沉井-桩复合基础水平承载性能模型试验分析  

Experimental Analysis of Horizontal Bearing Performance of Caisson-pile Composite Foundation

作　　者：穆保岗[1] 陈祉阳 龚维明[1] Mu Baogang;Chen Zhiyang;Gong Weiming(School of Civil Engineering,Southeast Uniersily,Nanjing,211189,P.R.China;Nanjing Dongu Consruction Technology Co.,Lud.,Nanjing 211164,P.R.China)

机构地区：[1]东南大学土木工程学院,南京211189 [2]南京东土建设科技有限公司,南京211164

出　　处：《地下空间与工程学报》2022年第1期190-200,共11页Chinese Journal of Underground Space and Engineering

摘　　要：沉井-桩复合基础在桥梁深水工程中具有独特优势,为进一步揭示该基础形式在水平荷载作用下的承载性能,在砂土中进行了各种沉井、桩的水平承载性能模型试验,并与现行规范理论计算结果进行比较。试验结果表明:沉井-桩复合基础的水平承载能力远高于单一沉井和桩基础,其水平荷载位移曲线呈现明显的非线性特征;初期主要依靠沉井侧壁被动土压力和底部的水平摩阻力来抵抗水平力,后期群桩的水平抗力才逐渐发挥,桩最终分担的荷载比例稳定在1/3左右,采用修正的等效单桩法可提供比较准确的计算结果。沉井-桩复合基础的良好水平承载性能为其在复杂环境的工程应用提供了可能。Caisson-pile composite foundation has unique advantages in deep-water bridge engineering. In order to further reveal the bearing capacity of this foundation under horizontal loads, models of various caissons and piles were designed and tested in sand under horizontal load and the results were compared with the current code. Tests results show that the horizontal bearing capacity of the caisson-pile composite foundation is much higher than single caisson or pile, and load-displacement curve reveals nonlinear characteristics. Caisson-pile composite foundation mainly relies on the earth pressure of passive zone of side wall and bottom friction resistance of caisson to resist horizontal load during the initial period. With the load increasing, the role of pile groups begin to play, and the final proportion of sharing load is nearly 1/3 in the test. Modified GEP method can provide more accurate calculation results. The above good performance of caisson-pile composite foundation makes it possible for its applications in complex environments.

关 键 词：沉井-桩 水平承载力 模型试验 复合基础 

分 类 号：TU473.2[建筑科学—结构工程]