科科迪大桥桩基承载力现场试验研究  

Field test study on pile bearing capacity of Coco d'Ivoire Bridge

作　　者：龚颜军 孙军 邓会元 戴国亮[4] 卞佳 张翌欣 GONG Yan-jun;SUN Jun;DENG Hui-yuan;DAI Guo-liang;BIAN Jia;ZHANG Yi-xin(Road&Bridge International Co.,Ltd.,Beijing 100027,China;China Road&Bridge Corporation,Beijing 100027,China;CCCC Highway Consultants Co.,Ltd.,Beijing 100088,China;School of Civil Engineering,Southeast University,Nanjing,Jiangsu 210096,China;Guangzhou Metro Design&Research Institute Co.,Ltd.,Guangzhou,Guangdong 510030,China)

机构地区：[1]中交路桥建设有限公司,北京100027 [2]中国路桥工程有限责任公司,北京100027 [3]中交公路规划设计院有限公司,北京100088 [4]东南大学土木工程学院,江苏南京210096 [5]广州地铁设计研究院股份有限公司,广东广州510030

出　　处：《中国港湾建设》2022年第6期25-30,36,共7页China Harbour Engineering

基　　金：国家自然科学基金项目资助(51878160);国家自然科学基金项目资助(51678145)。

摘　　要：针对科科迪大桥工程深厚砂性场地,为了确定旋挖钻和回旋钻不同施工工艺下灌注桩的承载特性,现场选取了1.6 m和2.0 m直径4根64~75 m长灌注桩进行静载试验。现场试验结果表明,回旋钻施工的桩基承载力约为旋挖钻施工的31.6%,且主要对侧摩阻力降低较显著。此外,桩长越长的灌注桩因其成孔时间较长,容易出现桩端厚沉渣现象,使得第1次循环加载时发生的沉降明显大于第2次循环加载的沉降量。因此,在本工程深厚砂性土地层中,旋挖钻施工工艺优于回旋钻,缩短成孔时间有利于保证桩基承载力。In terms of the deep sandy site of the Coco d'Ivoire Bridge project,in order to determine the bearing characteristics of the bored piles under rotary auger construction and rotary drill construction techniques,four bored piles with a diameter of 1.6 m and 2.0 m were selected on site for static load test.The field test results show that the pile bearing capacity constructed by the rotary drill is about 31.6%of that constructed by the rotary auger construction,where the shaft resistance is reduced significantly.In addition,the bored pile with longer pile length is prone to thick sediment at the base of the pile due to its longer hole-forming time.As a result,the settlement during the first cyclic loading is significantly greater than that during the second cyclic loading.Therefore,in the deep and thick sandy soil layer of this project,the construction technology of rotary auger is better than that of rotary drill,and shortening the hole-forming time would be helpful for ensuring the pile bearing capacity.

关 键 词：自平衡静载试验 桩基承载力 灌注桩 施工工艺 

分 类 号：U655.544[交通运输工程—港口、海岸及近海工程]