Abstract TBM tunnels through the high mountain will inevitably encounter high stress problem,and the research on the influence mechanism of high stress on TBM breakage is very important. The influence of confining pressure on rock fragmentation by TBM cutters is successfully studied by using mechanical analysis and numerical simulation,and it implies that the impact of confining pressure is very complicated. The depths of crushed zone and lengths of cracks parallel to normal force decrease with increasing confining pressure,but confining pressure facilitates rock fragmentation and promotes chipping process,and the side cracks will develop rapidly and smoothly. The TBM in-situ penetration experiment shows that the rock is excavated more easily by TBM with increasing confining pressure. Considering the difficulty of rock chipping by TBM cutters,the results of mechanical analysis and numerical simulation and TBM in-situ penetration experiment all prove that confining pressure is favorable to TBM cutter breakage and penetration.
|
Received: 27 May 2013
|
|
|
|