| 分层铺筑与反挖试验条件下级配碎石结构模量特性 |
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| 引用本文： | 吕松涛,郑国志,吴政达,夏诚东,刘超超,樊国鹏,李喆,黄爱军.分层铺筑与反挖试验条件下级配碎石结构模量特性[J].中国公路学报,2022,35(12):1-11. |
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| 作者姓名： | 吕松涛 郑国志 吴政达 夏诚东 刘超超 樊国鹏 李喆 黄爱军 |
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| 作者单位： | 1. 长沙理工大学 交通运输工程学院, 湖南 长沙 410114;2. 长沙理工大学 国际工学院, 湖南 长沙 410114;3. 内蒙古自治区交通建设工程质量监测鉴定站, 内蒙古 呼和浩特 010050;4. 深圳市市政工程总公司, 广东 深圳 518034 |
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| 基金项目： | 国家自然科学基金项目(52078063);国家重大科研仪器研制项目(51927814)； 国家自然科学基金杰出青年基金项目(52225806)* |
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| 摘 要： | 为了客观揭示级配碎石模量的结构服役状态相关性，采用室内动三轴材料试验和足尺结构试验开展级配碎石的模量特性研究，室内动三轴试验通过控制含水率、密实度、围压及偏应力等指标探究级配碎石在不同服役状态下的动回弹模量。研究发现，级配碎石的动回弹模量随着含水率的增大而减小，随着密实度、围压及偏应力的增大而增大。采用承载板和便携式落锤弯沉仪(PFWD)测试方法，通过分层铺筑与反挖2种室外足尺试验对级配碎石层顶面当量模量及该层结构模量进行测试与对比分析。分层铺筑测试结果表明：采用承载板法和PFWD方法测试得到级配碎石顶面当量模量和其结构模量均随铺筑层厚度的增加而增加，但增长速度随铺筑厚度增大而减小；级配碎石顶面模量随着下承层的顶面当量模量的增大而增大，但增长速度逐渐降低。反挖测试结果表明，由于上部级配碎石层的影响，反挖处级配碎石顶面当量模量先增加后减小，在开挖深度为20 cm时达到峰值，随着开挖深度的增加逐渐降低，但降低速度逐渐减小。对比室内三轴材料试验和足尺现场结构试验结果发现，级配碎石在足尺路面结构中的结构模量大于其三轴试验测试结果，将三轴模量测试结果用于路面结构设计将低估其承载能力，并产生较大的设计偏差。反挖方法同时考虑了下承层与上覆结构层自重及摩擦力的影响，与其实际服役条件相符。
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| 关 键 词： | 道路工程 级配碎石 分层铺筑 反挖 模量 |
| 收稿时间： | 2021-11-01 |
Structural Modulus of Graded Aggregate Under Layered Paving and Excavation Test Conditions |
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| LYU Song-tao,ZHENG Guo-zhi,WU Zheng-da,XIA Cheng-dong,LIU Chao-chao,FAN Guo-peng,LI Zhe,HUANG Ai-jun.Structural Modulus of Graded Aggregate Under Layered Paving and Excavation Test Conditions[J].China Journal of Highway and Transport,2022,35(12):1-11. |
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| Authors: | LYU Song-tao ZHENG Guo-zhi WU Zheng-da XIA Cheng-dong LIU Chao-chao FAN Guo-peng LI Zhe HUANG Ai-jun |
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| Affiliation: | 1. School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha 410114, Hunan, China;2. International College of Engineering, Changsha University of Science and Technology, Changsha 410114, Hunan, China;3. Transportation Quality Supervision Department of Inner Mongolia, Hohhot 010050, Inner Mongolia, China;4. Shenzhen Municipal Engineering Corp, Shenzhen 518034, Guangdong, China |
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| Abstract: | In order to reveal the modulus of graded aggregate's structural service condition correlation, this paper studied the modulus characteristics of graded aggregate through dynamic triaxial test and full-scale test. The dynamic resilient modulus of graded aggregate under different service conditions were studied using the dynamic triaxial test by controlling moisture content, compactness, confining pressure, and deviator stress. The results show that the resilient modulus of dynamic triaxial test decreases with the increase of moisture content and increases with the increase of compactness, confining pressure, and deviator stress. The equivalent modulus and structural modulus of the top layer of graded aggregate was measured using layered paving and excavation tests, during which bearing plate testing and PFWD were adopted. The test results of layered paving show that the value of equivalent modulus and structural modulus increase with the increase of the overlay's thickness, the increasing rate decreases with the increase of overlay's thickness. The equivalent modulus of graded aggregate top layer increases with the top layer equivalent modulus of the bearing layer, the increasing rate decreases gradually. The test results of excavation show that the equivalent modulus of graded aggregate top layer climbs with and then declines on account of the upper graded aggregate layers. The peak value of appeared when the excavation depth is equal to 20 cm. The value decreases with the increase of the excavation depth, and the rate of value reduction decreases gradually. According to the test results of laboratory and field test, the structural modulus of field test is higher than the laboratory test results. Using triaxial modulus test results in pavement structure design may underestimate the bearing capacity of graded aggregate, which results in large design deviation. Excavation method consider the influence of the weight of the bearing layer and the covering structure layer weight and friction force, which correlate with actual service condition better. |
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| Keywords: | road engineering graded aggregate layered paving excavation modulus |
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