高地应力作用下大理岩岩体的TBM掘进试验研究

滚刀破岩效率的研究主要集中在室内线性试验机破岩试验和数值分析2个方面,在工地开展TBM掘进试验尚不普遍。锦屏二级水电站采用3台TBM开挖隧道群,3台TBM在不同洞深(不同地应力)条件对大理岩岩体进行TBM掘进试验、岩石渣片筛分试验及大渣片统计分析,研究岩体条件、TBM机器参数、TBM运行参数对TBM掘进速度的影响及高地应力作用下岩体可掘性指数的变化。研究结果表明:在高地应力条件下,尽管TBM掘进速度随推力增加而增大,但推力超过一定值后,TBM并不在优化状态下运行,TBM的运行需与岩体条件及地应力条件相匹配。

EXPERIMENTAL STUDY OF TBM PENETRATION IN MARBLE ROCK MASS UNDER HIGH GEOSTRESS

The study of rock breaking efficiency by rolling cutters mainly focuses on laboratory linear cutting experiment and numerical simulation analysis. Tunnel boring machine(TBM) penetration test is not popularly conducted in project sites. Three TBMs are used to respectively excavate the headrace tunnel #1，#3 and the construction drainage tunnel in Jinping II hydropower station. The TBM penetration tests，the sieve tests of the rock chips and big chip statistical analysis are carried out respectively in these three tunnels under different tunnel buried depths(namely different geostresses). The influences of engineering-geological conditions，TBM parameters and TBM operation parameters on TBM penetration rate and the variation in rock mass boreability index under high geostress are analyzed. The analysis results show that under high geostress，although the penetration rate of TBM increases with increasing thrust force，TBM does not operate in optimal state while the thrust force is larger than a specific value. TBM operation should match with the conditions of rock mass and geostress.