大伙房引水隧洞不良地质洞段围岩变形监测及支护措施分析

文章对采用TBM法施工的超长隧洞中含有断层和破碎带的不良地质洞段围岩进行的收敛变形监测数据进行了非线性回归分析,判断出了支护结构对围岩变形的影响。结果发现,支护初期围岩变形很大,仰供浇筑后围岩变形速率明显减小。因此在TBM施工过程中,对不良地质洞段除了一般的支护措施以外,应及时进行仰拱封闭施工;对不良地质洞段围岩变形进行定量分析,判断支护参数的合理性,为TBM顺利通过后面的不良洞段提供经验教训。本成果对同类工程的施工也有一定的借鉴价值。

Monitoring of rock deformation and support for the section with poor geological conditions in Dahuofang water diversion tunnel

Convergence deformation monitoring of surrounding rocks was carried out on the section with poor geological conditions with faults and fault-rupture zone in the super-long tunnel constructed by TBM,with the monitored data analyzed by non-linear regression to estimate the effect of support on the rock deformations.It was found that the surrounding rock deformed very fast at the beginning of support and the rate of deformation became obviously small after invert was laid.Therefore,during TBM construction,it is better to construct the invert in time besides other routine support measures on the section with poor geological conditions.By performing quantitative analysis for the rock deformations and judging the rationality of support parameters,one can help the TBM successfully pass through the section with poor geological conditions.