深厚表土层井壁温度竖向附加应力分析

Analysis of Shaft Lining Temperature Vertical Stress in Deep Topsoil

深厚表土层竖井井壁破裂是严重危害煤矿生产的地质灾害。温度作用是导致井壁内竖向应力增大而诱发井壁破裂的一种重要因素。为了分析深厚表土层立井井壁因温度作用产生纵向膨胀对井壁受力状态的影响,在分析井壁与土体相互作用的基础上,根据热力学和弹性理论建立了井壁和土体剪切作用的弹塑性模型,推导了井壁温度竖向附加应力的计算公式。进一步分析表明:井壁内温度竖向附加应力随深度呈不断增大的趋势,并在基岩附近达到最大值;温度竖向附加应力随着弹塑性剪切段分界点的深度近似呈线性增加。这些结论有助于加深对深厚表土层井壁破裂机理的认识,并对井壁破裂预防治理具有理论指导作用。

The shaft lining rupture in deep topsoil is a geological disaster,which seriously harm the coal mine production. Temperature action is an important factor that results in the increasing of vertical wellbore stress and induces the fracture of the shaft lining. In order to analyze the temperature effect of longitudinal expansion on shaft lining in deep alluvium,on the basis of analyzing the interaction between shaft lining and soil,the el-plastic shearing model of the soil and soil shearing was built according to thermodynamics and elastic theory,and the calculation formula of temperature vertical additional stress is induced. Further analysis shows that the temperature vertical additional stress in shaft lining increases with depth continuously,and reached the maximum value near the bedrock. The temperature vertical additional stress displays as an approximate linear increase with the depth of el-plastic shear section cut-off point. These findings contributes to deepening the understanding on the mechanism of shaft lining rupture in deep topsoil,and provides the theoretical basis for the prevention and governance of shaft lining fracture accident.