不同含水率下级配碎石振动压实状态评价与机理研究  

Evaluation and Mechanism Study of Vibration Compaction State of Graded Gravel under Different Moisture Content

作　　者：谢康 李泰灃 肖宪普 陈晓斌[2] 张千里 王业顺 XIE Kang;LI Taifeng;XIAO Xianpu;CHEN Xiaobin;ZHANG Qianli;WANG Yeshun(Railway Engineering Research Institute,China Academy of Railway Sciences Co.,Ltd.,Beijing 100081,China;School of Civil Engineering,Central South University,Changsha 410075,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]中南大学土木工程学院,湖南长沙410075 [3]石家庄铁道大学土木工程学院,河北石家庄050043

出　　处：《铁道学报》2024年第2期150-158,共9页Journal of the China Railway Society

基　　金：国家重点研发计划(2022YFB2603400)。

摘　　要：以重锤击实法中的最优含水率为高速铁路基床级配碎石振动压实法中含水率确定标准,振动压实过程中产生冒泥现象,劣化了级配碎石的压实质量。为研究含水率对振动压实法的影响机制,以不同土体结构类型的级配碎石为研究对象,通过大型室内振动压实和三轴试验,分析不同含水率级配碎石的压实状态变化规律。研究结果表明,干密度随着含水率的增大呈先减小后增大的趋势,存在波谷,且含水率过高时,振动压实中会出现粗粒料黏着、冒泥等现象;采用压实烘干后,临界含水率作为振动压实法的加水量,压实中未产生翻浆现象,且干密度满足现场碾压标准;临界含水率下CEI和TDI处于最佳区间,颗粒破碎率最低,同时保证压实后填料的刚度、强度最大;基于临界状态土力学理论,解释孔隙水对填料振动压实的影响,即在含水率超过临界含水率后、外界总应力保持不变的情况下,孔隙水压力增大,土体有效应力减小,导致成型后填料强度下降。研究成果可为高速铁路粗粒土填筑控制提供理论参考。When the optimal moisture content in the heavy hammer compaction method is used as the standard for determining the moisture content in the vibratory compaction method for graded aggregates for high speed railway subgrade,the phenomenon of"mud bubbling"during vibratory compaction deteriorates the compaction quality of the graded aggregates.In order to study the effect and mechanism of moisture content on vibration compaction method,the graded crushed stones with different soil structure types were taken as the research object.Through large-scale indoor vibratory compaction and triaxial tests,the change law of compaction state was discussed and analyzed.The results show that:The extreme dry density first decreases before increasing with the increase of water content,with a wave trough and high moisture content.During vibration compaction,phenomena such as coarse aggregate adhesion and mud bubbling will occur.When the critical moisture content after compaction and drying is used as the water addition amount for the vibration compaction method,no mud bubbling phenomenon occurs during compaction,with the dry density meeting the requirements of on-site compaction.The critical water content keeps CEI and TDI in the optimal range,with the lowest particle breakage rate,and the maximum stiffness and strength of the compacted filler.Based on the theory of soil mechanics in the critical state,the effect of pore water on the vibration compaction of the filler is explained.That is,when the moisture content exceeds the critical moisture content and the total external stress remains unchanged,the pore water pressure increases and the effective earth pressure decreases,resulting in a decrease in the strength of the filler after molding.The research results can provide a theoretical reference for the control of high-speed rail coarse-grained soil filling.

关 键 词：高速铁路路基 振动压实 临界含水率 智能压实 压实机理 

分 类 号：U215[交通运输工程—道路与铁道工程]