山区鸡爪形地基高填石路堤稳定性分析和加固技术研究

STABILITY ANALYSIS AND REINFORCEMENT TECHNOLOGY RESEARCH OF CHICKEN CLAW TRENCH HIGH ROCKFILL EMBANKMENT IN MOUNTAINOUS AREAS

鸡爪沟地形容易造成上部路基变形失稳、不均匀沉降,尤其在其上部修筑高填石路堤,其稳定性问题更加突出,目前尚无这方面研究成果。依托某山区高速公路建设项目,开展有限元计算,重点分析鸡爪沟高填石路堤的稳定性与不同加固技术应用效果。研究发现:此类路基位移变形大于一般路堤,应加强设计验算并采取相应的施工措施;鸡爪沟地基坡度、路堤宽度、路堤高度等指标改变,将引起路肩、坡脚位移明显变化,并显著改变路堤内部应力分布,而边坡坡率在要求以内变化,对路堤变形与应力影响不大。分析挖台阶法、加筋、注浆、强夯等工程措施的适用性与经济性,考虑经济性选取挖台阶法对高填路堤进行加固处理,计算结果表明此方法确保路堤边坡安全系数满足稳定性要求,建议采用此种方法对路堤进行加固。

It is easy for a chicken claw ditch topography to cause the upper subgrade deformation instability and differential settlement, especially when a high rockfill embankment is built in its upper parts, the stability problem would be more prominent.At present there is no research result in the subject.For this reason, based on a mountain area highway construction project, the numerical calculation was carried out with an emphasis on the stability and different strengthening technical effect of the chicken claw ditch high rockfill embankment.The study found that such subgrade displacement deformation was greater than the general embankment, and the design check should be enhanced and the corresponding construction measures should also be taken.The changes in slope, width and height etc of the embankment would cause obvious change in road shoulder and slope toe, as well the internal stress distribution.Step method, the reinforcement, grouting and dynamic compaction were analyzed, and the step method was selected for high rockfill embankment strengthening.Calculation results showed that the method could ensure embankment slope safety factor to meet the requirements of the stability.Considering economy, it was suggested that this method should be used to reinforce such embankment.