刚性桩复合地基增强体强度设计分析  

Analysis of Reinforcement Element Strength Design of Composite Ground Reinforced with Rigid Piles

作　　者：张东刚[1] 李涛[1] 张震[1] 陈耀光[1] 李帅[1] 

机构地区：[1]中国建筑科学研究院地基所,北京100013

出　　处：《建筑科学》2014年第3期13-17,21,共6页Building Science

基　　金：住房和城乡建设部软科学研究项目(20101602330740004)

摘　　要：增强体强度等级是复合地基设计的一个重要参数。增强体强度计算时需确定单桩承载力特征值,而单桩承载力特征值确定应同时满足复合地基承载力和变形要求,并取承载力和变形计算中确定的单桩承载力特征值的较大值作为增强体强度计算的依据;对高粘结强度桩,增强体采用商品混凝土时,桩身强度的确定不应采用混凝土立方体抗压强度平均值fcu,而应采用混凝土立方体抗压强度标准值fcu,k,即桩身强度计算公式应为fcu,k=4λRa/Ap。按照《建筑地基处理技术规范》(JGJ 79—2012)要求,复合地基工程验收时要求进行单桩静载荷试验,本文分析了静载荷试验中影响单桩承载力的因素,并给出复合地基设计计算时单桩承载力特征值取值的建议。The strength grade of reinforcement element is an important parameter in composite ground design. Firstly it has to determine the characteristic value of single pile bearing capacity which needs to meet the requirements of composite ground bearing capacity and deformation, and then the lager one of the characteristic values of single pile bearing capacity is adopted as the basis of the reinforcement element strength calculation. For high bond strength pile made by concrete, the design of pile strength should be based on standard compressive strength value of concrete cubes instead of average compressive strength value of concrete cubes, so the formula is fcu.k =4λRa/Ap. According to the requirement of Technical Code for Ground Treatment of Buildings, the single pile static load test should be conducted for composite ground acceptance. The influence factors of single pile bearing capacity in the test are analyzed in the paper, and the suggestion on selecting the characteristic value of single pile bearing capacity is given in composite ground design.

关 键 词：复合地基 增强体 桩身强度计算 标准值 检测 

分 类 号：TU470.3[建筑科学—结构工程]