桩间距和桩帽宽度影响土拱效应的现场试验

为了研究桩间距和桩帽宽度对桩承式加筋路堤土拱效应的影响,在广清高速公路拓宽工程庆丰收费站进行了现场试验,实测了路堤荷载下不同桩间距和桩帽宽度下桩帽及桩间土表面的竖向土压力,据此获得土拱高度与桩帽净距的关系.试验结果表明,桩间土表面竖向应力近似均匀分布.当桩帽净距数值超过1.0m以后,土拱高度随桩帽净距的增加而减小.桩帽-土应力比随路堤荷载的增加而增大,随桩帽宽度和桩间距的增加而减小.桩帽荷载分担比随路堤荷载和桩帽宽度的增加而增大,随桩间距的增加而减小.桩间土荷载分担比随路堤荷载和桩帽宽度的增加而减小,随桩间距的增加而增大.

Field Tests on the Effects of the Spacing of Piles and Width of Pile Caps on the Soil Arching

In order to study the effect of the center-to-center spacing of piles and the width of pile caps on the soil arching in a piled embankment with reinforcements,field tests were performed at the Qing Feng toll station constructed on a geogrid-reinforced and PHC pile-supported embankment in the Guangzhou-Qingyuan highway extension project.The contact pressures acting on the pile caps and the surrounding soil were measured in the conditions of different widths of pile caps and spacings of piles,and the relation between the height of soil arch and the clear spacing of pile caps was obtained.The test results show that the vertical stress in the surrounding soil is distributed uniformly.The height of soil arch decreases with the increasing of the clear spacing of pile caps when the spacing is larger than 1.0 m.The pile cap-soil stress ratio increases with the increasing of the embankment load,while decreases with the increasing of the width of pile caps and the spacing of piles.The load sharing ratio carried by the pile caps increases with the increasing of the embankment load and the width of pile caps,while decreases with the increasing of the spacing of piles.The load sharing ratio carried by the surrounding soil decreases with the increasing of the embankment load and the width of pile caps,while increases with the increasing of the spacing of piles.