围岩支护作用关系中的温度影响因素研究

Research on the Effects of Temperature on the Interaction Between Rockmass and Support

隧道围岩支护作用关系是隧道研究领域的关键问题之一,衬砌混凝土的温度变化会影响隧道围岩与支护的相互作用。当衬砌混凝土的温度升高或降低时,衬砌结构会膨胀或收缩,由于受到围岩的约束会产生围岩温度被动反力。文章通过建立简化的圆形隧道分析模型,得出了围岩温度被动反力随衬砌温度变化的计算公式,分析了影响围岩温度被动反力的因素,并采用既有隧道衬砌置换工程的现场监测数据进行了验证。研究结果表明:围岩温度被动反力是衬砌温度变化量、材料参数和几何参数以及围岩材料参数的函数,可以进行量化计算;在衬砌施作初期,由于水化热的影响,温度被动反力增长较快,峰值达到0.4 MPa左右。随着水化热的消散,温度被动反力逐渐减小。研究成果可为衬砌围岩松动压力现场监测提供一种温度修正方法。

The interaction between rockmass and support is one of the key topics of tunnel research since the temperature change of a concrete lining will affect the interaction between the tunnel rockmass and support： that is to say, the lining structure will expand or shrink when the temperature of the concrete lining increases or decreases due to the passive resistance caused by rockmass confinment. By means of a simplified circular tunnel analysis model, a calculation formula for the passive rock resistance varying with the lining temperature is obtained, the factors affecting the passive rock resistance are analyzed, and the measured data obtained from an existing tunnel lining replacement project are verified. The research results show that： the passive rock resistance under temperature action is a function of the lining temperature variables, lining material parameters, geometrical parameters, and rockmass material parameters, and it is available for quantitative calculation; the passive rock resistance increases rapidly in the primary stage of lining installation because of the hydration heat effect, with a peak value around 0.4MPa, while it decreases gradually with the dissipation of hydration heat. Based on the research results, a temperature correction method is available for monitoring the loosening rock pressure at site.