激振法对软岩高地应力超前释放数值模拟研究

Numerical simulation of high geostress relief in soft rock by the mechanical vibration method

针对高地应力软岩隧道的应力释放现状的缺点与不足,提出了一种新的超前应力释放方法,采用激振器进行机械激振的方式来对岩体进行预处理,完成应力的超期释放,从而有利于减小隧道后续开挖完成后衬砌的变形。并且针对隧道掘进机(tunnel boring machine,TBM)掘进技术,参考现有的井巷共振掘进技术,采用一种适配于TBM掘进系统的新设备,根据新设备的工艺以及作用方式,对激振过程进行了模拟分析,并且针对激振频率、激振幅值以及激振深度三个因素与应力释放的相关性进行了研究,得到了最有利于应力释放的频率、幅值与深度,并结合模拟后续隧道开挖所得到的隧道变形结果,进一步验证了此种工况组合的有效性,为该方法的后续实际应用提供了依据。

In view of the shortcomings and insufficiency of current stress release methods for the tunnel in soft rock with high geostress,a new advanced stress release method was put forward,where the mechanical vibration exciter was used to pretreat the rock mass,in order to release the stress in advance,which was beneficial to reduce the deformation of the lining after the follow-up tunnel excavation would have been completed.In view of the tunnel boring machine(TBM)driving technology,referring to the existing shaft and roadway resonant driving technology,and adopting a new equipment suitable for the TBM driving system,according to the corresponding technology for the new equipment and mode of action,the process of excitation was simulated and analyzed.The correlation of the frequency,amplitude and depth of excitation with the stress release was studied.The frequency,amplitude and depth which were most favorable for stress release were obtained,and the validity of this combination was further verified by the tunnel deformation records obtained in the following tunnel excavation.The results provide a reference basis for the subsequent practical application of the method.