针对高地应力赋存环境下深埋隧洞连续爆破开挖过程,采用ANSYS/LS-DYNA动力有限元软件模拟分析了围岩应力演化规律。通过对比分析准静态地应力重分布、地应力重分布与爆破荷载耦合作用2种工况,获得了高地应力赋存环境下深埋隧洞连续爆破开挖推进过程中的围岩应力演化规律及影响因素:深埋隧洞围岩主要表现为高地应力作用下的剪切破坏,隧洞连续爆破开挖卸荷过程中地应力重分布是洞壁远区围岩应力场改变的主要原因,炸药爆炸产生的爆破荷载只对炮孔附近的围岩应力产生影响,使炮孔附近围岩产生爆破张拉损坏。就本算例而言,连续爆破开挖卸荷只对掌子面后方约4 m范围内围岩产生影响,连续2个循环进尺后隧洞围岩应力场基本趋于稳定。
Abstract
The stress evolution law of surrounding rock during continuous blasting excavation in deep underground tunnel with high geostress is studied by ANSYS/LS-DYNA dynamic finite element software model. By comparing and analyzing the results of two working conditions, namely quasi-static stress redistribution, and ground stress redistribution coupled with blasting load, the evolution law and influential factors of stress evolution of surrounding rock under continuous blasting are obtained.Shear failure is the main failure pattern. The redistribution of stress is the main reason for the change of stress field in the surrounding area of the tunnel; blasting load only affects the surrounding rock stress in the adjacent of explosive holes by inducing damage. In the research case of this paper, continuous excavation unloading only affects the surrounding rock in the range of about four meters behind the working face, and after two successive footages, the stress field of surrounding rock of the tunnel is basically stable.
关键词
深埋隧洞 /
爆破开挖 /
地应力重分布 /
数值模拟 /
高地应力
Key words
deep-buried tunnel /
blasting excavation /
in-situ stress redistribution /
numerical simulation /
high geostress
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基金
国家自然科学基金项目(51509126,U1765207);江西省自然科学基金项目(20181BAB206047);南昌大学研究生创新专项资金项目(cx2016098)
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