| 104 | 4 | 254 |
| 下载次数 | 被引频次 | 阅读次数 |
黏土是一种常用的路基填料。现场施工中，受降雨、蒸发等的影响，黏土路基填料通常在宽含水率范围下(包括最优含水率及其干湿侧)完成压实，形成情况各异的微观骨架，动力荷载作用下呈现出不同刚度特性。对5种压实含水率的黏土路基填料开展了动力回弹模量和微观结构研究，结果表明：当土体在最优含水率wopt及其干侧压实时，土骨架为团粒-团粒接触结构，孔隙分布呈现双峰特性；当土体在最优含水率wopt湿侧压实时，土骨架为颗粒-颗粒接触结构，孔隙分布呈现单峰特性。回弹变形ε1r和回弹模量Mr在不同压实含水率下随振次的变化规律相近，在加载初始阶段呈现迅速变化(减小/增大)的趋势，后随加载次数增加逐步趋于稳定。ε1r和Mr随压实含水率的增大分别呈现“倒钟型”和“钟型”的曲线变化趋势；特征含水率w-cha定义于曲线转折点处，将ε1r和Mr的变化分为2个阶段：当w
Clay soils were always used in the construction of road subgrade. During in-situ compaction, under the effects of the factors such as rainfal and evaporation, clay subgrade soils were usually compacted under a wide range of remoulding water content(optimum water content as well as its wet and dry sides). Thus, the microstructure of the compacted clay soils could change, leading to variations in stiffness property under cyclic loadings. The dynamic behavior and microstructure of compacted subgrade clay soils at various remoulding water contents were investigated. Results showed that: when compacted at wopt and its dry side, soil fabric was characterized by aggregate-aggregate contact structure with pore size distribution(PSD) exhibiting a bi-modal feature, while at wet side of wopt, soil fabric was characterized by particle-particle contact structure with an uni-modal PSD. The variations of resilient deformation ε1r and resilient modulus Mr with remoulding water content were similar, which varied rapidly at the initial loading stage and then tended to stabilize.The variations of ε1r and Mr with remoulding water content exhibited “inverted bell” and “bell” shapes, respectively. A characteristic remoulding water content was defined at the turning point of the curve, defining two stages of the variations of ε1r and Mr: when w
[1] 张军辉，张安顺，彭俊辉，等.循环荷载下路基黏土永久变形特性及力学模型[J].中国公路学报，2024,37(6):34-45.ZHANG J H,ZHANG A S,PENG J H,et al.Permanent deformation characteristics and mechanical modeling of roadbed clay under cyclic loading[J].Chnia Journal of Hignway and Transport,2024,37(6):34-45.(in Chinese)
[2] INAM A,ISHIKAWA T,MIURA S.Effect of principal stress axis rotation on cyclic plastic deformation characteristics of unsaturated base course material[J].Soils and Foundations,2012,52(3):465-480.
[3] 冯学茂，黄轩嘉，刘维正，等.湿化作用下高速公路红黏土路基动力特性现场试验研究[J].中国公路学报，2024,37(6):169-180.FENG X M,HUANG X J,LIU W Z,et al.Field test study on the dynamic characteristics of red clay subgrade of highway under wetting[J].Chnia Journal of Hignway and Transport,2024,37(6):169-180.(in Chinese)
[4] CAO Z G,CHEN J Y,CAI Y Q,et al.Effects of moisture content on the cyclic behavior of crushed tuff aggregates by large-scale triaxial test[J].Soil Dynamics and Earthquake Engineering,2017,95:1-8.
[5] LACKENBY J,INDRARATNA B,MCDOWELL G,et al.Effect of confining pressure on ballast degradation and deformation under cyclic triaxial loading[J].Géotechnique,2007,57(6):527-536.
[6] KHOURY N N,and ZAMAN M M.Correlation between resilient modulus,moisture variation,and soil suction for subgrade soils[J].Transportation Research Record,2004,1874(1):99-107.
[7] YANG S R,LIN H D,KUNG J H S,et al.Suction-controlled laboratory test on resilient modulus of unsaturated compacted subgrade soils[J].Journal of Geotechnical and Geoenvironmental Engineering,2008,134:1375-1384.
[8] CAO Z G,CHEN J Y,CAI Y Q,et al.Long-term behavior of clay-fouled unbound granular materials subjected to cyclic loadings with different frequencies[J].Engineering Geology,2018,243(4):118-127.
