剪切模式对砂-钢界面特性的影响  

Influence of Shear Mode on Sand-Steel Interface Characteristics

作　　者：张迪[1] 徐孟涛 孙峰[1] 曹刚 李佳豪 ZHANG Di;XU Mengtao;SUN Feng;CAO Gang;LI Jiahao(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China;College of Architecture and Civil Engineering,Zhejiang University,Hangzhou 310058,China;Hangzhou Fuyang City Construction Investment Group Co.,Ltd.,Hangzhou 311499,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063 [2]浙江大学建筑工程学院,杭州310058 [3]杭州富阳城市建设投资集团有限公司,杭州311499

出　　处：《船舶工程》2024年第7期175-181,共7页Ship Engineering

摘　　要：针对海上风机导管架基础在安装过程中发生的桩土界面单向剪切行为和服役过程中发生的持续循环剪切行为,分别采用常应力和等刚度边界条件对石英砂/钙质砂开展单向和循环剪切试验,研究不同剪切模式下界面强度发挥的细观作用。结果发现:随着单向剪切距离的增加,土样破碎带厚度逐渐增大,钢界面粗糙度下降;循环剪切幅值越大,颗粒排布重塑越充分,产生的法向位移越大。在大位移单向剪切和循环剪切过程中,破碎带的存在会改变土体的初始结构,使其具有强烈方向性。由于钙质砂的硬度较低,同等粒径下其形状相比石英砂颗粒更不规则,因此其在同等剪切距离下会产生更大的破碎量,引起较大体缩,而破碎后的石英砂棱角较多,在钢界面扰动下更易发生旋转,引起大位移单向剪切后的循环剪切过程中土样剪胀增加。Due to the wide application and robust stability,the jacket foundation has emerged as a predominant form for offshore wind turbine foundations.This study addresses the unidirectional shear behavior at the pile-soil interface during the installation of jacket foundations and the cyclic shear behavior encountered during service.A series of interface shearing tests were conducted on quartz sand and calcareous sand under constant stress and constant stiffness boundary conditions.Both unidirectional and cyclic shear tests were performed to assess the impact of shear mode on the sand-steel interface properties.The findings revealed that with an increase in unidirectional shear distance,the thickness of the soil breakage band gradually increases,while the roughness of the steel surface decreases.Larger cyclic shear amplitudes lead to more pronounced rearrangement of soil particles and greater normal displacement.In the process of large displacement unidirectional shearing and cyclic shearing,the breakage band alters the soil's initial interlocking,imparting a strong directionality.Due to the lower hardness of calcareous sand,its particles are more irregular compared to quartz sand of the same size,leading to greater crushing and volumetric shrinkage at same shear distance.After crushing,quartz sand develops more angular edges,making it more prone to rotation under the disturbance of steel surface,thereby increasing the dilation of the soil sample during the cyclic shearing after the large displacement unidirectional shearing.

关 键 词：导管架基础 界面环剪仪 剪切模式 破碎带 界面特性 

分 类 号：TU47[建筑科学—结构工程]