基于蠕变试验下的海相黏性土蠕变模型研究

发布时间：2018-12-12 04:33

【摘要】：为研究海相黏性土的蠕变规律,采用三轴流变仪,在变动围压与分级加载下,对某大型人工岛下不同深度处海相黏性土原状样进行了三轴固结排水蠕变试验。基于耦合Adachi-Oka模型与Biot固结理论控制方程的推导,编写了2维有限元计算程序CFEM 2D。由常规试验结果给出不同土层海相黏性土的Adachi-Oka模型参数,采用上述程序对蠕变试验进行了数值模拟,得出Adachi-Oka模型适用于描述该地区海相黏性土的蠕变特性。在验证模型的基础上,采用程序CFEM 2D对该人工岛深厚黏性土地基的长期沉降特性进行了计算。结果表明:在荷载施加初期,人工岛沉降速率较大;100年时,超孔压已基本消散完成,地表沉降量达到了88.5 cm;通过与分层总和法结果的对比可知,二者误差约为2.5%,表明数值计算结果具有一定的精度,从而验证了计算程序的可靠性。
[Abstract]:In order to study the creep law of marine clay soil, triaxial consolidation and drainage creep tests were carried out at different depths under a large artificial island by triaxial rheometer under varying confining pressure and graded loading. Based on the derivation of the governing equations of the coupled Adachi-Oka model and the Biot consolidation theory, a two-dimensional finite element program CFEM 2D is developed. The parameters of Adachi-Oka model of marine clay soils in different soil layers are given from the results of conventional tests. The creep tests are simulated numerically by the program mentioned above. It is concluded that the Adachi-Oka model is suitable for describing the creep characteristics of marine clay soils in this area. On the basis of the verification model, the long-term settlement characteristics of the deep viscous soil foundation of the artificial island are calculated by the program CFEM 2D. The results show that at the initial stage of loading, the settlement rate of artificial islands is larger, and in 100 years, the superpore pressure has basically dissipated, and the surface subsidence has reached 88.5 cm;. By comparing with the results of the stratified summation method, we can see that the error between the two methods is about 2.5, which shows that the numerical results have certain accuracy, thus validating the reliability of the calculation program.
【作者单位】：大连理工大学岩土工程研究所;大连理工大学海岸和近海工程国家重点实验室;同济大学地下建筑与工程系;
【基金】：国家自然科学基金资助项目(51179023)
【分类号】：TU411

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