返回
类型 应用研究 预答辩日期 2017-09-30
开始(开题)日期 2014-09-03 论文结束日期 2017-06-02
地点 道桥实验室二楼会议室 论文选题来源 企、事业单位委托项目    论文字数 10.7 (万字)
题目 黑棉土路基处治与路面结构一体化技术研究
主题词 黑棉土地基,路基开裂,处治技术,附加应力,适应性
摘要 为了分析黑棉土的物理化学和强度特性,进行了颗粒分析、矿物组成分析、液塑限、自由膨胀率、阳离子交换量、击实和CBR试验。试验表明,黑棉土黏粒含量高,液限和塑性指数高,自由膨胀率大,蒙脱石含量高,交换性阳离子数量大,CBR值小。蒙脱石含量高,更易吸附较多的可交换阳离子,导致了黑棉土的强膨胀性。 基于饱和-非饱和土固结耦合理论,分析了黑棉土地区路堤的初始开裂行为。使用ABAQUS建立了黑棉土地区典型路堤断面有限元模型,模拟了路堤基顶张拉应力峰值和峰值位置的改变。模拟表明,路堤基顶张拉应力峰值随着蒸发的进行逐渐朝路肩移动。蒸发强度越大,地表蒸发时路堤顶面张拉应力峰值增大越快,其位置越靠近路肩。厚层黑棉土有助于路堤顶面张拉应力峰值快速到达其抗拉强度阈值。路堤越高,路堤顶面张拉应力峰值越小,其位置越远离路肩。随着黑棉土地基处治深度的增加,路堤最大主应力峰值、开裂范围和深度逐渐减小,不过,不同黑棉土埋深和路堤高度下,地基处治深度对路堤初始开裂的影响差异较大。因此,薄层黑棉土上修筑较高路堤可以减少路堤裂缝的形成,不同路堤高度和黑棉土埋深宜采用不同的地基处治深度。 针对黑棉土的工程特性,提出了黑棉土路堤的化学和物理处治方法。采用液塑限、CBR等试验,分析了石灰和火山灰对黑棉土工程性质的影响;通过数值模拟分析了不同物理处治技术路堤的变形特性。结果表明,石灰和石灰火山灰复配极大地改善了黑棉土的工程特性,6%的石灰或3%的石灰和15%的火山灰复配处治的黑棉土即可满足路基设计规范对路堤填料的要求。黑棉土包边处治时,路堤变形随着地基处治深度和包边处治厚度的增加而减小,基于弯沉等效的黑棉土路基刚度补偿设计可用于确定其顶封层的厚度。黑棉土地基土工膜处治时,处治深度宜通过大气影响深度确定。试验路监测结果验证了不同黑棉土路堤物理处治技术的有效性。 基于灰色关联决策分析,分析了不同路面结构对黑棉土处治路堤的适应性。使用ABAQUS建立了路堤路面有限元模型,模拟了黑棉土处治路堤上铺筑沥青路面结构时的路表变形及路面附加应力。模拟表面,下基层模量和厚度的变化对路表变形的影响甚微,而对下基层层底、控制层层底和面层顶面的附加应力影响较大。黑棉土处治路堤上铺筑夹层结构时,下基层的模量和厚度宜适当增大,铺筑半刚性基层结构时,采用常规模量和设计厚度即可。设置抗疲劳层的级配碎石夹层路面结构较半刚性基层结构更能适应黑棉土处治路堤的不均匀变形。
英文题目 Study on Integrative Technology of Treatment of Subgrade on Black Cotton Soil and Pavement Structure
英文主题词 black cotton soil foundation, subgrade crack, treatment technology, additional stress, adaptabilit
英文摘要 In order to analyze the physical and chemical properties and strength characteristic of the black cotton soil (BCS), the grain size analysis, mineral composition analysis, Atterberg limits, free swelling ratio tests, cation exchange capacity, the standard Proctor test and California bearing ratio (CBR) tests were conducted. The test results indicate that BCS is high in clay content, liquid limit, plasticity index, free swelling ratio, montmorillonite content, as well as the number of exchangeable cations, and low in CBR value. The high montmorillonite content is easy to absorb more exchangeable cations, which leads to the higher expansiveness of BCS. Based on the coupled consolidation theory for saturated-unsaturated soils,the initial cracking behavior of highway embankment in the regions of BCS is analyzed. The finite element model (FEM) of a typical highway embankment section in the regions of BCS is built by ABAQUS to simulate the change of peaks of tensile stress and its location on the embankment top. The simulation results indicate that the peaks of tensile stress on the embankment top gradually move towards the shoulder following the evaporation duration. When the evaporation intensity is larger, the peak of tensile stress on the embankment top increases at a faster rate following the soil surface evaporation, and its location is closer to the shoulder. The thicker BCS layer helps the peaks of tensile stress to reach the critical tensile stress fast. The higher the embankment, the smaller peak of tensile stress occurred on the embankment top, and its location is more far away from the shoulder. The peak of tensile stress、crack extent and depth gradually decrease following the increase in the treatment deepness of BCS foundation, but the influence of treatment deepness on initial crack of embankment has large differences under different BCS layer thickness and embankment height. Therefore, the higher embankment constructed on the thinner BCS layer can decrease the crack generation within the highway embankment, the different foundation treatment deepness should be adopted under different BCS layer thickness and embankment height. The chemical and physical treatment technology of BCS embankment is proposed