基于高围压三轴试验的蛋形弹塑性模型参数分析  

Parameter analysis of the egg-shaped elastoplastic model based on triaxial tests of high confining pressure

作　　者：徐日庆[1] 朱黄鼎 孙华俊 张岗平 吴明明 闫自海 XU Ri-qing;ZHU Huang-ding;SUN Hua-jun;ZHANG Gang-ping;WU Ming-ming;YAN Zi-hai(Department of Architecture and Civil Engineering,Zhejiang University,Hangzhou 310058,Zhejiang,China;Zhejiang Provincial Development and Reform Commission,Hangzhou 310025,Zhejiang,China;Power China Huadong Engineering Co.,Ltd.,Hangzhou 311122,Zhejiang,China)

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058 [2]浙江省发展和改革委员会,浙江杭州310025 [3]中国电建集团华东勘测设计研究院有限公司,浙江杭州311122

出　　处：《地基处理》2023年第1期9-18,54,共11页Journal of Ground Improvement

摘　　要：为了验证蛋形弹塑性模型参数在高围压条件下的稳定性,以蛋形函数为基本框架,以塑性功函数作为硬化参数,采用相关联流动法则,建立并发展了适用于应变硬化土体的弹塑性本构模型。通过一系列淤泥质软土应力路径三轴压缩试验结果的分析,利用双线性法、非线性回归等方法,得到了杭州黏土的蛋形弹塑性模型参数,结果表明该模型参数在高压条件下具有较好的稳定性,显示了蛋形弹塑性模型的优越性。进一步对模型参数进行分析,搜集并计算了14组不同土的蛋形本构参数,研究发现,参数a、d能够共同表征土体黏聚力的情况,参数b能够反映土体的抗剪能力。搜集并分析了8类土体的形状参数α和内摩擦角φ数据。研究发现,对于黏性土而言,形状参数α与内摩擦角φ的正切值近似成正比,比例系数k=1.72。In order to verify the stability of the parameters of the egg-shaped elastoplastic model under high confining pressures, an elastoplastic constitutive model suitable for strain-hardened soil was established. This model was developed using the egg-shaped function as the basic framework and the plastic work function as the hardening parameters. Based on the results of triaxial compression tests with different stress paths of silty soft soil, the parameters of the egg-shaped elastoplastic model of Hangzhou clay were obtained by bilinear method and nonlinear regression. The results show that the model parameters have good stability under high confining pressures, which shows the superiority of the egg-shaped elastoplastic model. In order to further analyze the model parameters, 14 groups of different soils were collected and calculated. It was found that the parameters a and d could jointly represent the cohesion of soil, and the parameter b could reflect the shear strength of soil. The shape parameter α and internal friction angle φ of 8 kinds of soils were collected and analyzed. The results indicated that, the shape parameter α of clay is approximately proportional to the tangent of its internal friction angle φ, and the proportional coefficient k is equal to 1.72.

关 键 词：蛋形强度准则 弹塑性本构 高围压室内三轴试验 杭州黏土 参数分析 回归分析 

分 类 号：TU43[建筑科学—岩土工程]