软岩隧洞TBM施工中围岩变形预测研究

TBM施工过程中,为防止软岩变形导致卡机事故的发生,需要对围岩变形进行准确的预测。以巴基斯坦N-J水电站为研究对象,通过对围岩变形监测数据的反演分析,得到其蠕变参数,并采用反演得到的蠕变参数对大埋深洞段的围岩变形进行预测。结果表明,TBM在软岩段掘进过程中,围岩除了产生明显的弹塑性变形外还会出现明显的蠕变变形,且蠕变变形在TBM在开挖后的几小时内会迅速增加,增大了TBM卡机风险。建议TBM在软岩段掘进过程中,在保证安全的前提下尽可能快速通过。

Prediction of soft rock tunnel deformation in TBM construction

In TBM construction, in order to avoid jamming accident caused by soft rock deformation, the accurate prediction of tunnel surrounding rock deformation is necessary. Taking N-J Hydropower Station in Pakistan as a case, the creep parameters of soft rock was obtained by inverse analysis of deformation monitoring data, and the creep parameters were used to predict the de-formation of the surrounding rock with large buried depth. The prediction results showed that the evident elastic-plastic deforma-tion and creep deformation occurred in the tunneling process, and the creep deformation increases quickly in a few hours after the TBM excavation, which increases the risk of TBM jamming. Therefore, under the premise of safety, the TBM should tunnel through the soft rock as quickly as possible during the soft rock excavation.