固结灌浆前、后引水隧洞衬砌力学行为研究

Mechanical Behaviors of Water Diversion Tunnel Lining before and after Consolidation Grouting

以洞松水电站引水隧洞为工程背景,采用FLAC有限差分软件对固结灌浆前后引水隧洞衬砌的力学行为进行分析。分析认为:固结灌浆可以有效加固岩体,封闭隧洞周边岩体裂隙,改善衬砌受力状态,提高衬砌抵抗变形和破坏的能力。但是,固结灌浆在施作时会对衬砌产生很大的附加荷载,计算显示固结灌浆造成衬砌最大压应力增大了30%左右,导致了衬砌的二次变形。如果固结灌浆施作不当压应力可能更大,甚至会压垮衬砌造成衬砌的严重破坏。通过选取不同的施工工法可以有效减小固结灌浆在施作时对衬砌产生的附加荷载,分段固结灌浆对衬砌产生的附加荷载要小于全孔一次灌浆时对衬砌所产生的附加荷载。

Based on the engineering background and finite element simulation about the diversion tunnel of Dongsong Hy -dropower Station ,the mechanical behavior analyses about the diversion tunnel lining between and after the consolidation grouting are conducted respectively .The results present that the consolidation grouting can reinforce the rock effectively , modify the crack propagation around the tunnel ,improve the stress condition about the lining ,and enhance the anti-de-formation and anti-fracture ability of the lining .However ,the consolidation grouting will cause the significant additional load in the lining ,the simulating results show that the consolidation grouting has caused 30% augment about the maxi-mum stress in the lining ,and in turn caused the secondary deformation ,thus ,the inappropriate consolidation will cause the increasing of compressive stress ,even the possibility of the thorough damage of the lining .Finally ,through different construction meghods ,the additional stress of the lining in consolidation grouting will be decreased effectively ,thus the additional stress in segment consolidation grouting will be smaller than that of full hole grouting at a time .