单桩及二桩承台水平承载性能试验研究

Experimental Study of Horizontal Bearing Behavior of Single Piles and Pile Cap with Two Piles

为研究承台对桩基水平承载性能的影响,以都江堰市金马河鲤鱼沱大桥为背景,分别对2根单桩及二桩承台进行水平静载试验。水平静载试验在开挖好的坑槽内进行,采用慢速维持加卸载法。对单桩及二桩承台的水平临界荷载、水平极限荷载进行测试,分析单桩与承台下桩身随深度的水平变形及影响深度。试验结果表明:承台能够显著地提高桩基的水平承载力,增强其抵抗水平变形的能力;与S1、S2单桩相比,二桩承台水平临界荷载分别增加了264%和191%,水平极限荷载分别增加了238%和195%。

To study the influences of the pile cap on the horizontal bearing behavior of pile foundation,the Liyutuo Bridge over Jinma River in Dujiangyan City was cited as an example and the horizontal static load tests were respectively made for the two nos.of the single piles and the pile cap with two piles.The tests were carried out in an excavated pit,using the slow maintaining loading and unloading method.The horizontal critical loads and horizontal ultimate loads for the single piles and the pile cap with two piles were measured and the displacement deformation values and influential depth of the single piles and the pile shafts under the pile cap changing with the depth were analyzed.The results of the tests demonstrate that the pile cap can significantly improve the horizontal bearing capacity of the pile foundation and increase the capacity of the foundation against the horizontal deformation.As compared to the single piles S1 and S2,the horizontal critical load of the pile cap with two piles is increased by 264％ against the pile S1 and 191％ against the pile S2 while the horizontal ultimate load is increased by 238％ against the pile S1 and 195％ against the pile S2.