自平衡试桩法在中风化白云岩桩基承载性能中的应用  

Study on the Application of Self-balancing Test Pile Method in Bearing Capacity of Moderately Weathered Dolomite Pile Foundation

作　　者：肖丽娜 黄质宏[1] 屈文涛 穆锐 蔡行 庞旭峰 XIAO Lina;HUANG Zhihong;QU Wentao;MU Rui;CAI Hang;PANG Xufeng(College of Civil Engineering,Guizhou University,Guiyang 550025,China;Fuzhou University,School of Civil Engineering,Fuzhou 350003,China;School of Civil Engineering,Tianjin Chengjian University,Tianjin 300384,China)

机构地区：[1]贵州大学土木工程学院,贵州贵阳550025 [2]福州大学土木工程学院,福建福州350003 [3]天津城建大学土木工程学院,天津300384

出　　处：《人民珠江》2019年第12期51-55,共5页Pearl River

基　　金：贵州省科学技术基金(黔科合J字[2015]2037号)

摘　　要：采用自平衡试验法对工程中的3根试桩进行试验,以研究中风化白云岩岩基桩单桩承载力特征值、桩身轴力、极限侧阻力和基桩极限端阻力等承载特性,并根据等效Q-s曲线确定了桩基的极限抗压承载力特征值。得出结论:①实测Q-s曲线为缓变型曲线;②桩身上部的轴力呈线性分布,下部的轴力随荷载增加变化明显;③对于试验点以外各基础(桩基)底部的基岩,若其岩质、岩性、破碎程度及风化程度与本试桩处基岩相同,且桩基成孔施工工艺(机械旋挖成孔工艺)一致,才可采用相应的岩石极限端阻力和极限侧阻力,为类似工程提供参考依据。Through self-balancing test method,this paper tests three test piles in the project,to study the bearing capacity characteristics of moderately weathered dolomite pile foundation,including axial force of the pile body,ultimate shaft resistance and ultimate tip resistance of the pile,and determine the ultimate compressive bearing capacity of the pile foundation according to the equivalent Q-s curve.The results show that:①The measured Q-s curve is a slowly changing curve;②the axial force on the pile body is linearly distributed,and the axial force on the lower part changes significantly with the increase of the load;③for the bedrock at the bottom of the foundation(pile foundation)other than the test points,when its type,lithological characters,degree of fracture and degree of weathering are the same as the bedrock at the test pile,and their boring technology(mechanical and rotary drilling technology)for pile foundation is consistent,the corresponding ultimate tip and shaft resistance of rock can serve as reference for similar projects.

关 键 词：自平衡 单桩承载力特征值 桩身轴力 极限侧阻力 基桩极限端阻力 

分 类 号：TU473.1[建筑科学—结构工程]