摘要
对于地基平板载荷试验,《建筑地基检测技术规范》(JGJ340-2015)推荐的载荷板尺寸、现场检测惯用尺寸和基础实际尺寸之间往往存在明显差异,从而导致地基承载力判定存在分歧。基于现场试验成果,建立有限元模型并验证了其可靠性,分析了不同载荷板宽下均质土地基和双层土地基承载力和变形的尺寸效应以及现场试验用反力支墩的影响。针对按相对变形判定地基承载力时存在的问题,分析了载荷板宽度限值对承载力判定结果的影响。结果表明:不同载荷板宽下,均质土地基的承载力变化缓慢而沉降变化明显;上软下硬双层土地基的承载力随载荷板宽增加而提高,沉降量减小;支墩影响会使判定的承载力增大。现行检测规范按相对变形标准判定承载力时,限定板宽会使尺寸效应显著增加,板宽上限由2.0 m调整为3.0 m较为合理。
In field plate loading tests for the ground,the recommended size specified in the Technical Code for Testing of Building Foundation Soils(JGJ 340―2015),the commonly used size,and the actual size of the foundation often differ significantly,leading to discrepancies in determining the ground bearing capacity.A finite element model was established based on the results of the field tests to validate its reliability.Subsequently,the model was utilized to study the size effect on bearing capacity and deformation of both homogeneous and double-layered soil foundations under loading plates of varying widths.Furthermore,the impact of the reaction pier employed in the field test was analyze.The results indicate that with varying widths of the loading plate,the bearing capacity of homogeneous ground undergoes gradual changes,accompanied by noticeable settlement increments.The bearing capacity of double-layered ground,with a soft upper layer and a hard lower layer,increases with the width of the loading plate,resulting in reduced settlement.The presence of the reaction pier enhances the determination of bearing capacity.In the current testing code,the bearing capacity determined by ground relative deformation shows a significant size effect when the loading plate width is limited.It is recommended to adjust the upper limit of the loading plate width from 2.0 m to 3.0 m.
作者
杨立
YANG Li(Shenzhen Building Safety and Construction Quality Testing and Appraisal Center,Guangdong,Shenzhen 518052,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2024年第S01期723-730,共8页
Rock and Soil Mechanics
关键词
平板载荷试验
尺寸效应
数值模拟
地基承载力
宽度修正
field plate loading test
size effect
numerical simulation
ground bearing capacity
width correction
