斜坡段水平循环受荷单桩变形特性试验及分析模型  

Experimental and Analytical Model for Deformation Characteristics of a Cyclic Laterally Loaded Pile in Sloping Ground

作　　者：张玲[1,2,3] 岳梢 赵明华 李琼[1,2,3] 彭文哲 ZHANG Ling;YUE Shao;ZHAO Ming-hua;LI Qiong;PENG Wen-zhe(College of Civil Engineering,Hunan University,Changsha 410082,Hunan,China;Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education,Hunan University,Changsha 410082,Hunan,China;National International Joint Research Center for Building Safety and Environment,Hunan University,Changsha 410082,Hunan,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]湖南大学建筑安全与节能教育部重点实验室,湖南长沙410082 [3]湖南大学国家级建筑安全与环境国际联合研究中心,湖南长沙410082

出　　处：《中国公路学报》2024年第10期128-138,共11页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(52078205,52108317);湖南省自然科学基金项目(2020JJ3013);湖南省交通运输厅科技项目(201414)。

摘　　要：斜坡单桩基础承受车辆、风及波浪等水平循环荷载作用时,受力变形特性极为复杂。首先,开展砂土地基中不同坡度及循环次数下斜坡单桩水平循环加载模型试验,并与静载试验结果对比,分析斜坡效应及循环效应双重作用下的单桩累积变形特性;其次,通过建立折减深度及折减系数随坡度正切值tan(θ)变化的函数关系,对m法进行修正,提出水平循环荷载作用下斜坡单桩受力变形矩阵传递计算方法,并初步分析循环效应的影响深度及各坡度下比例系数m值的循环弱化规律。结果表明:各坡度下的单桩循环荷载-位移曲线呈明显的位移累积与非线性滞回耗能特征;斜坡效应会进一步放大循环效应下的累积位移;累积位移随循环次数N呈三阶段变化特征,且与循环次数N及坡度θ之间满足幂函数a(θ)N^(b)关系;比例系数m值随N变化特征同累积位移,呈三阶段,且存在循环效应影响深度。The deformation characteristics of piles under cyclic lateral loading(such as vehicle,wind,or wave loads)in sloping ground are extremely complex.This study accordingly conducted cyclic lateral loading tests of model piles in sandy ground with different slope angles and compared the deformation results with those of static load tests to analyze the cumulative deformation characteristics of the piles.The deformation calculation method was subsequently modified to account for the effective depth reduction using a reduction factor defined as a function of the change in the tangent of the slope,tan(θ).Next,a matrix transfer method for calculating the stress and deformation behavior of piles in sloping ground under cyclic lateral loading was proposed and applied to conduct a preliminary analysis of the depth of influence of the cyclic effect and the cyclic weakening law according to the scale factor m for each slope.The results indicate that the cyclic load-displacement curves of the piles at each slope angle are characterized by significant displacement accumulation and non-linear hysteretic energy dissipation;the slope effect further amplifies the accumulated displacement under the cyclic effect;the cumulative displacement is characterized by a three-stage variation with the number of cycles N according to the power function a(θ)N^(b);the value of m varies in three stages with N in the same manner as the cumulative displacement;and there is a cyclic effect on the depth to which the value of m is influenced.

关 键 词：桥梁工程 桩基础 M法 斜坡效应 循环荷载 模型试验 分析模型 

分 类 号：U443.1[建筑科学—桥梁与隧道工程]