膨胀岩土内抗拔桩上拔段极限侧摩阻力参数选取  

Selection and Analysis of Ultimate Lateral Friction Parameters of Uplift Section of Uplift Pile Iin Expansive Rock and Soil

作　　者：赵云川 饶传友 郭钾 ZHAO Yun-chuan;RAO Chuan-you;GUO Jia(Sichuan Electric Power Design Consulting Co.,Ltd,Chengdu 610041,China)

机构地区：[1]四川电力设计咨询有限责任公司,四川成都610041

出　　处：《云南水力发电》2020年第5期42-45,共4页Yunnan Water Power

摘　　要：通过国内相关文献研究成果,分析论证了桩基础在膨胀岩土内的上拔力受初始条件、含水率、土水特征曲线等因素的影响,无法给出准确的计算公式;进一步分析了桩土相对运动等,初步确定了膨胀土的中性点深度,结合经验及理论推导出了膨胀土侧摩阻力计算的半经验公式,并结合已有的相关文献测试结果进行了计算验证,实测值普遍比计算值偏低;采取工程措施及适宜的基础方案是有效降低膨胀土上拔力的方法,掏挖基础或人工挖孔桩基础可采取扣除中性点上桩长计算既可。Based on the research results of domestic and international literature,the paper analyzes and demonstrates that the effect of initial condition,water content,soil water characteristic curve on the pile foundation in expansive rock soil,and can not give accurate calculation formula.The relative motion of pile soil is further analyzed,the neutral point depth of expanded soil is preliminarily determined,and the semi-empirical formula for calculating the friction resistance of expanded soil is deduced based on experience and theory.According to the test results of related literatures,the measured values are generally lower than the calculated values.Engineering measures and appropriate foundation scheme are effective methods to reduce uplift force of expansive soil.Pile length on neutral point can be deducted for excavation foundation or manual excavation pile foundation.The parameters selection and semi empirical formula of expansive soil provided in this paper can provide engineering suggestions for the design of expansive soil pile foundation.

关 键 词：膨胀岩土 侧摩阻力 上拔力 中性点 抗拔桩 

分 类 号：TU475[建筑科学—结构工程] TU473.1[建筑科学—土工工程]