饱和含水砂层地下水渗流对隧道围岩加固效果的影响研究

 在分析饱和含水砂层的工程力学、渗流特性及其隧道围岩变形特性基础上，提出含水砂层中地下水流速影响高压旋喷桩加固效果的双介质模型，给出高压旋喷桩加固含水砂层失效的临界水力梯度表达式；提出饱和含水砂层中有效加固地层的双液注浆原理。工程实例表明，在采用化学注浆有效降低地层渗透性后，水泥注浆可有效加固饱和含水砂层，避免注浆失效。此技术在含水砂层隧道围岩注浆加固地层中取得成功，对类似工程有重要的参考价值。

STUDY OF INFLUENCE OF GROUNDWATER SEEPAGE ON REINFORCEMENT EFFECT OF TUNNEL SURROUNDING ROCK IN SATURATED WATER-BEARING SAND LAYER

Based on analyses of engineering mechanics，seepage and deformation characteristics of tunnel surrounding rock，a two-medium model for the influence of seepage velocity in saturated water-bearing sand layer on high-pressure jet grouting pile reinforcement effect is presented；and the formula of critical hydraulic gradient of high-pressure jet grouting pile reinforcement failure is given. The reinforcement mechanism of double liquid compound grouting in saturated water-bearing sand layer is put forward. The engineering examples show that chemical grouting is enough to reinforce saturated water-bearing sand layer and can avoid grouting failure，after using chemical grouting to effectively decrease the strata permeability. This grouting system is successfully applied to the reinforcement of tunnel surrounding rock in water-bearing sand layer；and the results have great referential value to the similar projects.