层状岩体横观各向同性劣化模型研究

A Transversely Isotropic Deterioration Model for Layered Rock Mass

层状岩体呈现出明显的横观各向同性力学特征,为此,将层状岩体视作层间岩石与层面组成的复合材料,分别就层间岩石力学性质建立相应的力学模型,并提出了劣化模型的弹模裂化极限取值统一限定条件。可考虑层状岩体强度及弹性模量在峰后随塑性应变增大而减小的现象,更能准确地模拟层状岩体洞室开挖的力学响应。在乌东德水电站陡倾层状岩体洞室的围岩开挖稳定性分析的应用中,计算结果与现场监测结果吻合,证明该模型适用性。

Layered rock mass shows an obvious transversely isotropic mechanical characteristic.In this paper,a transversely isotropic deterioration model is proposed for layered rock mass.In this model,layered rock mass is regarded as a composite material which is composed of interlayered rocks and bedding planes.Corresponding mechanical models are then established for the interlayered rocks and bedding planes,and a unified limit condition of the deteriorated moduli is applied.As the strength weakening and the Young’s modulus deterioration with the increase of plastic strains in the post-peak phase of layered rock mass are all considered in this model,it can accurately simulate the mechanical response of layered rock mass during excavation.Practical application of the model in the stability analysis of the rock mass around the underground powerhouse in Wudongde Hydropower Project proves its applicability,as the predictions of the model agree well to the field monitoring results.