加芯水泥土搅拌桩竖向承载特性及单桩极限承载力预测  

Vertical Bearing Behavior of Concrete-cored DCM Pile and Prediction of Ultimate Bearing Capacity of Single Pile

作　　者：刘维 徐光黎 彭文喜[3] 周革 刘府生[3] 宋鑫宇[2] LIU Wei;XU Guang-li;PENG Wen-xi;ZHOU Ge;LIU Fu-sheng;SONG Xin-yu(Institute of Geological Survey,China University of Geosciences(Wuhan),Wuhan 430074,China;Engineering Faculty,China University of Geosciences(Wuhan),Wuhan 430074,China;China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China)

机构地区：[1]中国地质大学(武汉)地质调查研究院,武汉430074 [2]中国地质大学(武汉)工程学院,武汉430074 [3]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《科学技术与工程》2020年第19期7838-7844,共7页Science Technology and Engineering

基　　金：国家自然科学基金(41772314)。

摘　　要：加芯水泥土搅拌桩具有承载力高、造价低、施工便捷等特点。为其工程设计、施工及检测提供有效的科学理论依据,推进其发展应用,利用现场载荷试验、MIDAS数值模拟研究其单桩竖向承载特性,讨论了不同芯长比、含芯率、弹性模量内芯桩对其竖向承载特性的影响,并基于Weibull模型对其极限承载力进行了预测。结果表明:①承载力随芯长比增大而增大最后趋稳定,综合分析得最佳芯长比约为0.722;②总体上含芯率越大其承载力越大最终趋稳定,综合分析得最佳含芯率约0.204;③内芯桩弹性模量对其承载力影响很小,即内芯桩采用C15或C20混凝土就能满足要求;④基于Weibull模型预测加芯水泥土搅拌桩极限承载力整体效果较好,证明了其科学性和高效性,能够给工程实际提供有效参考。Concrete-cored DCM pile has the characteristics of high bearing capacity, low cost and convenient construction. To provide valid scientific theoretical basis for engineering design, construction and testing of concrete-cored DCM pile, and promote its development and application, the field load tests and MIDAS numerical simulation were used to study the vertical bearing behavior of its single-pile. The effects of core length ratio, core ratio, and core piles with different elastic model on their vertical bearing behavior were discussed, and the ultimate bearing capacity of concrete-cored DCM pile was predicted based on the Weibull model. The results show that the bearing capacity increases with the growth of the core length ratio and finally tends to stable. Comprehensive analysis shows that the optimal core length ratio is about 0.722. In general, the larger the core content, the higher the bearing capacity is. And it tends to be stable finally. Fully considered results illustrate that the optimal core content is about 0.204. The elastic modulus of the inner core pile has little influence on its bearing capacity, that is to say, the inner core pile can meet the requirements with C15 or C20 concrete. Based on Weibull model, the whole effect of predicting the ultimate bearing capacity of Concrete-cored DCM pile is great, which proves its scientificity and correctness. It can provide some reference for the engineering practice.

关 键 词：加芯水泥土搅拌桩 竖向承载特性 数值模拟 Weibull模型 承载力 

分 类 号：TU473[建筑科学—结构工程]