摘要
为探究礁灰岩地层中钻孔灌注嵌岩桩的桩-岩界面剪切作用规律,试验选取南海某岛礁的块状结构、砾块结构、砾屑结构及砂屑结构礁灰岩岩芯,开展室内物理力学性质试验及常法向应力条件下的礁灰岩-混凝土界面剪切强度试验研究,探究桩-岩界面剪应力-剪切位移关系曲线的变化规律。开展红砂岩-混凝土界面剪切对比试验,揭示两种不同沉积作用类型的岩石与混凝土黏结面产生剪切强度差异的根本原因。试验结果表明:礁灰岩-混凝土界面的剪切强度受礁灰岩的结构类型、桩-岩强度比等因素影响;由于水泥浆在礁灰岩中的扩散填充作用,礁灰岩-混凝土界面的黏结力和内摩擦角均高于砂岩-混凝土界面;桩-岩强度比产生的界面剪切强度响应受礁灰岩结构类型的影响,低桩-岩强度比时,块状结构、砾块结构礁灰岩-混凝土界面的黏结力均高于高强度比条件;桩-岩强度比增大,块状结构礁灰岩-混凝土界面的内摩擦角增加,而砾块结构礁灰岩-混凝土界面的内摩擦角变化不大。
This project planed to investigate the law of shear action in pile-rock interface of bored rock-socketed pile in reef limestone stratum.For this purpose,the shear test,physical and mechanic property test were performed on the four structure types of reef limestone core samples including framestone,bindstone,rudstone and bioclastic limestone which were sampled from a certain core reef in South China sea.In this way,the variation law of shear stress-shear displacement curve of pile-rock interface was explored.Meanwhile,shear test on the interface between red sandstone and concrete was also carried out to reveal the basic reason for the difference of shear strength between two different sedimentary types of rock and concrete bond surfaces.Based upon these,the investigation suggested that shear strength of reef limestone-concrete interface was affected by the structure type of reef limestone and the strength ratio of pile-rock interface.As a result of the diffusive filling effect of cement slurry in reef limestone,the cohesive force and internal friction angle of the interface between reef limestone and concrete were both larger than those of sandstone-concrete interface.The shear strength response of the strength ratio of pile-rock interface was influenced by the type of reef limestone structure.Cohesive force of the limestone-concrete interface of framestone and bindstone were both larger at a small strength ratio of pile-rock interface than that at a large strength ratio.Internal friction angle of the interface between framestone and concrete was bigger at a large strength ratio of pile-rock interface than that at a small strength ratio while this index changed little in the bindstone-concrete interface.
作者
刘海峰
朱长歧
汪稔
王新志
崔翔
王天民
LIU Hai-feng;ZHU Chang-qi;WANG Ren;WANG Xin-zhi;CUI Xiang;WANG Tian-min(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of the Chinese Academy of Sciences,Beijing 100049,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2020年第5期1540-1548,共9页
Rock and Soil Mechanics
基金
中国科学院战略性先导科技专项(A类)(No.XDA13010201,No.XDA13010301)
国家自然科学基金项目(No.41877271)。
关键词
珊瑚礁灰岩
嵌岩桩
界面剪切
结构类型
强度比
coral reef limestone
rock-socketed piles
interface shear test
structural types
strength ratio
