基于正交试验的软岩隧道围岩稳定性影响因素敏感度分析

Analysis on Sensitivity of Factors Affecting Stability of Surrounding Rock of Soft Rock Tunnel Based on Orthogonal Test

基于某供水专用软岩隧道,采用正交试验法对其围岩稳定性影响因素进行敏感度分析,确定影响拱顶沉降、仰拱隆起和水平位移的主要因素,分析各因素对软岩隧道围岩稳定性的影响。结果表明:提高支护结构混凝土等级和厚度可减小拱顶沉降量,支护施工距离的增加会导致拱顶沉降量、仰拱隆起量逐渐增加,采用全断面法开挖可使拱顶沉降和仰拱隆起最小化;混凝土等级是影响水平位移结果的最显著因素,支护施工距离和开挖方案的影响次之,混凝土厚度是影响水平位移结果的较弱因素。提出优化施工方案,建模分析并通过现场监测进行验证。

Based on a soft rock tunnel for water supply,the orthogonal test method was used to analyze the sensitivity of factors affecting the stability of surrounding rock,and the main factors affecting the arch settlement,invert uplift and horizontal displacement and their effects on the stability of surrounding rock of soft rock tunnel were analyzed.The results show that the arch settlement can be reduced with the increase of concrete grade and thickness of the retaining structure,and the increase of support construction distance will lead to the gradual increase of invert uplift.The excavation of full section method can minimize the arch settlement and invert uplift.Concrete grade is the most significant factor affecting the horizontal displacement results,followed by support construction distance and excavation scheme,and the concrete thickness is a weak factor affecting the horizontal displacement results.The optimized construction scheme is proposed,and the model is analyzed and verified by on-site monotoring.