摘要
工程中,在群桩桩端注浆会对群桩承载特性产生一定影响。通过开展离心模型实验,对注浆和不注浆群桩在桩数和桩间距2个影响因素下的承载特性进行研究。研究结果表明:随着桩数的增加,桩端注浆提高桩基承载力的效果减弱;桩间距由3d增加到6d时,群桩承载力先增加后减小,在5d时达到最大;随桩间距的增大,群桩端阻比减小,侧阻比增加;群桩注浆后侧摩阻力增大,2×2群桩侧摩阻力沿桩身先增后减再增,3×3群桩沿桩身持续增大;桩间距为6d的注浆群桩,其桩侧摩阻力分布类似于注浆单桩。群桩注浆后,群桩效应系数减小,根据模型实验结果对未注浆群桩的群桩效应系数进行修正并用于注浆群桩承载力的计算,发现该方法计算注浆群桩极限承载力是可行的。
In engineering practices, pile-end grouting has a certain impact on the bearing characteristics of pile group. Through the centrifugal model test, the bearing characteristics of grouting and non-grouting pile groups under the influence of pile number and pile spacing were studied. The research shows that: with the increase of the number of piles, the effect of pile-end grouting to improve the bearing capacity of pile foundation is weakened. When the pile spacing increases from 3 d to 6 d, the bearing capacity of pile group increases first and then decreases, and the peak value isat 5 d. With the increase of pile spacing, the end resistance ratio of pile group decreases, the side resistance ratio increases. Pile side resistance of pile group after grouting increases, the pile side resistance of 2×2 pile group first increases, then decreases and then increases along the pile body, and that of3×3 pile group increases continuously along the pile body. The pile side resistance distribution of grouting pile group with pile spacing of 6 d is similar to that of single grouting pile. After grouting, the group pile effect coefficient decreases, so this paper modified the group pile effect coefficient of non-grouting group pile according to the results of model experiment, and applied it to the calculation of bearing capacity of grouting group pile. It is found that this method is feasible to calculate the ultimate bearing capacity of grouting group pile.
作者
李锋
王康超
朱珊珊
周志军
LI Feng;WANG Kangchao;ZHU Shanshan;ZHOU Zhijun(Shaanxi Provincial Communications Construction Group,Xi’an 710075,China;School of Highway,Chang’an University,Xi’an 710064,China;Shandong Construction Engineering Quality Inspection Center Co.,Ltd.,Jinan 250031,China)
出处
《铁道科学与工程学报》
CAS
CSCD
北大核心
2021年第12期3210-3218,共9页
Journal of Railway Science and Engineering
基金
国家重点研发计划项目(2018YFC0808606)。
关键词
桥梁工程
桩端注浆群桩
承载特性
离心模型试验
极限承载力
群桩效应系数
bridge engineering
pile-end grouting pile group
bearing characteristics
centrifugal model experiment
ultimate bearing capacity
group pile effect coefficient
