摘要
大型交通、矿山和水利工程TBM施工中不可避免会遇到复合地层,复合地层中TBM双滚刀破岩特征与均质岩层有较大差异。基于数值流形方法处理非连续问题的能力,引入弱不连续物理覆盖来对复合地层层理面进行表征,提出了模拟裂隙网络扩展过程的数值流形算法,进一步建立了模拟复合地层滚刀破岩过程的数值流形模型。同时,对软硬不均复合地层中不同刀间距的双滚刀破岩过程进行了模拟分析,研究发现:在相同贯入度下,不同滚刀间距的应力分布均具有明显的不对称性,硬岩中滚刀推力远高于软岩,从而易造成滚刀偏磨;当滚刀间距为100 mm时,两滚刀间岩片厚度达到最大值23.7 mm,刀间距增大或减小时,岩片厚度均出现降低趋势;不同刀间距条件下,软岩的破碎率均高于硬岩,其中软岩破碎率随刀间距的增加而增大,硬岩破碎率则在刀间距为100 mm时达到最大值10.5%。上述结果表明,在复合地层中,岩性对于TBM岩机安全及破岩效果的影响要大于滚刀间距,研究成果可以反映复合地层滚刀破岩规律。
TBM tunnels in large traffic engineering,mining and hydraulic engineering will inevitably encounter the mixed face ground. The rock fragmentation characteristics under double cutters in mixed ground are different with the homogeneous ground. With the consideration of the capacity of numerical manifold method to handle the discontinuous problems,a new concept called weak-discontinuous physical covers was introduced to describe the interface of mixed ground and a fracture network propagation numerical manifold method was proposed. Furthermore,the model of numerical manifold was presented for simulating rock fragmentation process under double cutters in mixed face ground. A series of simulations with different cutter spacing demonstrated that: The stress distribution is obviously asymmetry under the same penetration depth in any cutter spacing. The cutter thrust in hard rock is higher than that in soft rock,which is easy to cause eccentric wear; The rock slice thickness reaches the maximum value when cutter spacing is 100 mm,and the thickness will decrease when cutter spacing change; In any cutter spacing conditions,the percentage of frag-mentation in soft rock is higher than that in hard rock. Especially,the percentage of fragmentation in soft rock increases with the increase of the cutter spacing,while the percentage of fragmentation in hard rock reaches maximum value10. 5% when cutter spacing is 100 mm. The results show that the influence of rock property on the rock fragmentation is higher than cutter spacing. The research conclusions can reflect rock fragmentation law under the TBM cutter in mixed face ground.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2015年第6期1225-1234,共10页
Journal of China Coal Society
基金
国家重点基础研究发展计划(973)资助项目(2014CB046904)
国家自然科学基金重点资助项目(41130742)
