堆载作用下楔形桩负摩阻力演化特性研究  

RESEARCH ON THE EVOLUTION CHARACTERISTICS OF NEGATIVE FRICTIONAL RESISTANCE OF WEDGE-SHAPED PILES UNDER OVERLOAD

作　　者：孙松强 刘斌 王志远 朱美甜 李晓梦 Sun Song-qiang;Liu Bin;Wang Zhi-yuan;Zhu Mei-tian;Li Xiao-meng

机构地区：[1]浙江华东工程建设管理有限公司,杭州310030 [2]郑州科技学院,郑州450064

出　　处：《建筑技术开发》2024年第7期92-94,共3页Building Technology Development

基　　金：河南省科技攻关计划(222102320404);中国电建集团华东勘测设计研究院有限公司横向委托项目(22010122004)。

摘　　要：通过分析地面堆载因素造成的桩周土体沉降所引起负摩阻力的特性,对了解与掌握桩基负摩阻力特性具有重要的理论意义,但如何减轻堆载引起的负摩阻力,对工程更有实际意义。研究采用FLAC 3D有限差分法,分析了堆载作用对楔形桩基负摩阻力和中性点的影响,研究结果表明:无论堆载大小,楔形桩桩身轴力随深度的增大而增大,待其达到某一峰值时,桩身轴力减小。当桩周土堆载不大于7.5 kPa时,随着堆载的增大,轴力也随之明显增大;而当桩周土堆载大于7.5 kPa时,随着堆载的增大,轴力虽然也略有增大,但其增长幅度较小。堆载作用下楔形桩中性点稳定深度为–0.3~–0.4 m间。当桩周土堆载较大时,可采用轴力最大点、摩阻力零值、相对位移零值计算中性点位置;而当堆载较小时,则利用轴力最大点和摩阻力零值计算中性点位置更为可靠。Analyzing the characteristics of negative frictional resistance caused by soil settlement around piles due to ground loading factors is of great theoretical significance for understanding and mastering the characteristics of negative frictional resistance of pile foundations.However,how to reduce the negative frictional resistance caused by loading is more practical for engineering.The study used FLAC 3D finite difference method to analyze the effect of pile loading on the negative friction and neutral point of wedge-shaped pile foundation.The research results showed that regardless of the size of pile loading,the axial force of the wedge-shaped pile body increased with the increase of depth.When it reached a certain peak,the axial force of the pile body decreased.When the soil pile load around the pile is not greater than 7.5kPa,the axial force also increases significantly with the increase of the pile load;When the soil pile load around the pile is greater than 7.5kPa,as the pile load increases,although the axial force also slightly increases,its growth rate is relatively small.The stable depth of the neutral point of the wedge-shaped pile under pile loading is between–0.3 and–0.4m.When the soil around the pile is heavily loaded,the neutral point position can be calculated using the maximum axial force point,zero frictional resistance value,and zero relative displacement value;When the pile load is small,it is more reliable to calculate the neutral point position using the maximum axial force point and the zero frictional resistance value.

关 键 词：楔形桩 负摩阻力 中性点 相对位移 有限元 

分 类 号：TU447[建筑科学—岩土工程]