桩承式路堤中填土高度对土拱效应作用的试验研究

Field Experimental Study of Effect of Filling Height on Soil Arching in Piled Low Embankment

为研究低填路堤下应力分布特点,结合武汉市中北路延长线的实际工程,在路堤填土过程中进行了土压力和沉降观测,研究了填土过程中土压力和沉降的变化特点,分析了填土过程中土拱效应的形成规律.试验结果表明,在填土较低时,土压力的分布不均匀,而填土较高时,路堤中土压力分布比较均匀;而且随着填土高度的增加,桩顶及桩间土都有沉降趋势,并且桩间土沉降明显大于桩顶沉降.三角形布置形式下,土拱分布在三角形桩布置形式的各边上,土拱效应在桩土间是逐渐发挥的,并且在填土高度达到0.5s(s=桩中心距)时,土拱效应开始显著发挥.

Based on column-supported embankments project at extension of the zhongbei Road in Wuhan, through field tests on load of embankment filling, the distribution and change rule of pile-soil stress and the differential settlements of piles and soil are obtained; the formation and development process of soil arching effect in the process of filling is analyzed. The results show that the soil pressure is unevenly distributed when the filling height is lower; while soil pressure is evenly distributed when the filling height is higher. With the increase of filling height, the pile top and the soil between piles present subsidence trend; and the settlement of the soil between piles is significantly greater than the settlement of the pile top. Triangle arrangement form, the soil arching distributes the each side of the triangle; the soil arching effect between pile and soil gradually develops; and when the filling height has reached 0.5s（s is the center distance of pile）, the soil arc- hing effect develops significantly.