深埋岩体隧洞滞后型岩爆特征及其时效变形诱发机理研究

发布时间：2018-06-03 23:36

本文选题：岩爆 + 时效变形　；参考：《大连理工大学》2014年硕士论文

【摘要】：伴随着社会和经济的快速发展,越来越多的地下空间被开发利用,地下工程也逐渐具有了“大、长、深、群”等特点,因此地下工程中遇到了更多的深部岩石力学问题,其中尤以岩爆最为突出。岩爆过程大都具有突发性、猛烈性,而滞后型岩爆往往要在开挖结束后,还要经过一段滞后时间才发生。它可以使人们觉得岩爆危险已不存在,过早进入作业区而遭遇危险,国内外很多地下工程中的岩爆都有滞后现象,已经受到地下工程学者普遍关注,但是至今为止对其形成机理都没形成统一的认识。本文以深埋岩体隧洞围岩的时效变形诱发滞后型岩爆这一关键科学问题为核心,依托锦屏二级水电站引水隧洞微震监测项目,深入研究工程实际中滞后型岩爆的孕育特征,将微震监测技术用于水电站深埋岩体隧洞岩爆预测预警,分析隧洞围岩在蠕变过程中的微破裂前兆及其时空演化规律,探讨滞后型岩爆的监测预警方法；基于损伤力学,利用有限元数值分析方法RFPA2D (Realistic Failure Process Analysis)成功再现了滞后型岩爆的围岩时效变形诱发过程,研究了滞后型岩爆时效变形诱发机理,为深埋岩体隧洞中的滞后型岩爆理论研究、监测预警探索新思路。本文主要研究结果如下： 1.隧洞埋深大、地应力高的地方,岩爆、滞后型岩爆发生频率较高,并且岩爆烈度也相对较高,掌子面附近是岩爆高发地段； 2.地质构造对滞后型岩爆有着控制作用。特别是软硬岩互层的位置和向斜构造核部,是强烈岩爆和滞后型岩爆的高发地段； 3.围岩流变损伤积累,微破裂萌生、发展、贯通,并形成宏观裂纹,是滞后型岩爆的孕育过程,也是岩爆滞后发生的重要原因； 4.大量的微震信息对于岩爆具有明显的时间优先性和空间一致性,这是微震监测技术用于岩体隧洞岩爆监测预警的基础和前提； 5.围压(σ3)越高,岩爆的滞后时间可能越长,但不成比例关系；高围压也会使滞后型岩爆烈度、规模、破坏范围都增大。
[Abstract]:With the rapid development of society and economy, more and more underground space has been developed and utilized, and underground engineering gradually has the characteristics of "big, long, deep, group", so underground engineering has encountered more and more deep rock mechanics problems. Among them, rock burst is the most prominent. Most of the rockburst processes are abrupt and violent, while the delayed rockburst usually takes place after excavation, and then takes a period of lag time. It can make people feel that the danger of rockburst is no longer there, and they are in danger of entering the operation area prematurely. The phenomenon of rockburst in many underground projects at home and abroad is lagging behind, which has been paid more attention to by the scholars of underground engineering. But so far, the formation mechanism has not formed a unified understanding. Based on the key scientific problem of time-dependent deformation induced lag rockburst in the surrounding rock mass of deep buried rock mass tunnel and relying on the project of micro-seismic monitoring for diversion tunnel of Jinping II Hydropower Station, the pregnant characteristics of lagged rockburst in engineering practice are deeply studied in this paper. The microseismic monitoring technique is used to predict rockburst in deep buried rock tunnel of hydropower station. The microrupture precursor and its space-time evolution law of surrounding rock in the creep process of tunnel are analyzed, and the monitoring and warning method of lag rockburst is discussed, based on damage mechanics, By using the finite element numerical analysis method RFPA2D / realistic Failure Process Analysis), the aging deformation induced process of the lagged rockburst is reproduced successfully, and the mechanism of the delayed rockburst deformation is studied, which is the theoretical study of the lagged rockburst in the tunnel of deep buried rock mass. Monitoring and early warning to explore new ideas. The main results of this paper are as follows: 1. Where the buried depth of tunnel is large and the ground stress is high, the frequency of rockburst and lagged rockburst is relatively high, and the intensity of rockburst is relatively high. 2. The geological structure has the control function to the lag type rock burst. Especially, the location of soft and hard rock interbedded and syncline structural core is the high occurrence area of strong rockburst and laggard rockburst. 3. The accumulation of rheological damage, the initiation, development, and formation of macroscopic cracks are the gestation process of lagged rockburst and the important cause of lagged rockburst. 4. A large amount of microseismic information has obvious time priority and spatial consistency for rock burst, which is the basis and premise of microseismic monitoring technology for rock burst monitoring and warning in rock tunnel. 5. The higher the confining pressure (蟽 3) is, the longer the lag time may be, but the larger the ratio is, and the higher the confining pressure is, the greater the intensity, scale and damage range of the lagged rockburst will be.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV554;TV223

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