顺层钻孔施工过程中应力和位移变化规律

Variation Laws of Stress and Displacement During Bedding Drilling Construction

为掌握顺层钻孔施工过程中应力、位移变化规律,建立了FLAC3D数值模型,根据模拟结果和钻孔周围应力分布理论,对整个过程中应力、位移变化规律进行分析,并在平煤集团八矿进行钻孔窥视工业性试验。结果表明:钻孔施工过程中,扰动煤体依次经历原始应力、应力升高直至峰值、应力下降、残余应力4个阶段,同时位移增大速度呈现出由小变大再变小的特征;成孔之后,钻孔径向上依次存在卸压区、应力集中区和原岩应力区,距离钻孔中心越近,煤体的位移量越大,反之越小,且与钻孔中心同等距离处的上部煤体位移比下部大。

In order to study the variation laws of stress and displacement during bedding drilling construction, the FLAG3D numerical model is set up. According to the numerical simulation results and drilling ambient stress distribution theory, the variation law of stress and displacement is analyzed. And the industrial test of drilling peep is constructed in eighth coal mine of Pingdingshan Coal Mine Group. Results shows that during the bedding drilling construction, the coal stress possesses following 4 states in turn of origin, peak, drop, remains, and the increasing speed of displacement turned from small to big and small. After drilling, there are pressure relief ar- ea, stress concentration area and original stress area around drilling. The closer to the drilling centerline, the bigger displacement it is, at the same time, the displacement of upper coal is bigger than the lower one.