水泥混凝土路面极限承载力研究
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硕士学位论文
图4.10混凝土板最大弯拉应力..
图4.1l混凝土板综合应力……..
图4.12混凝土板最大竖向位移,,
67
vIIl
水泥混凝士路面极限承载力研究
附表索引
表2.1 永连公路车辆流量统计表……………………………………………..
表2.2 永连公路超限车辆单轴轴载统计表………………………………….
1Il
Key Words:Cement concrete pavements;Heavy—load;Ultimate bearing capacity;
Design method of pavements;Cavity beneath road slabs
水泥混凝士路面极限承载力研究
插图索引
图1.1 水泥混凝土路面典型损坏类型………………………………………………..1 图2.1 永连公路调查路段超限车辆单轴轴载分布…………………………………12 图2.2永连公路调查路段超限车辆双轴轴载分布…………………………………12 图2.3轮胎接地面积的测量…………………………………………………………l 3 图2.4轮胎接地形状印痕……………………………………………………………14 图2.5双层弹性地基体系参数取值…………………………………………………17 图2.6弯沉等效示意图………………………………………………………………17 图2.7规范公式与式(2.9)、 (2.1 1)关于n的计算结果对比………………19 图2.8 刚性路面板承载示意图………………………………………………………21 图2.9车辆荷载作用图式……………………………………………………………24 图2.10车辆荷载位置图………………………………………………………………24 图2,11轮胎接地压力与轴载的关系…………………………………………………25 图2.12 PCAD计算程序有限元分析网格划分示意图………………………………27 图2.13水泥混凝土路面荷载应力和综合应力………………………………………29 图2.14混凝土弯拉强度对极限承载力的影响………………………………………31 图2.1 5混凝土板厚对极限承载力的影响…………………,.………………………,31 图2.16基层顶面当量回弹模量对极限承载力的影响………………………………31 图2.17温度梯度对极限承载力的影响………………………………………………32 图3.1 晴天水泥混凝土面层的温度日变化曲线……………………………………38 图3.2晴天水泥混凝土面层的温度梯度日变化曲线………………………………38 图3.3温度梯度频率曲线……………………………………………………………43 图3.4典型重载混凝土路面结构……………………………………………………47 图3.5混凝土路面设计流程图………………………………………………………49 图4.1 板底脱空引起的横向开裂……………………………………………………53 图4.2混凝土路面结构有限元分析模型……………………………………………55 图4.3 20节点六面体等参单元……………………………………………………56 图4,4三维路面结构网格划分示意图………………………………………………6l 图4.5车辆荷载位置图………………………………………………………………62 图4.6混凝土板纵向应力云图(纵缝边缘中部,P=200kN)……………………63 图4.7 路面结构模型竖向位移云图(纵缝边缘中部,P=200kN)………………64 图4,8混凝土板主应力sl云图(板角,P=300kN)……………………………64 图4.9混凝土板竖向位移云图(板角,P=300kN)………………………………64
analyzed with elasticity theory,based on actually applied pattern of heavy loading, analysis method of ultimate bearing capacity of pavement structures was proposed, and the factors affecting ultimate bearing capacity were analyzed also,which provided a theoretical basis for the restriction of alex load.Again,the probabilities of vehicle axle load and temperature gradient were studied;the design method of cement concrete pavements considering ultimate bearing capacity was proposed,and the typical pavement structures meeting the levels of axle load limits were developed also Finally,in response to the cavities beneath road slabs,3D finite element analyses of pavment structures were conducted,the impacts on bearing capacity and life of
湖南大学 硕士学位论文 水泥混凝土路面极限承载力研究 姓名:孔铭 申请学位级别:硕士 专业:道路与铁道工程 指导教师:黄立葵
20060522
硕士学位论文
摘要
近年来,我国公路交通运输不断发展,公路超载运输现象也日益普遍和严重。 水泥混凝土路面作为高等级公路的主要形式之一,很多在使用初期就发生了严重 的结构损坏,路面的使用寿命大大缩短,严重影响了公路的通行能力、行车安全 和投资效益。当路面板荷载应力与温度应力的组合处于不利状态时,过大轴载的 一次作用就可能造成路面结构的破坏,路面结构的抗疲劳性则无从谈起。世界各 国水泥混凝土路面结构设计方法中尚未引入极限承载力的分析方法。因此,根据 公路实际的交通组成和温度状况,研究水泥混凝土路面结构极限状态的分析和设 计方法成为迫切需要解决的问题。
In this paper,the traffic surveys and analysis of typical heavy—load road were
performed firstly;Also the characteristics of traffic,load and distribution of axle load were studied.The deficiencies in the calculation method of surface equivalent modulus of foundation in present specification of cement concrete pavements design for highway were analyzed.Based on the elastic multi—layer theory and principles of
表2.3 永连公路超限车辆双轴轴载统计表………………………………….
表2.4 车辆参数汇总表……………………………………………………….
¨¨¨n
表2.5 不同路面结构当量回弹模量换算结果比较………………………….
表2.6 不同计算方法下双层结构基层顶面当量回弹模量值比较………….
表2.7 路面结构与材料性质………………………………………………….
