考虑不同固结阶段条件下旧桩承载力的预测研究  

Prediction of Old Pile Bearing Capacity Under Different Consolidation Stages

作　　者：苏聪 李镜培[1,2] 谢峰 SU Cong;LI Jingpei;XIE Feng(Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]同济大学地下建筑与工程系,上海200092

出　　处：《结构工程师》2022年第3期123-130,共8页Structural Engineers

基　　金：国家自然科学基金(41972274)。

摘　　要：旧桩再利用是实现绿色建造和促进桩基工程技术进步的有效途径。为了在实际工程中应用旧桩设计理论,降低计算复杂度,定义了承载力时效系数来表示承载力的时效性并提出了时效系数的简化计算方法。该方法将主固结与次固结阶段相结合,建立了综合考虑两阶段影响的承载力简化计算方法。针对主固结阶段超孔隙水压力消散导致承载力增长,提出了半经验半理论简化计算公式;针对次固结阶段孔隙比减少导致承载力增长,提出了相应简化计算公式,并对简化公式进行了实例验证与参数分析。通过实例进行计算验证,结果表明,本文的简化计算方法与实测数据吻合较好,在一定程度上反映了承载力变化的内在机理。The utilization of old piles is an effective way to achieve green construction and promote the technological progress of pile foundation engineering.In order to apply the design theory of old piles in actual projects,reducing computational complexity,a time-effect coefficient of bearing capacity is defined and a simplified calculation method of the time-effect coefficient is proposed.This method combines the main consolidation and secondary consolidation stages,considering the influence of both stages comprehensively.A semi-empirical and semi-theoretical simplified calculation formula is proposed considering the idea that the excess pore water pressure dissipates during the main consolidation stage to increase the bearing capacity According to the idea that the reduction of pore ratio leads to an increase of bearing capacity in the secondary consolidation stage,a simplified calculation formula is proposed,and the simplified formula is verified by examples and parametric analysis is conducted.A field test is used for verification,and the results show that the simplified calculation method proposed in this paper is in good agreement with the measured data and reflects the variation mechanism of the bearing capacity to a certain extent.

关 键 词：承载力时效性 简化计算 超孔隙水压力 主固结 次固结 

分 类 号：TU473.1[建筑科学—结构工程]