砂-粉混合料颗粒接触状态的临界条件确定  

Procedure for characterizing the critical particle contact state of sand-fines mixtures

作　　者：吴琪[1,2] 孙苏豫 杭天柱 赵凯 陈国兴[1,2] WU Qi;SUN Suyu;HANG Tianzhu;ZHAO Kai;CHEN Guoxing(Institute of Geotechnical Engineering,Nanjing Tech University,Nanjing 210009,China;Civil Engineering and Earthquake Disaster Prevention Center of Jiangsu Province,Nanjing 210009,China)

机构地区：[1]南京工业大学岩土工程研究所,江苏南京210009 [2]江苏省土木工程防震技术研究中心,江苏南京210009

出　　处：《哈尔滨工程大学学报》2024年第2期277-283,297,共8页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(52008206,51978334,51608267);国家重点研发计划(2018YFC1504301)。

摘　　要：砂-粉混合料被广泛应用于高速铁路路基、人工筑岛及海底沉管隧道垫层等重大工程,如何科学地表征砂-粉混合料复杂的颗粒接触状态及连续演变的力学行为特征,并深入揭示其对混合料静/动力学特性的影响已是一项紧迫的基础性科学研究任务。本文基于代表性砂-粉混合料的基本物理性能指标及力学特性指标试验数据,验证Rahman等提出的区分“细粒填充砂粒”和“砂粒悬浮细粒”的阈值细粒含量FCth半经验公式预测能力。基于理想二元介质材料的理论最小孔隙比计算方法,提出确定中间性态土颗粒接触状态临界条件参量FC_(in-min)和FC_(in-max)的方法,分析各参数对FC_(in-min)和FC_(in-max)的影响规律,建立基于基本物理性能指标的FC_(in-min)和FC_(in-max)预测方法,最终提出全FC范围(FC=0~100%)的砂-粉混合料各颗粒接触状态临界条件参量的有效评价方法。Sand-fines mixtures are widely applied in key projects such as high-speed railway roadbeds,artificial is-land buildings,and submarine immersed tube tunnel cushions.Characterizing the complex particle contact state and mechanical behavior evolution of the sand-fines mixtures and disclosing their influence on the static/dynamic properties of the mixtures are one of critical and urgent scientific problems.The capability of the Rahman semiem-pirical formula to predict the threshold fines content FCth,which differentiates the regime of“fines in sand”(sand-dominated behavior)from“sand in fines”(fines-dominated behavior),is confirmed using the basic indexes of the physical properties and mechanical properties of the mixtures published in the literature.In this study,a new meth-od for determining the critical particle contact condition parameters FC_(in-min)and FC_(in-max)of in-transition soils is de-veloped based on the theoretical minimum void ratio calculation method of binary medium materials(binary packing model).The influencing laws of every parameter on FC_(in-min)and FC_(in-max)are analyzed,and the prediction meth-od for FC_(in-min)and FC_(in-max)is developed based on the basic physical performance index.Finally,an effective evalu-ation procedure of the critical condition parameters under every particle contact state of sand-fines mixtures in the full FC range(FC=0%~100%)is presented.

关 键 词：细粒含量 砂-粉混合料 颗粒接触状态 阈值细粒含量 临界条件参量 理论最小孔隙比 二元介质模型 中间性态 

分 类 号：TU441[建筑科学—岩土工程]