炭质页岩路基填料的路用性能研究  

Research on Road Performance of Carbonaceous Shale Subgrade Filler

作　　者：张孟金 黄亚飞 吴谦 毛雪松[3] 张建勋[3] 陈欣怡 王悦月 ZHANG Mengjin;HUANG Yafei;WU Qian;MAO Xuesong;ZHANG Jianxun;CHEN Xinyi;WANG Yueyue(China Railway Construction Yunnan Investment Co.,Ltd.,Kunming,Yunnan 650000,China;CCCC Frist Highway Consultants Co.,Ltd.,Xi’an,Shaanxi 710065,China;School of Highway,Chang’an University,Xi’an,Shaanxi 710064,China)

机构地区：[1]中铁建云南投资有限公司,云南昆明650000 [2]中交第一公路勘察设计研究院有限公司,陕西西安710065 [3]长安大学公路学院,陕西西安710064

出　　处：《中外公路》2024年第2期9-17,共9页Journal of China & Foreign Highway

基　　金：国家重点研发计划项目(编号:2021YFB2600103);中交第一公路勘察设计研究院有限公司科创基金项目(编号:KCJJ2020-14)。

摘　　要：炭质页岩用于路基填筑不仅能缓解炭质页岩分布区路基填料的供应难题,也符合中国基础设施建设“资源集约、节约”和“绿色化”的战略要求。然而,此类岩石性质软弱、易风化崩解、遇水强度衰减显著,充分利用须建立在深入认知其性质的基础上。该文研究炭质页岩原岩的基本性质;设计填料级配;进行填料的击实特性及击实后颗粒破碎特征研究、干湿循环条件下的RCBR(加州承载比)变化特征研究、干燥及浸水状态下填料的压缩性能及压缩后颗粒破碎特征研究以及浸水过程中路基回弹模量的现场测试。研究发现:随风化程度增加,原岩趋于黏土化,微观结构变得疏松。填料颗粒越粗,击实过程中越难调整自身位置来寻求稳定密实状态,颗粒破碎越显著。遇水后填料表现出较强的软化、崩解特性:初始RCBR为54%,随干湿循环呈现先快后慢的减小趋势,最终稳定在26%左右;压缩试验中,填料浸水后的湿化附加变形极为显著,颗粒破碎率大幅增加,最佳含水率状态下未发生破碎的粒组在浸水饱和后也发生了破碎;未浸水路基的回弹模量为140.4 MPa,浸水6 h后衰减至82.1 MPa,之后随浸水时间延长回弹模量衰减不再明显。实际应用时建议优化填料级配、控制最大粒径,采用能有效防水、控湿的路基结构,并避免将炭质页岩填料用于地表水、地下水发育部位。The application of carbonaceous shale for subgrade filling not only alleviates the shortage of subgrade filler in carbonaceous shale distribution areas but also meets the strategic requirements of“resource conservation and saving”and“green development”for infrastructure construction in China.However,such rocks are weak and susceptible to weathering and disintegration,and they exhibit significant strength deterioration when exposed to water.To fully apply them,their performance must be comprehensively understood.In this paper,the basic properties of the carbonaceous shale were studied,and filler gradation was designed.The tests on compaction characteristics of the filler and particle crushing characteristics after compaction,RCBR(California bearing ratio)variation characteristics under dry and wet cycle conditions,compression properties of the filler and particle crushing characteristics after compression under dry and wet conditions,as well as the rebound modulus of subgrade during water immersion were conducted.The results show that with an increasing degree of weathering,the original shale tends to become clayey,and the microstructure becomes loose.In the compaction process,coarser filler particles mean that they are more difficult to adjust their position to achieve a stable dense state,and particle crushing is more significant.The filler shows strong softening and disintegration properties when exposed to water.The initial RCBR of the filler is 54%,which exhibits a fast-to-slow decreasing trend under dry and wet cycles and finally stabilizes at about 26%.In the compression tests,additional deformation of the filler by wetting after water immersion is extremely significant,and the crushing particles increase greatly.Particle groups that do not crush at optimum water content also crush after saturation.The rebound modulus of the subgrade without water immersion is 140.4 MPa and declines to 82.1 MPa after 6 h of water immersion,after which the decay of the rebound modulus with increasing immersion time i

关 键 词：炭质页岩 路基填料 路用性能 浸水 干湿循环 颗粒破碎 

分 类 号：U416.12[交通运输工程—道路与铁道工程]