摘要
为探究水泥土搅拌桩及水泥土搅拌桩复合地基的承载性能,对青岛某厂区的6根水泥土搅拌桩单桩及2组3桩水泥土搅拌桩复合地基进行竖向抗压静载荷试验,并采用修正双曲线模型预测单桩和复合地基的极限承载力。试验结果表明:6根单桩及2组复合地基均未加载到破坏,其Q-s曲线均为缓变形,桩端持力层为全风化花岗岩的水泥土桩桩顶回弹量较大,弹性工作特征明显;桩端持力层为中砂层的水泥土桩桩身弹性工作特征不显著。经推算水泥土搅拌桩单桩承载力发挥系数为0.88,符合《建筑地基处理技术规范》(JGJ 79—2012)中水泥土桩承载力发挥系数的取值范围。经工程实例验证,修正双曲线函数能够精准预测水泥土单桩和复合地基的极限承载力,对于确定本试验中水泥土单桩和复合地基的极限承载力可信度较高。研究成果可为类似的复合地基的设计、施工与检测提供借鉴和参考。
In order to investigate the bearing behavior of composite foundation of cement-soil mixing pile and cement-soil mixing pile, vertical compression static load test of 6 cement-soil mixing pile single pile and 2 sets of 3 pile cement-soil mixing pile composite foundation in a factory area in Qingdao, and used the modified hyperbolic model to pretest the ultimate bearing capacity of the pile. The test results show that the 6 single piles and the 2 sets of composite foundations were not loaded with damage, which the Q - s curves were all slowly deformed, and the cement piles with fully weathered granite at the pile end had a large amount of spring-back and strong elastic working characteristics;the elastic working characteristics of the test pile body with the pile end bearing layer being the middle sand layer is not obvious. It is estimated that the bearing capacity of the single pile of cement-soil mixing pile is 0.88, which is in line with the value range of the bearing capacity of the cement-soil pile in the technical specification for building foundation treatment (JGJ 79-2012). It is verified by engineering examples that the modified hyperbolic function can accurately predict the ultimate bearing capacity of cement-soil single pile and composite foundation. The reliability of ultimate bearing capacity of cement-soil single pile and composite foundation is higher in this test. The research results can provide reference and reference for the design, construction and testing of similar composite foundations.
作者
闫楠
郑晨
白晓宇
张明义
YAN Nan;ZHENG Chen;BAI Xiao-yu;ZHANG Ming-yi(College of Environmental Science and Engineering,Qingdao University,Qingdao 266071,China;College of Civil Engineering,Qingdao University of Technology,Qingdao 266033,China)
出处
《科学技术与工程》
北大核心
2019年第19期247-253,共7页
Science Technology and Engineering
基金
国家自然科学基金(51809146,51708316,51778312)
山东省重点研发计划项目(2018GSF117008,2017GSF16107)
山东省自然科学基金(ZR2017PEE006,ZR2016EEQ08)
中国博士后科学基金(2018M632641)
山东省高等学校计划项目(J16LG02)
青岛市博士后应用研究项目资助
关键词
水泥土搅拌桩
极限承载力
复合地基
现场试验
修正双曲线
预测
cement-soil mixing pile
ultimate bearing capacity
composite foundation
field test
modified hyperbola
prediction
