桩板墙支挡结构半填半挖路基不均匀沉降影响因素及其控制标准

Factors Causing Differential Settlements and the Mitigation Measures in the Transition Zone of Cut and Fill Area of a Sheet Pile Supported Embankment

半填半挖路基由于挖方和填方岩(土)物理、力学性质、固结时间不同,密实度存在差异,工后往往会出现明显的不均匀沉降现象。桩板墙支挡结构半填半挖路基不均匀沉降变形主要由地基在填方荷载作用下发生的固结变形、路基填方在自身荷载作用下发生的压缩变形以及公路路基在行车荷载作用下发生的累计塑性变形等三个部分组成。当半填半挖路基间的不均匀沉降达到一定数值时,就会导致路面内的拉应力超过路面的极限抗拉强度,最终导致路面产生龟裂和破坏,影响公路的正常营运。结合绵茂公路桩板墙支挡结构半填半挖路基工程,分析了桩板墙支挡结构半填半挖路基不均匀沉降的影响因素,提出了桩板墙支挡结构半填半挖路基不均匀沉降控制标准。

The differential settlement after the construction is usually observed in the transition zone between the fill and cut ar ea in a sheet pile supported embankment due to the differences in the physical and mechanical properties, consolidation time as well as density among the cut and fill areas. The different settlement in a sheet pile supported embankment is consisted of set- tlement in the consolidation settlement in the fill area, compression deformation under the self--weight and the plastic deforma- tion under the vehicle loading. The tension cracks and failure will occur in the pavement when the large differential settlement is induced and the tension limits of the pavement is exceeded. The normal operation of the roadway will be adversely affected. The factors that affecting the differential settlement in the sheet pile supported embankment in the Mianhe Highway are presen- ted in this paper.