珊瑚礁砂地基承载力载荷试验初步研究  

Preliminary Study of Load Tests on the Bearing Capacity of Coral Reef Sand Foundations

作　　者：史元祺 卢秀莲 曹振中[1] SHI Yuan-qi;LU Xiu-lian;CAO Zhen-zhong(Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin University of Technology,Guilin 541004,China)

机构地区：[1]桂林理工大学广西岩土力学与工程重点实验室,桂林541004

出　　处：《武汉理工大学学报》2022年第1期50-57,共8页Journal of Wuhan University of Technology

基　　金：国家自然科学基金(51968015)。

摘　　要：采用南海珊瑚礁砂,利用平板载荷试验、SPT、DPT等原位测试评估了珊瑚礁砂地基的承载能力,通过埋设光纤变形测试系统和压力盒,得到珊瑚礁砂地基实际剪切破坏形式及荷载传递规律。结果表明:中密状态的珊瑚礁砂地基p~s曲线呈线性发展趋势,以沉降量达到载荷板直径的1%为控制指标,承载力特征值达到320kPa;以附加应力衰减至地表荷载10%为界限,珊瑚礁砂地基影响深度约为1.5~2.0倍基础直径,相同压力条件下其附加应力扩散范围大于弹性变形的应力分布理论值;加载至最大荷载Pmax=1 120kPa,地基内部未出现典型塑性变形区,破坏形式考虑为局部剪切破坏;含砾量和密实度的增长可较大程度提高吹填珊瑚礁砂地基的承载能力。Using coral reef sand in the South China Sea,the bearing capacity of coral reef sand foundation was evaluated by in-situ tests such as plate load test,SPT and DPT,and the actual shear damage form and load transfer law of coral reef sand foundation was obtained by burying fiber optic deformation test system and pressure cell.The results show that,the p~s curve of the coral reef sand foundation in the medium dense state shows a linear trend,with settlement reaching 1%of the diameter of the load plate as the control index,and the bearing capacity characteristic value reaches 320kPa.With the additional stress decaying to 10%of the surface load as the limit,the depth of influence of coral reef sand foundation is about 1.5~2.0times the diameter of the foundation,and its additional stress diffusion range under the same pressure condition is greater than the elastic deformation of the theoretical value of stress distribution.Loaded to the maximum load Pmax=1 120kPa,the typical plastic deformation zone does not appear inside the foundation,the form of damage is considered to be local shear damage.The growth of gravel content and compactness can improve the bearing capacity of blowfilled coral reef sand foundation to a greater extent.

关 键 词：西沙群岛 珊瑚礁砂 原位测试 地基承载力 

分 类 号：TU441[建筑科学—岩土工程]