摘要
全断面岩石掘进机(TBM)的破岩效率主要受刀盘设计和岩体特征的影响。采用颗粒流方法建立了岩石试件与滚刀的数值模型,对TBM滚刀破岩过程的影响因素进行了分析。研究表明,单刃滚刀交替作用下强度较低的岩石中易形成规则的张拉裂纹而生成较大岩碴;强度较高的岩石中滚刀的侧向挤压促使形成块度较小的片状岩碴;双刃滚刀作用下岩石表面受到强烈挤压后出现较大的拉应力,使岩石更易破碎,且仅在强度较高的岩石中才易形成透镜状岩碴。滚刀破岩过程中存在能耗最小的最佳间距,该最佳间距随着岩石强度的增大而减小。滚刀破岩过程中,结构面对裂纹扩展具有显著的控制性作用,并阻隔损伤向结构面下的岩石中渗透;随着结构面与滚刀侵入方向夹角的减小,结构面将引导裂纹向岩石深部扩展,而当夹角较大时,结构面则会引导裂纹横向扩展,易导致大块岩碴的形成。
The cutterhead and rock mass characteristics affect the excavation efficiency of full face rock tunnel boring machine（TBM） strongly.The numerical models are made by the particle flow code method（PFC2D） to simulate the rock fragmentation under TBM disc cutters.Numerical simulation tests show that some factors influence the rock fragmentation process strongly.In the relative weak rocks,the regular tension cracks and the big mucks form more easily,when the disc cutters penetrate rocks alternately;in hard rocks,the formation of small disc shape mucks depends on the lateral extrusion of cutter rings.Under the double disc cutters,the rocks crush more easily because of the tension stress which comes form strong compression of cutters,and the disc shape mucks only form in very hard rocks.There is optimal cutter spacing for different strength rocks,which increase with rock strength decreases.In the process of rock fragmentation,discontinuities control the propagation process of cracks and obstruct the cracks spread to the underside of discontinuities.The discontinuities will guide the cracks spread deep in rocks,when the angle of cut-in direction and discontinuity decreases.And the discontinuities will guide the cracks spread transversely when the angle increases.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2011年第6期1891-1897,共7页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.50725931
No.50839004
No.50909077)
中国地质大学(武汉)优秀青年教师基金资助项目(No.CUGL090218
No.CUGL090212)
关键词
全断面岩石掘进机(TBM)
滚刀
破岩
颗粒流法
数值模拟
tunnel boring machine（TBM）
cutter
rock fragmentation
particle flow code method
numerical simulation
作者简介
孙金山，男，1980年生，博士，讲师，主要从事岩土与地质工程方面研究。E-mail：sun99001@126．com
