| 摘要: |
| 覆盖层砂卵砾石地基是一种典型的坝基条件,材料的力学特性关乎坝基的应力变形特征,影响大坝变形协调安全与控制。本文研究覆盖层地基砂砾石材料的力学特性,在此基础上提出适用于该类材料的本构模型。统计分析了覆盖层对于坝体变形的影响规律,阐明了研究的必要性。以淤泥含量作为影响因素,开展了不同围压条件下覆盖层砂砾石材料固结排水三轴剪切试验,分析了淤泥含量对材料应力应变和体变特性的影响。根据试验结果,评估了邓肯张模型对该类材料的适用性,针对邓肯张模型的不足,提出了一种改进的可以表征覆盖层砂砾石材料应变软化和剪胀特征的本构模型。量化了模型参数的确定方法,构建了淤泥含量和模型参数之间的回归关系。最后采用本文和已有研究中室内试验结果对模型的性能进行了评价。本研究对覆盖层地基上大坝的变形准确估计和协调控制提供了前提条件。 |
| 关键词: 覆盖层砂砾石 三轴试验 淤泥含量 本构模型 应力应变 |
| DOI： |
| 分类号:TV41 |
| 基金项目:国家自然科学基金(52479132；52125904)；陕西省教育厅科研项目(23JP113) |
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| Study On Mechanical Properties and Constitutive Model of Sand-Gravel with Mud in River Alluvium |
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CAO Weifeng1,2,3,2,4, WEN Lifeng1,2,3,2,4, YANG Ying5,2,4, SI Zheng1,2,3,2,4
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1.State Key Laboratory of Water Engineering Ecology and Environment in Arid Area,Xi'2.'3.an University of Technology,Xi'4.an;5.PowerChina Northwest Engineering Corporation Limited,Xi'
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| Abstract: |
| Alluvium sand-gravel (SG) foundation is a typical dam foundation condition. The mechanical properties of the alluvium material are related to the stress and deformation characteristics of the dam foundation, and affect the coordinated safety and control of dam deformation. This paper investigates the mechanical properties of SG material in alluvium foundation, and further proposes a constitutive model suitable for this type of material. The influence of the alluvium foundation on the dam deformation are statistically analyzed, and the necessity of the study was clarified. Based on the statistical results, silt content is taken as an influencing factor. Taking mud content as an influencing factor, the consolidation and drainage triaxial shear tests of alluvium SG materials under different confining pressure conditions are carried out to analyze the influence of mud content on the material stress-strain and volume deformation characteristics. According to the test results, the applicability of the Duncan-Chang |
| Key words: Alluvium sand-gravel Triaxial test Silt content Constitutive model Stress-strain |
