深部巷道围岩瞬态温度-热应力的耦合作用

Study on coupled transient temperature-thermal stress in deep roadways

为了研究深部巷道温度场与应力场的耦合作用,采用理论推导得到圆形巷道围岩瞬态热-弹性耦合解析解,分析了巷道围岩温度场和热应力的分布规律,并通过数值模拟和现场观测研究了热应力对巷道围岩稳定性的影响。研究表明:围岩温度分布呈非线性变化,表层温度梯度大,围岩深处温度梯度小;随通风时间延长,围岩温度逐渐降低,冷却圈不断增大,温度梯度逐渐减小,温度分布曲线趋于平缓;通风能够改变围岩应力状态,切向热应力在围岩表层表现为较大的拉应力,而在深处表现为较小的压应力;径向热应力为拉应力,热应力加剧了巷道围岩顶底板塑性区扩展的深度。

This paper is aimed at investigating the coupled rules underlying temperature tletd and stress field of deep roadways. The investigation is performed by deducing the coupled transient thermal-e- lastic analytical solution of surrounding rock of circular roadway, analyzing the distribution rule of temper- ature field and thermal stress of surrounding rock of roadway, and identifying the influence of thermal stress on the stability of rock surrounding roadways by numerical simulations and in situ measurements. The results show that surrounding rocks occur with nonlinear changes in temperature distribution, the large gradient in surface layer , and the smaller gradient in the depth; the increased ventilation time gives a gradual decrease in surrounding rock temperature, an increase in cooling ring, and a decrease in tem- perature gradient, thus tending to leave the temperature distribution curve quite gentle; the roadway ven- tilation allows such a change in the stress state of surrounding rock that the circumferential thermal stress occurs as tensile stress with the larger value in surface layer of surrounding rock and as compressive stress with the lesser value in the depth of surrounding rock of roadways ; and the radial thermal stress, identi- fied as tensile stress ,intensifies the extension depth of the plastic zone in roof and floor of roadways.