锦屏二级深埋隧洞构造型岩爆诱发机制与案例解析

INDUCEMENT MECHANISM AND CASE ANALYSIS OF TECTONIC ROCKBURST IN JINPING II DEEP BURIED TUNNEL

全长超过16 km的锦屏二级深埋隧洞沿线经过不同的地质单元。在开挖过程中,岩爆的诱发受控于地质构造条件以及由其所导致的局部地应力场,其中与地质构造直接关联的构造型岩爆影响最为突出。系统总结国内外深部工程中岩爆研究的前沿成果,结合锦屏二级水电站深埋隧洞工程中大量岩爆案例所揭示的客观规律,将构造型岩爆进一步细分为端部构造型、滑移构造型和应变构造型岩爆。采用离散元程序和相关的岩爆风险评价指标,开展深入地岩爆案例反演和机制解译,揭示深埋隧洞工程不同类型构造型岩爆的发生机制,并分析该类工程环境下关键岩爆控制因素及各因素的控制机制。最后,针对不同类型的构造型岩爆,提出相应的防治方案,可以为类似工程提供借鉴。

The total length of Jinping II deep buried tunnel cross different geological units is more than 16 km. In the process of excavation,rockburst was controlled by the geological structure conditions and the local stress field. The tectonic rockburst is directly affected by the geological tectonics. Based on the systematic analysis of the forefront research results about rockburst in deep engineering home and abroad,and combined with the rockburst revealed by a large number of cases in Jinping II deep buried tunnel engineering,the tectonic rockbursts were further subdivided into end tectonic,slip tectonic and strain tectonic. The inverse analysis of the rockburst was carried out with the discrete element program and related risk evaluation index of rockburst. The mechanism of different kinds of tectonic rockburst in deep buried tunnel engineering was revealed,and the key controlling factors of rockburst and control mechanisms of various factors were analyzed. Finally,the corresponding control schemes were put forward according to the different types of tectonic rockburst.