珊瑚砂接触面剪切颗粒破碎特性研究  

A Characterization Study on Coral Sands Interface Shear Practice Breakage

作　　者：姚奇 余建民 郑红剑 魏厚振[2] 陈盼[2] 李幻 YAO Qi;YU Jianmin;ZHENG Hongjian;WEI Houzhen;CHEN Pan;LI Huan(College of Geosciences and Engineering,North China University of Water Resources and Electric Power,Zhengzhou,450046;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil,Mechanics,Chinese Academy of Sciences,Wuhan 430071;Wuhan Geocean Ocean Technology Co.Ltd.,Wuhan 430223)

机构地区：[1]华北水利水电大学地球科学与工程学院,郑州450046 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071 [3]武汉吉欧信海洋科技股份有限公司,武汉430223

出　　处：《土工基础》2023年第2期279-283,共5页Soil Engineering and Foundation

基　　金：湖北省技术创新专项(项目编号:2021BEC018)。

摘　　要：珊瑚砂与结构物的相互作用广泛存在于岛礁工程中,由于珊瑚砂强度低、易破碎,在受到荷载作用时,容易发生颗粒破碎致使接触面力学特性更复杂。通过珊瑚砂-钢板接触面环剪试验,并使用石英砂进行对比,揭示了珊瑚砂接触面剪切后颗粒破碎演化及颗粒形貌变化规律。结果表明:在相同的条件下,珊瑚砂产生小颗粒的含量明显高于石英砂,0.5~1 mm和1~2 mm粒径的珊瑚砂分别存在300 kPa和200 kPa的临界竖向压力,当竖向压力高于临界压力时,竖向压力对PSD曲线的影响明显降低。珊瑚砂与石英砂破碎率均随竖向压力增大而增加,且分别与竖向压力呈指数函数关系和线性关系。剪切后颗粒形貌由不规则向圆形发展,且竖向压力较大时,珊瑚砂与石英砂整体上颗粒形貌比较接近,都更趋于圆形。The interaction between the coral sand and structures widely exists in the island-reef engineering practices.Due to the low structural strength and fragility of coral sands,it is prone to the particle breakage under the external loads,resulting in more complicated mechanical properties of the interface.Through the ring shear tests of the coral sand-steel plate interface and the comparison with the quartz sand,the particle breakage evolution,and the particle shape change rule of the coral sand interface after the shear are revealed.The results show that,under the same conditions,the content of small particles produced by the coral sand is significantly higher than that of the quartz sand,and there is a critical vertical pressure of 300 kPa and 200 kPa for the coral sand with 0.5-1 and 1-2mm particle sizes,respectively.When the vertical pressure is higher than the critical pressure,the impact of the vertical pressure on the PSD curve is significantly reduced.The crushing rates of the coral sand and the quartz sand increase with the increase of the vertical pressure.The trends demonstrate an exponential function relationship and linear relationship with the vertical pressure respectively.After shearing,the particle shape develops from the irregular to rounded,and when the vertical pressure is large,the particle shape of the coral sand and the quartz sand is relatively close to each other,and both tend to be rounded.

关 键 词：珊瑚砂 石英砂 接触面 颗粒破碎 颗粒形貌 

分 类 号：TU411[建筑科学—岩土工程]