公路隧道围岩岩体力学本构特征数值分析

Numerical Analysis of Constitutive Property for Tunnel Wall Rock Masses

文章对诸永高速公路某隧道围岩岩体,开展了数值力学试验,在确定连续微元尺寸δ_c,并获取该围岩岩体的各项基本力学参数的基础上,进一步描述了该围岩岩体的力学本构特征。试验结果显示,当δ<4.6m时,各试体应力应变关系曲线变化幅度较大,其弹性阶段、峰值强度,及蠕变形式等均呈明显的不同;当δ≥4.6m时,则应力应变关系曲线开始趋于稳定,其峰值强度、蠕变规律等也基本相似。

This paper carried on the numerical experiment of wall rock masses from the tunnel of Zhu - Yong Highway. Based on determining the continuous micro - element dimension δc and the mechanical parameters, this paper discussed its constitutive property mostly. It was shown by numerical experiment that when δ 〈 4.6m, the stress - strain relationship curve of the respective rock test masses changed radically with size increase. Its elasticity phase, uniaxial strength and creep form and so on varied with the test sampleg dimensions. When δ≥4.6m, the stress - strain relationship curve of the respective rock test masses became stable and changed only a little in some areas. Its uniaxial strength and creep rule and so on were almost the same as the result of others.