基于模型试验的陡坡段基桩水平循环响应特性分析  

Analysis on Cyclic Lateral Response Characteristics of Piles in Sloping Ground Based on Model Experiments

作　　者：杨超炜[1] 彭文哲 陈玖颖 YANG Chaowei;PENG Wenzhe;CHEN Jiuying(College of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2022年第7期130-137,共8页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(52108317,51908208)。

摘　　要：为探究陡坡段桥梁基桩水平循环响应特性,设计并开展了不同循环次数、荷载幅值和坡度条件下的水平循环受荷陡坡段基桩模型试验.通过对比实测弯矩推导的地基反力分布与实测地基反力分布,验证了实测数据的可信性,进而分析了桩顶水平位移、桩顶偏转角、桩身弯矩及地基反力分布的演化规律.结果表明:桩顶水平位移由弹性变形和塑性变形组成,弹性变形基本保持不变,塑性变形随循环次数的增加而非线性增大,增加率逐渐减小,即塑性安定;桩顶无量纲位移和桩顶转角均随循环次数的增加而非线性增大,且桩顶无量纲位移的上包络线均可用幂函数y/D=An拟合;陡坡段基桩的单向水平循环响应主要受前100次循环加载影响;桩身最大弯矩和最大地基反力均随荷载幅值和坡度的增大而增大,二者的位置均随坡度增大而下降,但几乎不受荷载幅值影响.To investigate the cyclic lateral response characteristics of bridge pile foundations in sloping ground,model experiments of piles in sloping ground under different cycle numbers,load amplitudes and slope angles were carried out. The accuracy of measurement results was validated by the comparisons between the measured subgrade reaction profiles and those derived by measured bending moment profiles,and then the evolutions of pile head deflection,rotation at the pile head,bending moment and subgrade reaction profiles were revealed. The measurement results show that the pile head deflection is composed of elastic deformation and plastic deformation,in which the elastic deformation almost remains unchanged and the plastic deformation nonlinearly increases with cycle numbers at a decreasing rate,that is the plastic shakedown. The dimensionless pile head deflection and rotation atop the pile nonlinearly increase with cycle numbers,and the upper envelopes of the former can be fitted by power functions y/D=An. The one-way cyclic lateral responses of piles in sloping ground are mainly affected by the first 100 cyclic lateral loadings. The maximum bending moment and subgrade reaction increase with the load amplitude and slope angle,and their locations fall with the increase of slope angle but are rarely affected by the load amplitude.

关 键 词：岩土工程 桩基础 水平循环荷载 陡坡效应 模型试验 

分 类 号：TU473[建筑科学—结构工程]