for its engineering characteristic. The influence of lime and volcanic ash on the engineering characteristic of BCS is analyzed by Atterberg limits, CBR tests and more. The deformation characteristics of highway embankment under different physical treatment technology are analyzed by numerical simulation. The results show that the lime and the combination of lime and VA significantly enhanced the engineering characteristic of BCS. Based on the code for design of highway subgrades, the BCS can be used as the highway embankment filling at the addition of 6% lime or 3% lime and 15% volcanic ash. When the side slopes of BCS embankment are enveloped with nonexpansive clay, the deformation of highway embankment decrease following the increase in the treatment deepness of BCS foundation and the width of nonexpansive clay, a design method for increasing the stiffness of BCS subgrade can be used to determine its top sealing thickness based on deflection equivalence. When the BCS foundation is treated with the geomembrane, the treatment deepness can be determined by the active zone of BCS. The surveillance of test road verifies the effectiveness of different physical treatment technology of BCS embankment. Based on grey incidence decision-making method,adaptability of different pavement structures versus treated BCS embankment is analyzed.FEM of subgrade and pavement is built by ABAQUS to simulate the deformation and additional stress of pavement structure constructed on treated BCS embankment. The simulation results indicate that the influence of change in the thickness and modulus of the subbase on deformation of the pavement surface is small, but it significantly influences the additional stress on the bottom of subbase and control layer, as well as the top of surface course. When the sandwich structure is constructed on the treated BCS embankment, the thickness and modulus of the subbase should be increased appropriately, but when the semi-rigid base pavement structure is constructed, the conventional modulus and design thickness of subbase can be adopted. The sandwich structure of unbound graded aggregate paved fatigue-resistant layer is more adaptable to differential deformation of treated BCS embankment, compared to the semi-rigid base pavement structure.
学术讨论
主办单位时间地点报告人报告主题
交通学院 2013-10-12 道桥试验室二楼会议室 李昶 东部非洲黑棉土地区公路路基路面设计与施工技术研究
交通学院 2015-08-23 道桥试验室二楼会议室 李凌林 沥青路面长大纵坡段车辙性能研究
交通学院 2016-12-06 道桥试验室二楼会议室 唐皓 东非黑棉土的膨胀特性及处治技术研究
交通学院 2016-12-26 道桥试验室二楼会议室 郭辉 基于多参数描述的沥青混合料构成研究
交通学院 2016-09-15 道桥试验室二楼会议室 程永振 Field and Numerical investigation of soil-atmosphere interaction at Nairobi, Kenya
交通学院 2014-08-29 道桥试验室二楼会议室 程永振 基于增湿变形的黑棉土路基处治技术与路面结构优化研究
交通学院 2015-08-28 道桥试验室二楼会议室 程永振 黑棉土路基处治不路面结构一体化技术研究
交通学院 2015-12-15 道桥试验室二楼会议室 程永振 肯尼亚内罗毕绕城公路南环线工程黑棉土路基路面试验段方案
     
学术会议
会议名称时间地点本人报告本人报告题目
第四届中欧功能性路面设计研讨会 2016-06-29 荷兰代尔夫特 Adaptability of pavement structures on expansive soil embankment with differential deformations
第四届交通运输工程领域博士生论坛 2015-05-31 哈尔滨 Swell and shrink predictions of expansive soil
成都理工大学黄润秋教授学术报告会 2015-04-10 南京
2015年校庆研究生学术报告会 2015-5-10 南京
     
代表作
论文名称
Field and numerical investigation of soil-atmosphere interaction at Nairobi, Kenya
Soil-atmosphere interaction as triggering factors of openings between embankment and pavement
Numerical analysis of crack generation within embankment built on expansive soil foundation
Adaptability of Pavement Structures on Expansive Soil Embankment with Differential Deformations
 
答辩委员会组成信息
姓名职称导师类别工作单位是否主席备注
赵永利 正高 教授 博导 东南大学交通学院
赵尘 正高 教授 博导 南京林业大学
许涛 正高 教授 博导 南京林业大学
章定文 正高 教授 博导 东南大学交通学院
马涛 正高 教授 博导 东南大学交通学院
      
答辩秘书信息
姓名职称工作单位备注
廖公云 副高 副教授 东南大学交通学院