基于堆填厚度及填筑速率的拓宽路基变形研究

在软土路堤结合工程中,软土的长期变形效应不仅影响道路的使用寿命,而且将使新老路堤间出现不均匀变形,因此对施工过程中路基变形及工后沉降控制是路基拓宽工程中急需解决的工程难题。本文将以南京滨江大道拓宽工程为研究对象,研究内容如下：针对南京浦口滨江大道K11＋500断面,建立有限元模型,研究在不同堆填厚度与不同的填筑速率的条件下不对称拓宽路基的变形机制。结果表明：填筑速率越快,工后沉降越大,工后差异沉降也越大,孔隙水压力不易消散,影响土壤固结,要及时打设排水板,加快工程进度。随着填土层厚的增加,相同填筑速率下的填土差异沉降量也在变大。

Research on widen subgrade in the condition of different dumping thickness and filling velocity

The deformation of roadbed and control of post-construction settlement are both great challenges in widen subgrade projects because of the long-term deformation effect of soft soil. The stability and deformation of the case in the condition of different dumping thickness and filling velocity was discussed, based on the FEM model for soft soil subgrade of new building Pukou highway. The result shows that the post-construction settlement and the differential subsidence of pavement increased with the increasing filling velocity. In this situation, pore water pressure is not easy to dissipate,so the soil consolidation rate decreases. To accelerate project schedule, drainage board should be built up in time. And the differential subsidence of pavement under the same filling velocity is increasing when the dumping thickness increases.