[9] WANG H L,CUI Y J,FRANCISCO L L,et al.Effects of inclusion contents on resilient modulus and damping ratio of unsaturated track bed materials[J].Canadian Geotechnical Journal,2017,54(12):1672-1681.
[10] VAN N A A,HOUBEN L J M,MOLENAAR A A A.Estimation of mechanical behavior of unbound road building materials from physical material properties[J].Proc.,5th Int.Conf.on the Bearing Capacity of Roads and Airfields,R.S.Nordal and G.Rafadal,eds,1998,3:1221-1223.
[11] DUONG T V,CUI Y J,TANG A M,et al.Effects of water and fines contents on the resilient modulus of the interlayer soil of railway substructure[J].Acta Geotechnica,2016,11(1):51-59.
[12] LIU J K,XIAO J H.Experimental study on the stability of railroad silt subgrade with increasing train speed[J].Journal of Geotechnical and Geoenvironmental Engineering,2010,136(6):833-841.
[13] XIAO J H,JUANG C H,XU C J,et al.Strength and deformation characteristics of compacted silt from the lower reaches of the Yellow River of China under monotonic and repeated loading[J].Engineering Geology,2014,178:49-57.
[14] West Conshohocken.Standard Test Method for Particle-Size Analysis of Soils:ASTM D422- 63[S].United States,2007.
[15] 中华人民共和国交通运输部.公路土工试验规程：JTG 3430—2020 [S].北京：人民交通出版社，2020.Ministry of Transport of the People's Republic of China.Test Methods of Soils for Highway Engineering:JTG3430—2020[S].Beijing:China Communication Press,2005.(in Chinese)
[16] TRINH V N,TANG A M,CUI Y J,et al.Mechanical characterisation of the fouled ballast in ancient railway track sub-structure by large-scale triaxial tests[J].Soils and Foundations,2012,52(3):511-523.
[17] LAMAS-LOPEZ F.Field and laboratory investigation on the dynamic behaviour of conventional railway track bed materials in the context of traffic upgrade[D].Pairs:Ecole des Ponts ParisTech,2016.
[18] PENUMADU D,DEAN J.Compressibility effect in evaluating the pore-size distribution of kaolin clay using mercury intrusion porosimetry[J].Canadian Geotechnical Journal,2000,37(2):393-405.
[19] DELAGE P,MARCIAL D,CUI Y J,et al.Ageing effects in a compacted bentonite:a microstructure approach[J].Géotechnique,2006,56(5):291-304.
[20] ZHANG T W,CUI Y J,FRANCISCO L L,et al.Compacted soil behaviour through changes of density,suction,and stiffness of soils with remoulding water content[J].Canadian Geotechnical Journal,2017,55(2):182-190.
[21] SU Y,CUI Y J,JEAN-CLAUDE D,et al.Developing a sample preparation approach to study the mechanical behavior of unsaturated fine/coarse soil mixture[J].Geotechnical Testing Journal,2021,44(4):912-928.
[22] SCHUBERT H.Tensile strength of agglomerates[J].Powder Technology,1975,11(2):107-119.
[23] LU N,KIM T,STRUE S,et al.Tensile strength of unsaturated sand[J].Journal of Engineering Mechanics,2009,135(12):1410-1419.
[24] TANG C S,PEI X J,WANG D Y,et al.Tensile Strength of Compacted Clayey Soil[J].Journal of Geotechnical and Geoenvironmental Engineering,2014,141(4):04014122.
[25] DELAGE P,MARCIAL D,CUI Y J,et al.Ageing effects in a compacted bentonite:a microstructure approach[J].Géotechnique,2006,56(5):291-304.
[26] LU N,LIKOS W J.Unsaturated soil mechanics[M].New York:Higher Education Press,2004.
基本信息:
DOI：10.19740/j.2096-9872.2024.05.08
中图分类号:U416.1
引用信息:
[1]亓帅,马伟,索智,等.压实含水率对黏土路基填料动力回弹模量影响研究[J].北京建筑大学学报,2024,40(05):66-73.DOI:10.19740/j.2096-9872.2024.05.08.
基金信息:
国家自然科学基金项目(52108295); 北京建筑大学“建大英才项目”(JDYC20220811)