真空堆载预压的流固耦合分析

发布时间：2018-05-06 22:07

本文选题：真空堆载联合预压 + 离心机试验　；参考：《河北工业大学》2015年硕士论文

【摘要】：本文依托邢衡高速现场工程和离心机试验对真空堆载联合预压加固软土路基进行了深入分析。沉降结果表明,离心机沉降先快然后迅速减慢,而现场工程沉降速率则是逐渐减慢。从孔隙水压力和土的有效应力结果来看,随着深度的增大,孔压的值越大,而有效应力值在减小,现场工程的孔压消散值要大于离心机试验,相应的有效应力的增大也超过离心机试验,结果表明现场工程的排水效果要好于离心机试验。运用离散元对离心机试验做流固耦合分析,无论是排水体间距2.6m,还是1.3m的两种情况,渗流场中水的运动的基本方向都是向下的,而位移场中土颗粒的方向也是向下的。两种情况的结果对比表明,间距1.3m情况下的固结效果要好于间距2.6m的情况。通过对离心机间距2.6m情况进行进一步研究,本文推导了现场模型的离散元模型。结果表明,渗流场中水的流动方向基本是水平的,模型左右两边的水分别向左右两边流向排水板。位移场中土颗粒的运动仍然以向下为主,不过受到流体体积力的影响,有一些向左右两边运动的趋势。从沉降来看,表面沉降比其他模拟值更接近于现场工程的实测值,孔隙率的变化也更大。无论是实测值还是模拟值,都证明对粉质粘土层的加固效果是最好的,达到了重点加固软土层的目的。
[Abstract]:Based on Xingheng high speed field engineering and centrifuge test, this paper makes a deep analysis on the consolidation of soft soil roadbed by vacuum surcharge combined preloading. The settlement results show that the settlement of centrifuge is first fast and then rapidly slowed down, and the settlement rate of site engineering is gradually slowed down. From the results of pore water pressure and effective stress of soil, with the increase of depth, the value of pore pressure increases, and the effective stress value decreases. The dissipation value of pore pressure of field engineering is larger than that of centrifuge test. The results show that the drainage effect of field engineering is better than that of centrifuge test. The fluid solid coupling analysis of centrifuge test with discrete element is carried out. In both the case of drainage body spacing of 2.6 m and 1.3 m, the basic direction of water movement in seepage field is downward, and the direction of soil particle is downward in displacement field. The comparison of the results of the two cases shows that the consolidation effect is better at 1.3m distance than in the case of 2.6m spacing. In this paper, the discrete element model of the field model is derived through the further study of the centrifuge spacing of 2.6 m. The results show that the flow direction of water in the seepage field is basically horizontal, and the water on the left and right sides of the model flows to the drainage plate respectively. In the displacement field, the movement of soil particles is still mainly downward, but influenced by the volume force of the fluid, there are some trends of moving to the left and right sides. From the settlement point of view, the surface settlement is closer to the measured value of field engineering than other simulated values, and the change of porosity is greater. Both the measured and simulated values prove that the reinforcement effect of silty clay layer is the best, and the purpose of strengthening soft soil layer is achieved.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU472.33

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