Abstract：In order to assess the secondary support time quantitatively,the time-varying self-bearing coefficient of surrounding rock is proposed based upon the Boltzmann rheological model,which aims to investigate the time-dependent process in which the surrounding rock’s self-bearing capacity changes and develops.It takes into consideration the rheological mechanics characteristic of rock based on the self-bearing coefficient of surrounding rock. Then, a new coupling approach between LDP and GRC considering time-dependent effect is established based upon time-varying self-bearing coefficient of surrounding rock, and the secondary support time versus the time-varying self-bearing coefficient of surrounding rock is accurately evaluated.The results show that:1)The change of self-bearing capability of surrounding rock over time is similar at different cross sections of tunnel, namely, self-bearing capacity of surrounding rock drastically reduces in the early excavation stage and then tends to be steadied.And the farther away from the excavation surface,the weaker the self-bearing capacity of surrounding rock is;2)The coupling analysis reveals that the sooner the secondary support is set up,the greater time-varying self-bearing coefficient is.It is not reasonable to carry out the secondary supporting structure when the time-varying self-bearing coefficient drops dramatically over time, because the self-bearing capability of surrounding rock cannot perform well then.
俞缙,马奇飞,涂兵雄,刘士雨,周建烽,蔡燕燕. 围岩时变承载能力定量评估的LDP-GRC耦合新方法[J]. 北京交通大学学报, 2018, 42(4): 9-.
YU Jin, MA Qifei, TU Bingxiong, LIU Shiyu, ZHOU Jianfeng, CAI Yanyan. A new approach of coupling between LDP and GRC for quantitative evaluation of time-dependent self-carrying capacity of surrounding rock. Beijing Jiaotong University, 2018, 42(4): 9-.