软岩堆石料劣化效应及黏弹塑性本构模型研究

Due to the advantages of protecting the ecological environment and saving the engineering investment, many high rockfill dams with widely distributed weak rocks have been and are being constructed. But weak rockfill particles deterioration affected by the external environmental factors are easy to cause and significant deterioration deformation, which may result in the long-term deformation of high rockfill dam and be not conducive to the safe operation of the high rockfill dam. In this study, the particle strength attenuation characteristics and flow rule of the degradation deformation will be studied through the analysis of weak rockfill deterioration test data. Within the framework of the generalized plasticity theory, a viscoelastoplastic constitutive model which can simulate the deterioration deformation will be established. The long-term deformation observations made on typical prototype rockfill dams with weak rocks will be collected and analyzed so that the proposed model will be verified. The newly proposed model will be incorporated into an existing finite element simulation program and used to investigate the effect of weak rockfill particle deterioration on the long-term deformation characteristics of high rockfill dam. The simulation results will reveal the long-term deformation evolution of high rockfill dam with weak rocks and the appropriate layout scope of weak rock material will be proposed. The research results will a provide theoretical foundation and technical support for predicting the long-term deformation behavior of high rockfill dam with weak rocks, and be of important theoretical significance and possess engineering application values.

为保护生态环境，节省工程投资，越来越多的高堆石坝利用分布广泛的软岩料筑坝。但软岩料受外部环境因素影响易造成颗粒劣化，产生显著的劣化变形，是高堆石坝长期变形的重要组成部分，不利于高堆石坝安全运行。本项目针对软岩料劣化效应及本构模型问题，通过分析劣化试验资料，开展软岩堆石料颗粒强度衰减特性和劣化变形规律研究，建立颗粒劣化模型，并基于广义塑形理论构建可合理反映颗粒劣化效应的黏弹塑性本构模型，结合高堆石坝原型观测资料分析验证本构模型的合理性；开发黏弹塑性有限元计算程序，分析环境因素作用下颗粒劣化效应对高堆石坝长期变形特性的影响，揭示高堆石坝长期变形演化规律，并提出软岩堆石料适宜布置范围。研究成果将为利用软岩料构筑的高堆石坝长期变形预测提供理论依据和技术支撑，具有重要的理论意义和工程应用价值。

软岩料受外部环境因素影响易造成颗粒劣化，产生显著的劣化变形，是高堆石坝长期变形的重要组成部分，不利于高堆石坝长期运行安全。因此，本项目针对软岩料劣化效应及本构模型问题，主要研究内容包括软岩堆石料颗粒劣化效应研究，反映颗粒劣化效应的软岩堆石料黏弹塑性本构模型构建，利用软岩堆石料构筑的高堆石坝长期变形演化规律研究。. 取得的研究成果主要包括：（1）通过分析劣化试验资料，得到了颗粒劣化破碎、轴向变形和体积变形的变化规律，揭示了软岩堆石料劣化变形机制，建立了劣化变形流动准则，基于选定的颗粒强度参量，建立了软岩堆石料颗粒劣化模型；（2）构建了可统一考虑加载与劣化效应的软岩堆石料黏弹塑性本构模型，基于ABAQUS有限元软件开发了软岩堆石料黏弹塑性本构模型的UMAT子程序；（3）基于建立的本构模型分析了高堆石坝长期变形特性，揭示高堆石坝长期变形演化规律，提出了软岩堆石 料布置原则。. 结合本项目的研究，共发表论文5篇，其中SCI收录2篇，已录用论文2篇；培养博士后1名，项目负责人入选第四届中国科协青年人才托举工程。. 本项目的研究成果对定量预测利用软岩料构筑的高堆石坝长期变形具有重要意义，可为软岩堆石坝设计提供理论依据和技术支撑。