冻融循环中低应力水平加卸载作用下砂岩物理特性研究

Study on physical characteristics of sandstone under loading and unloading effects of low stress level in freeze-thaw cycle

采用无损检测技术,对冻融过程中预加载损伤和无加载损伤的砂岩岩样进行检测,检测内容包括每次冻结、融化、低温烘干后各个岩样的质量、纵波波速、电阻率及浸润面积。通过试验数据分析得到了在不同冻融循环周期条件下,砂岩在不同上限应力循环加卸载作用下的物理特性变化规律及评价岩样敏感程度的最佳参数,为水利水电相关的岩质工程,如岩质的隧洞口、水工边坡等在冻融循环荷载次序作用下的一些稳定性分析提供了参考,也为相关试验优选测试指标提供了依据。

With the non-destructive detection technique, the mass, longitudinal wave velocity, resistance rate and wet area of all the sandstone samples with pre-loading damage and unloading damage in the freeze-thaw process after every time of freezing, tha- wing and drying under low temperature are measured, and then the changing law of the physical characteristics and the optimal parameters for evaluating the sensitivity of the sandstone sample under the cyclic loading and unloading effects with various upper limits under the conditions of various freezw-thaw cycles are obtained through the analysis on the testing data concerned ; which not only provide some references for the relevant rock engineering construction project, e.g. some stability analyses made on tun- nel portal, slope of hydraulic structure, etc. under the effect of the cyclic freeze-thaw sequence, hut also lay a basis for optimi- zing the testing indexes for the related tests.