Experimental study on mechanical properties under dynamics disturbance condition of marble of Jinping deep tunnel [锦屏隧洞深部大理岩动力扰动力学特性试验研究]

作者：Li S.^*; Xu H.; Yan F.; Huang X.; Zhou J.

来源：Journal of Central South University(Science and Technology), 2021, 52(8): 2669-2676.

DOI：10.11817/j.issn.1672-7207.2021.08.014

• Deep marble
• Dynamic disturbance
• Jinping tunnel
• Loading rate
• Tensile strength

In order to study the mechanical characteristics of tunnel rocks under different load conditions and dynamic disturbances, the dynamic impact fracture experiment on the marble of Jinping tunnel was carried out to explore the dynamic characteristics of the marble and the impact of static load under different pre-loading conditions based on the split Hopkinson pressure bar(SHPB) system coupled with a set of preloaded device. The results show that the maximum stress point often lags behind the maximum strain position during the loading process. Therefore, the dynamic tensile strength obtained by the test system is larger than the actual strength. The dynamic tensile strength of Jinping marble is positively correlated with the impact of loading rate, and the static load is increased by every 1 MPa, the strength is reduced by about 2 MPa. The dynamic compressive strength is less affected by the static load when the loading rate is small. When the loading rate is high relatively, the dynamic compressive strength is the largest under a static load of 10 MPa, 20 MPa is in the middle, and 0 MPa is the smallest. The dynamic tensile strength of marble is affected by static tensile strength, static preload and loading rate, and the fitting analysis model shows that it has a linear relationship with static tensile strength and static preload, and has an exponential function relationship with loading rate.

• 单位
  岩土力学与工程国家重点实验室; 中国科学院大学