陈柯竹, 李天斌, 马春驰, 等. 2020.基于CDEM的隧道卸压爆破及岩爆抑制效应模拟[J].工程地质学报, 28(3): 667-676. doi: 10.13544/j.cnki.jeg.2019-281.
    引用本文: 陈柯竹, 李天斌, 马春驰, 等. 2020.基于CDEM的隧道卸压爆破及岩爆抑制效应模拟[J].工程地质学报, 28(3): 667-676. doi: 10.13544/j.cnki.jeg.2019-281.
    Chen Kezhu, Li Tianbin, Ma Chunchi, et al. 2020. Simulation of tunnel pressure relief blasting and rockburst suppression based on CDEM[J]. Journal of Engineering Geology, 28(3): 667-676. doi: 10.13544/j.cnki.jeg.2019-281.
    Citation: Chen Kezhu, Li Tianbin, Ma Chunchi, et al. 2020. Simulation of tunnel pressure relief blasting and rockburst suppression based on CDEM[J]. Journal of Engineering Geology, 28(3): 667-676. doi: 10.13544/j.cnki.jeg.2019-281.

    基于CDEM的隧道卸压爆破及岩爆抑制效应模拟

    SIMULATION OF TUNNEL PRESSURE RELIEF BLASTING AND ROCKBURST SUPPRESSION BASED ON CDEM

    • 摘要: 硬岩隧道开挖过程中的岩爆灾害与隧道围岩的应力状态密切相关,卸压爆破可减缓围岩体应力集中程度,是一种直接有效的岩爆防治措施。以巴陕高速公路米仓山隧道岩爆段卸压爆破为例,运用GDEM-BlockDyna(块体动力学仿真系统)软件进行考虑高地应力和岩体非均质性条件的隧道分步开挖数值模拟分析;将卸压爆破作为唯一变量,进行了两组方案(是否进行卸压爆破)的数值模拟对比分析,并结合微震监测数据,对隧道围岩卸压爆破效果进行检验。结果表明:在隧道围岩分步开挖过程(未进行卸压爆破)的模拟中,围岩出现起裂损伤,应力集中和局部裂纹贯通等现象,并可能诱发岩爆灾害;在围岩卸压爆破条件下,围岩应力集中以及损伤程度有所降低,岩爆风险得到抑制。对比两组模拟结果,损伤均集中于拱顶及拱底,损伤半径比值(卸压/未卸压)分别为3.4倍(拱顶)、1.47倍(拱底),损伤体积比值(卸压/未卸压)为5.36倍,但区域最大损伤量值从1(未卸压)降低到0.6(卸压),且围岩应力峰值降低约5 MPa,应力梯度降低0.8 MPa ·m-1,表明围岩仍具有自稳能力,岩爆发生风险降低。相关结果可为隧道高地应力围岩段实施卸压爆破和合理设计卸压爆破方式提供理论依据。

       

      Abstract: Rockburst disasters during excavation of hard rock tunnels are closely related to the stress state of tunnel surrounding rock. Pressure relief blasting can reduce the stress concentration of surrounding rock mass,which is a direct and effective rockburst prevention and control measure. This paper takes the pressure relief blasting of the rock burst section of the Mountain Mi-Cang Tunnel of Bashan Expressway as an example and carries out the numerical simulation analysis of tunnel step-by-step excavation considering high geostress and rock heterogeneity conditions using GDEM-BlockDyna software. It then takes the pressure relief blasting as the only variable and carries out the numerical simulation comparison analysis of two sets of schemes(whether or not pressure relief blasting is carried out). It uses the microseismic monitoring data and tests the effect of pressure relief blasting on the surrounding rock of the tunnel. Under the condition of surrounding rock pressure relief blasting,the stress concentration of the surrounding rock and the degree of damage are reduced,and the rockburst risk is suppressed. Comparing the two sets of simulation results,the damage is concentrated on the vault and the arch bottom. The damage radius ratio(pressure relief/non-pressure relief) is 3.4 times at vault and 1.47 times at arch bottom. The damage volume ratio(pressure relief/non-pressure relief) is 5.36 times. But the maximum damage value of the area is reduced from 1((no pressure relief) to 0.6 pressure relief). The peak stress of the surrounding rock is reduced by about 5 MPa. The stress gradient is reduced by 0.8 MPa/m. These results indicate that the surrounding rock is still self-stability and the risk of rockburst is reduced. The relevant results can provide a theoretical basis for the implementation of pressure relief blasting and reasonable design of pressure relief blasting in the surrounding rock section of tunnel high ground stress.

       

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