砂-结构界面剪切机理及细观行为演化研究

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国家科技期刊平台
NETL
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中文摘要：[目的]粗糙度和粒径是影响砂土地基桩侧摩阻力的关键因素，探究其对界面宏观力学特性和细观剪切机理的影响具有重要意义。[方法]利用改进的直剪设备，研究了考虑结构物表面纹理宽度与颗粒粒径影响的钢-砂界面宏观剪切性状和内在变化机理，借助PFC软件研究了界面细观行为演化规律。[结果]结果表明:细砂和中砂粒组的界面峰值剪切应力随纹理宽度增大而增加，粗砂粒组则呈现先增加后减小的变化规律;在纹理宽度与砂粒径的不同相对尺寸关系下，界面剪切机理与砂-砂剪切、颗粒-纹理嵌锁作用及纹理棱角阻碍作用密切相关;光滑界面的摩擦角随粒径增大而减小，粗糙界面的摩擦角基本与粒径成正比例关系;配位数和受界面剪切影响的颗粒范围随粒径的增大而增加，粒径较大的砂颗粒在试验中后期的界面处出现力链断裂现象。[结论]纹理的设计能够显著提升界面抗剪强度，具有粗糙纹理的桩表面更有利于中、粗砂地基桩基承载力的发挥。

外文标题：Study on shear mechanism and microscopic behavior evolution of sand-structure interface

外文摘要：[Objective]Roughness and particle size are the key factors affecting the side friction of piles in sandy soil,and explo-ring their effects on the macroscopic mechanical properties and microscopic shear mechanisms of the interface is of great signifi-cance.[Methods]Using the improved direct shear equipment,the macro shear behavior and internal change mechanism of the interface between steel and sand considering the influence factors of the groove width and particle size are studied.The evolution law of interface microscopic behavior was studied using PFC software.[Results]The result show that the interface peak shear stress of fine sand and medium sand group increases with the groove width,while that of coarse sand group increases first and then decreases.Under the different relative size relationships between texture width and sand particle size,the interface shear mechanism is closely related to sand-sand shearing,grain-groove interlocking and grain angular blocking.The friction angle of smooth interface decreases with the particle size,while the friction angle of rough interface is basically proportional to the particle size.The coordination number and the range of particles affected by interface shear increase with the particle size.The larger sand particles appear force chain fracture near the interface in the middle and later stages of the test.[Conclusion]Groove design can significantly improve the shear strength of the interface,and the pile surface with rough groove is more conducive to exerting the bearing capacity of the pile in medium and coarse sand soil foundation.

外文关键词：

steelsandparticle sizegrooverelative sizeshear mechanismmicroscopic behaviormechanical propertiesdeformation

作者：

马永明、郭聚坤、王瑞、左珅、李晋、魏道凯

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作者单位：

山东交通学院交通土建工程学院,山东济南 250357

山东交通职业学院公路与建筑系,山东潍坊 261206

长安大学公路学院,陕西西安 710064

宁夏大学土木与水利工程学院,宁夏银川 750021

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关键词：

钢砂粒径纹理剪切机理细观行为力学性能变形

基金：

山东省自然科学基金青年项目山东省交通运输科技项目山东交通学院研究生科技创新项目国家自然科学基金项目

项目编号：

ZR2020QE2572020B232022YK02241572275

出版年：

2024

DOI：

10.13928/j.cnki.wrahe.2024.07.016

水利水电技术(中英文)

水利部发展研究中心

水利水电技术(中英文)

CSTPCD北大核心

影响因子：0.456

ISSN：1000-0860

年,卷(期)：2024.55(7)