大面积堆载下桥梁基桩负摩阻力试验研究  

Field Test on Negative Skin Friction of Bridge Pile Foundation Under Large Scale Vertical Surcharge Loads

作　　者：陈雪奖 周卫滨 邓会元[2] 戴国亮[2] 龚维明[2] 

机构地区：[1]台州市沿海高速公路工程建设指挥部,浙江台州318000 [2]东南大学土木工程学院,江苏南京210096

出　　处：《公路工程》2016年第6期82-88,共7页Highway Engineering

基　　金：国家自然科学基金项目(51478109);国家"973"计划(2013CB036304);浙江省交通运输厅科研计划项目(2014H10)

摘　　要：沿海地区主要通过吹填淤泥及泥沙进行围垦,由于吹填区域土质较差,淤泥软弱土层较厚,在后期填土作用下,土体会产生很大的固结沉降,易对桥梁基础产生较大的负摩阻力,降低基桩承载力,增加桥梁的沉降位移。结合台州湾大桥工程建设,选取三根基桩进行大面积堆载下桥梁基桩负摩阻力试验,研究沿海吹填区域后期填土对桥梁基桩负摩阻力的影响,并结合不同理论方法计算值进行对比分析。现场实测结果表明,堆载高度达到4 m高度,堆载面积为24 m×16 m时,负摩阻力总和达到2 687 k N左右,中性点深度约为29.5 m,约为0.36倍桩长;负摩阻力的发展是随时间而变化的,规范法计算出的负摩阻力总和计算结果比实测结果偏大,在实际工程中应充分考虑负摩阻力的影响。The soil of coastal reclamation produce great consolidation settlement under the area is much poor, and the silt is very thick. The soil will effect of late filling soil, which makes bridge pile foundation produce negative skin friction easily. It will increase the load of bridge pile foundation, and reduce the bearing capacity and increase the settlement of pile foundation. Combined with the Taizhou Bay Bridge Project Construction, the field test are studied towards the effect of coastal reclamation area late filling to negative skin friction resistance of pile foundation of bridge, and there are three piles designed to test. In addition, it combines with different theoretical calculation methods to analysis negative skin friction. According to the field test,when the load height is up to 4 meter and the surcharge load scale is 24 m × 16 re,the total negative skin friction is almost up to 2 687 kN,and the depth of neutral point is about 29.5 meter, nearly being 0.36 times the pile length. Besides, the development of negative skin friction changes over time. The result of domestic norm analysis is larger than field test result. The negative friction should be taken fully into consideration in actual engineering.

关 键 词：桥梁基桩 大面积堆载 固结 负摩阻力 理论计算 

分 类 号：TU473[建筑科学—结构工程]