万家寨引黄工程泥灰岩段隧洞岩石掘进机(TBM)卡机事故工程地质分析和事故处理

隧道全断面岩石掘进机 (TBM )的施工对地质条件适应性是一个不断认识和深化的过程 ,其中很多认识是来自已发生的各种各样事故和对事故原因的理性认识。本文是在对某隧洞TBM卡机地段的岩性 (包括工程性质 )、构造、地应力及其在TBM施工条件下的变化等方面进行工程地质力学研究的基础上 ,指出层间剪切带的存在及由此而产生的较大变形速率是导致事故发生的工程地质原因 ,并提出了相应的处理意见和建议。TBM卡机问题的顺利解决和它重新开始快速掘进证明了作者分析和工程处理措施的合理性。本文的分析有助于加深TBM施工对复杂地质条件适应性的认识 ,并可望为避免类似事故的再次发生提供参考和借鉴。

A CASE STUDY ON TBM BLOCK IN MARLS AT CONNECTION WORKS NO.7 TUNNEL OF YELLOW RIVER DIVERSION PROJECT

This paper presents a case study on an exceptional event of TBM blocking in a section of the Connection Works No.7 tunnel of Yellow River Diversion Project in China. By analysis of lithology, fold, rock mass strength and geo-stress, it indicates that a high rate deformation with respect to inter-layer shear zone in the lower part of the anticlinal core is a dominant factor resulting in TBM blocking. Also the previously encountered unfavorable conditions in forms of wet clay, groundwater inflow, and cavities are coincident with tensile stress in lower part of the syncline. The syncline and anticline make the fold. Based on these diagnoses, economical and quick curing measurements such as enlargement excavation outside of the shield leaving free space to unlock the TBM were adopted. After 9 days blocking, the TBM was totally released and undertaken normal excavation again. Unlike those frequently encountered and discussed unfavorable geological conditions such as jointed, fractured rock mass and faulted zone, this instance mostly highlights a lesson learnt from folding and inter-layer shear zone in TBM tunneling.