人工岛沉降的离心机模型试验与数值分析

Centrifuge modeling and numerical analysis of the settlement of an artificial island

采用离心机模型试验与数值方法,对某一人工岛深厚软黏土地基的沉降特性进行了研究。在模拟现场施工条件下,通过离心机模型试验,研究了60 m厚软黏土地基的沉降特性。基于离心机模型试验,建立了二维有限元模型,应用弹黏塑性本构模型对软黏土地基的沉降规律进行了分析。通过模型试验与数值计算结果的对比分析,结果表明,模型试验与数值计算得到的工后沉降曲线基本吻合,初期沉降速率较大,后期沉降速率相对稳定。在浅部土层,计算得到的超孔压消散快于模型试验结果,而深部土层两者超孔压消散规律基本一致。二者规律的一致性验证了所用数值方法的可靠性。

This paper studies the settlement behaviors of a deep soft clay subgrade in an artificial island. The centrifugal tests are performed to simulate the settlement of foundation soils with a thickness of 60 m. Based on the tests, a 2D finite element model is developed to analyze the settlement behaviors of the foundation soils with implementing an elasto-viscoplasticity constitutive model. Comparisons between centrifugal tests and numerical analysis show that the post-construction settlement curves are in good agreement. The settlement rates are larger in the early stage, but keep stable in the later stage. The dissipation of excess pore water pressure of numerical results is faster than model test for shallow layers; but the tendency from two test has a good agreement in deep layers. The reliability of the numerical method is demonstrated by the consistency between the experimental and numerical results.