深嵌岩桩承载特性及其荷载传递法应用  

Bearing Characteristics of Deep Rock-Socketed Piles and Application of Load Transfer Method

作　　者：龚成中[1,2] 何春林[1] 龚维明[2] 

机构地区：[1]淮阴工学院建筑工程学院,江苏淮安223001 [2]东南大学土木工程学院,南京210096

出　　处：《土木建筑与环境工程》2013年第4期84-88,共5页Journal of Civil,Architectural & Environment Engineering

基　　金：江苏省自然科学基金项目(BK2011406);山东省交通厅科技项目(2010Y-3)

摘　　要：为了弥补大直径深嵌岩桩(嵌岩比hr/b≥5)承载特性研究领域的不足,利用青岛海湾大桥试桩zh12的自平衡测试结果,对大直径深嵌岩桩的承载特性进行了分析。研究了深嵌岩桩嵌岩段实测的桩侧摩阻力与位移关系以及桩端阻力与位移关系,并与采用双曲线分布模式的荷载传递法进行了比较。研究结果表明:在软岩地区,大直径深嵌岩桩基桩顶处的荷载位移曲线为缓变型,近似为直线分布形态。从实测曲线的拟合结果来看,岩层处的侧摩阻力与位移关系采用双曲线拟合是可行的,参数1/b也能反映出桩侧极限摩阻力的数值;桩端岩层实测的荷载位移曲线也与双曲线形态比较相似;利用拟合曲线所得到的参数a、b反演计算所得到桩顶荷载位移曲线也与自平衡测试方法的实测结果接近。最后,根据实测结果分析了在不同单轴抗压强度状态下,桩侧极限摩阻力经验公式中参数α的取值范围。In order to study bearing characteristics of deep rock-socketed piles（hr/b≥5）,based on the test results of self-balancing test of zh12 pile in Qingdao Gulf Bridge,the bearing characteristics of deep rock-socketed piles were analyzed.The relation between sides shear resistance of the piles and its displacement socked in soft rock was researched,and the relation between end bearing resistance and displacement was studied.The hyperbolic distributions on the load transfer method were compared to them.The results indicate that Q-S curve of large diameter deep socketed pile in soft rock area declines slowly,approximately in linear distribution.According to the fitting curve based on measured results,it is feasible to fit the relationship between sides shear resistance and its displacement by using hyperbola.The parameter of 1/b also reflects the ultimate side resistance values of piles.The load-displacement curve at the top of pile is similar to the hyperbolic form.By using the parameters of a、b obtained from fitting curve,the calculated load-displacement curve on top of pile is close to the measured curve of self-balance method.At last,according to the measured results,the value range of parameterαin empirical formula was analyzed under different states of axial compressive strength.

关 键 词：桥梁工程 深嵌岩桩 荷载传递法 承载特性 桩侧摩阻力 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]