| 重复荷载作用下粉性路基土累积塑性变形研究 |
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| 引用本文： | 董城,冷伍明,李志勇,邹静蓉.重复荷载作用下粉性路基土累积塑性变形研究[J].岩土力学,2014,35(12):3437-3442. |
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| 作者姓名： | 董城 冷伍明 李志勇 邹静蓉 |
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| 作者单位： | 1.中南大学 土木工程学院，长沙 410075；2.湖南省交通科学研究院，长沙 410015；3.中南林业科技大学 土木工程与力学学院，长沙 410004 |
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| 基金项目： | 国家自然科学基金重点项目（No. U1361204）；交通部西部交通建设科技项目（No. 2011 318 785 760，No.2009 318 785 104）。 |
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| 摘 要： | 为研究不同含水率、压实度和应力水平下路基压实粉性路基土累积塑性变形影响因素与变化规律,开展了系列动三轴试验。根据累积塑性应变随加载次数的变化规律,获得了不同含水率、压实度下粉土的临界动应力。研究表明,粉性路基土临界动应力随压实度的提高而增大,随含水率的增大而减小。为避免路面结构的破坏,路基土应力状态应控制在临界应力界限范围内。鉴于此,针对路基土临界应力范围内的试验数据,建立了路基土累积塑性变形预估模型。该模型考虑了应力和加载次数的影响。回归分析表明,该模型具有较高的决定系数,即模型具有较高的合理性与可靠性。模型的建立为基于力学经验法的路基累积塑性变形计算提供了参数。最后以典型水泥混凝土路面为例,获得了不同轴载、轴型作用下粉土路基累积塑性变形,为进一步研究路基累积塑性变形对路面结构的影响提供了思路。
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| 关 键 词： | 粉性路基土 动三轴试验 累积塑性变形 临界动应力 预估模型 路基工作区 分层总和法 |
| 收稿时间： | 2013-08-02 |
Study of accumulative plastic deformation of silty subgrade soil under repeated loading |
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| DONG Cheng,LENG Wu-ming,LI Zhi-yong,ZOU Jing-rong.Study of accumulative plastic deformation of silty subgrade soil under repeated loading[J].Rock and Soil Mechanics,2014,35(12):3437-3442. |
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| Authors: | DONG Cheng LENG Wu-ming LI Zhi-yong ZOU Jing-rong |
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| Institution: | 1. School of Civil Engineering, Central South University, Changsha 410075, China; 2. Hunan Communications Research Institute, Changsha 410015, China; 3. College of Civil Engineering and Mechanics, Central South University of Forestry and Technology, Changsha 410004, China |
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| Abstract: | For the sake of investigating the accumulative plastic deformation and its influencing factors of silt with different compaction degrees, moisture contents and stress levels under the repeated loading, a series of dynamic triaxial tests is carried out. According to the relation curves between accumulative plastic strain and loading number，the critical dynamic stresses of silt are obtained. The experimental results demonstrate that the critical dynamic stress values of silt rise with the increase of compaction degree ,and in reverse of moisture content.In order to avoid damage of the pavement structure, the stress state of subgrade should be controlled within the boundaries of the critical dynamic stress. In view of this, the test data within the critical dynamic stress is analyzed; and a new accumulative plastic deformation prediction model of subgrade soil is put forward. The model takes into account the influencing factors of stress and loading number. Through regression analysis, a consistency between the predictive results and the experimental data is obtained. It is shown that the model is accurate and credible. The proposed mode can provide parameters for the subgrade accumulative plastic deformation calculation based on mechanics empirical method. For typical cement concrete pavement structure, the accumulative plastic deformation of silty subgrade under different axial loads and axle configurations are obtained; and it can provide ideas for further evaluation of the effect of accumulative plastic deformation on pavement structure. |
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| Keywords: | silty subgrade soil dynamic triaxial test accumulative plastic deformation critical dynamic stress prediction model subgrade workspace layerwise summation method |
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