以沪蓉西高速公路工程中发生变形破坏较多的巴东组红层软岩为研究对象,通过室内三轴压缩试验、现场承压板压缩试验及流变试验对岩体的变形特性进行系统分析。室内三轴试验分别对自然和饱水状态下的岩体进行分析研究,建立考虑结构面闭合变形的红层软岩弹性本构模型,并分析水对岩体变形特征的影响;现场承压板试验分别对泥质含量不同的2处岩体进行压缩试验,分析其变形特性的异同,同时对其中一点在外荷载作用下内部岩体的应力分布以及位移影响范围和深度进行探讨,并对循环荷载作用下岩体的变形特性进行分析;流变试验在3级不同荷载下进行,通过试验结果建立考虑结构面闭合变形的流变本构模型。通过以上一系列分析研究,从整体上把握巴东组红层软岩的变形特性,为深入研究该岩体其他特性打下基础,同时对该类岩体组成边坡,尤其是对反倾边坡的设计具有重要的指导意义,也为预应力锚索在该类岩体边坡中的加固效果研究提供参考。
Taking the red-bed soft rock as investigative subject, which has caused many deformation failures during the West-section of Shanghai-Chengdu construction, the deformation characteristics of red-bed soft rock are analyzed through indoor triaxial test, field load-bearing plate test and rheological test. With the tfiaxial test on natural and saturated red-bed soft rocks, the elastic constitutive equations of red-bed soft rock, considering the closing of structural surface, are established; and the deformation characteristics of water-beaming influence is analyzed. By performing load-bearing plate test, the deformation characteristics of two kinds of red-bed soft rocks with different argillaceous contents are analyzed. Meanwhile, the rock characteristics under cyclic load, and the stress and displacement distribution and the influential range and depth are studied. With the rheological test, the rheological constitutive equation considering the closing of structural surface is also established. Through the tests, the deformation characteristics of red-bed soft rock are further understanded, and it can provide the basis for further research. The results can give some advices to the design of counter-inclined red-bed soft rock slope, and can also offer references to the research on the reinforcement effect of prestressed cables.