水平荷载作用下刚性桩桩土相互作用弱化规律和分布模式研究  

Studies on Pile-soil Interaction and Distribution Model of a Rigid Pile Under Horizontal Load

作　　者：孙永鑫 曲占斐 何春晖 王龙 王志鹏 SUN Yongxin;QU Zhanfei;HE Chunhui;WANG Long;WANG Zhipeng(Shandong Zhiyuan Electric Power Design Consulting Co.,Ltd.,Jinan 250000,China;State Grid Shandong Economic and Technological Research Institute,Jinan 250000,China)

机构地区：[1]山东智源电力设计咨询有限公司,山东济南250000 [2]国网山东省电力公司经济技术研究院,山东济南250000

出　　处：《山东电力技术》2024年第5期47-55,共9页Shandong Electric Power

基　　金：山东省自然科学基金项目(ZR2021QE259);山东智源电力设计咨询有限公司科技项目“水平循环受荷电力工程桩基竖向承载力弱化研究”(ZY-2022-01)。

摘　　要：目前,海上风力发电在中国发展非常迅速,“十四五”规划中我国海上风力发电装机容量将达到50 GW。超大直径单桩基础是当前全球海上风电场应用最为广泛的基础形式之一,占已建成海上风电场基础的75%。目前水平荷载对桩基竖向承载力的影响鲜有研究,桩周土压力水平是影响桩基竖向侧摩阻力的关键因素之一。为研究海上风电超大直径单桩基础水平承载特性,针对粉土中的刚性桩,开展了1 g模型试验,观察和分析水平荷载作用下的桩土相互作用弱化和沿桩身的分布规律,建立桩周土压力-变形弱化表达式,提出水平受荷后桩周土压力变化分布模式。结果表明:水平循环荷载作用下,随着循环次数的增加,主动区土压力逐渐降低,被动区土压力稍有增加;桩身发生水平变形后,主动区土压力变化可分为3个阶段,即急剧下降段、缓慢下降段和稳定阶段;桩身变形后,桩周土压力可沿桩身分为脱开区、弱化区、稳定区3个区域。Offshore wind power is currently developing very rapidly in China,and the installed capacity of offshore wind power in China will reach 50 GW in the 14th Five-Year Plan.Super large-diameter monopile foundation is one of the most common forms foundation,widely used in offshore wind farms in the world,accounting for 75 percent of the built offshore wind farm foundation.At present,the influence of horizontal load on the vertical bearing capacity of pile foundation has been rarely studied.The soil pressure level around the piles is one of the key factors affecting pile side friction resistance.To investigate the offshore super large-diameter monopile foundation’s lareral bearing behavior,a series of 1 g model tests were carried out for a rigid pile in silt,and the pile-soil weakening effect and distribution law along the pile were analyzed under lateral load.The expression of the soil pressure-deformation is established,and the distribution model of soil pressure along the pile shaft under lateral load is proposed.The test results reveal that the soil pressure in the active zone gradually decreases and that in the passive zone increases slightly with the increase of the cyclic number under horizontal cyclic load.After horizontal deformation of the pile,the soil pressure change in the active region can be divided into three phases:the sharp decline phase,the slow decline phase and the stable phase,and according to the soil pressure acting on the pile,there are three areas along the pile body:detachment zone,weakening zone and stabilizing zone.

关 键 词：水平循环荷载 刚性桩 桩土相互作用 土压力弱化模型 

分 类 号：TU43[建筑科学—岩土工程]