基本集中在1987年之后的短短几年内,与矿井投产时间长短无对应关系;(3)破裂过程一般是内井壁先出现裂缝,后掉混凝土块,渐渐露出已弯曲的钢筋,最后出现环形带状破裂;(4)井内设备变形明显滞后于井壁破裂.本文介绍了近年来我国学者有关井筒成片破裂机理的研究情况,以及对破裂段采取的加固方法及效果.根据其中一个井筒破裂最为严重的煤矿进行的井下原地应力测量结果,考虑当地地质资料,进行了地应力场有限元模型分析.结合区内地震活动、新构造运动的若干表现以及地壳应力、形变观测对井筒破裂的原因进行了综合分析,认为新构造运动引起的水平构造应力增高可能是黄淮地区井筒成片破裂的主要因素,区内特殊的底含结构及采动引起的四含水流失可能是井筒出现破裂的诱发因素.
Since the 1980s, shaft fractures of shaft in many production mines in Huanghuai area of east China have successively appeared different degrees of rupture, threatening the safety of coal mines.On the basis of detailed investigation, this paper first summarizes the characteristics of borehole rupture in this area, Mainly include: (1) Most of the wellbore rupture sections are located within a few meters above and below the interface of the overlying topsoil and bedrock; (2) The wellbore rupture time is basically concentrated within a few years after 1987, No corresponding relationship; (3) the rupture process is generally the first borehole wall cracks, concrete block after, gradually exposed bent steel, and finally ring-shaped rupture; (4) Well deformation in the well was behind the wellbore rupture. In this paper, we introduce the research status of the wellbore cracking in our country in recent years, as well as the reinforcement methods and effects on the rupture.According to the result of in-situ stress measurement in one of the coal mines with the most ruptured wellbore and the local geological data , The finite element model analysis of the geostress field was carried out.Combined with the seismic activity in the area, some new tectonic movements and the crustal stress and deformation observation It is concluded that the increase of horizontal tectonic stress caused by neotectonic movement may be the main factor of the failure of the wellbore in Huanghuai area. The special bottom substructure and the four water loss caused by mining may be the wellbore Cracking induced factors.