关键词:水泥混凝土路面;重荷载;极限承载力;设计方法:板底脱空
II
奎鎏堡墼圭塑耍墼堡童墼童墼圣
Abstract
With the development of highway in our country,road transportation overloading becomes widespread and serious.As one of the main structures of highway,many of cement concrete pavements are distressed seriously in the early of life,and the road life is significantly shortened;also the road capacity,traffic safety and investment returns are seriously affected.When the load stress and temperature stress of road slabs combine in a disadvantaged state,pavment structures may be distressed when a large axle load loading one time,the fatigue of pavment structures becomes insignificant.Procedures to analyze ultimate bearing capacity of pavement structures have not been included in existing specifications for design of cement concrete pavements in the world.Therefore,studies on analysis and design method of cement concrete pavements in ultimate states based on actual composition of road traffic and temperature conditions become more important.
pavements caused by cavities were analyzed,the reasons of early distresses were
revealed;Also,in the aspects of pavement materials and structures,the measures and methods to prevent cavities were explored.
displacement equivalence,and a great amount of computing data,a calculation method was established.Then,mechanical responses of pavement structures were
本文首先从典型重载交通道路的交通调查与分析入手,研究了重荷载交通道 路的交通量、轴载分布及荷载特征,针对现行设计规范中关于基层顶面当量回弹 模量值计算公式存在的不足,利用弹性层状体系理论,按照弯沉等效原则,通过 大量的计算分析,回归出了精度较高、适用范围更广的基层顶面当量回弹模量计 算公式。其次,根据实测荷载作用面积和计算轮胎接地压力,计算了重荷载作用 下水泥混凝土路面结构的力学响应,提出了分析混凝土路面极限承载力的方法, 并分析的概率特征,提出了考虑极限承载力的混凝土路面设计方法,并拟 定了满足各级极限轴载的典型混凝土路面结构形式。最后,针对混凝土路面板板 底脱空现象,对路面结构建立三维有限元模型,通过大量的有限元计算,分析了 板底脱空对路面板承载力及使用寿命的影响,揭示了路面发生早期损坏的根本原 因,并从路面材料和结构设计方面探讨了防止路面板脱空的措施和方法。
硕士学位论文
图4.10混凝土板最大弯拉应力..
图4.1l混凝土板综合应力……..
图4.12混凝土板最大竖向位移,,
67
vIIl
水泥混凝士路面极限承载力研究
附表索引
表2.1 永连公路车辆流量统计表……………………………………………..
表2.2 永连公路超限车辆单轴轴载统计表………………………………….
1Il
Key Words:Cement concrete pavements;Heavy—load;Ultimate bearing capacity;
Design method of pavements;Cavity beneath road slabs
水泥混凝士路面极限承载力研究
插图索引
图1.1 水泥混凝土路面典型损坏类型………………………………………………..1 图2.1 永连公路调查路段超限车辆单轴轴载分布…………………………………12 图2.2永连公路调查路段超限车辆双轴轴载分布…………………………………12 图2.3轮胎接地面积的测量…………………………………………………………l 3 图2.4轮胎接地形状印痕……………………………………………………………14 图2.5双层弹性地基体系参数取值…………………………………………………17 图2.6弯沉等效示意图………………………………………………………………17 图2.7规范公式与式(2.9)、 (2.1 1)关于n的计算结果对比………………19 图2.8 刚性路面板承载示意图………………………………………………………21 图2.9车辆荷载作用图式……………………………………………………………24 图2.10车辆荷载位置图………………………………………………………………24 图2,11轮胎接地压力与轴载的关系…………………………………………………25 图2.12 PCAD计算程序有限元分析网格划分示意图………………………………27 图2.13水泥混凝土路面荷载应力和综合应力………………………………………29 图2.14混凝土弯拉强度对极限承载力的影响………………………………………31 图2.1 5混凝土板厚对极限承载力的影响…………………,.………………………,31 图2.16基层顶面当量回弹模量对极限承载力的影响………………………………31 图2.17温度梯度对极限承载力的影响………………………………………………32 图3.1 晴天水泥混凝土面层的温度日变化曲线……………………………………38 图3.2晴天水泥混凝土面层的温度梯度日变化曲线………………………………38 图3.3温度梯度频率曲线……………………………………………………………43 图3.4典型重载混凝土路面结构……………………………………………………47 图3.5混凝土路面设计流程图………………………………………………………49 图4.1 板底脱空引起的横向开裂……………………………………………………53 图4.2混凝土路面结构有限元分析模型……………………………………………55 图4.3 20节点六面体等参单元……………………………………………………56 图4,4三维路面结构网格划分示意图………………………………………………6l 图4.5车辆荷载位置图………………………………………………………………62 图4.6混凝土板纵向应力云图(纵缝边缘中部,P=200kN)……………………63 图4.7 路面结构模型竖向位移云图(纵缝边缘中部,P=200kN)………………64 图4,8混凝土板主应力sl云图(板角,P=300kN)……………………………64 图4.9混凝土板竖向位移云图(板角,P=300kN)………………………………64
analyzed with elasticity theory,based on actually applied pattern of heavy loading, analysis method of ultimate bearing capacity of pavement structures was proposed, and the factors affecting ultimate bearing capacity were analyzed also,which provided a theoretical basis for the restriction of alex load.Again,the probabilities of vehicle axle load and temperature gradient were studied;the design method of cement concrete pavements considering ultimate bearing capacity was proposed,and the typical pavement structures meeting the levels of axle load limits were developed also Finally,in response to the cavities beneath road slabs,3D finite element analyses of pavment structures were conducted,the impacts on bearing capacity and life of
湖南大学 硕士学位论文 水泥混凝土路面极限承载力研究 姓名:孔铭 申请学位级别:硕士 专业:道路与铁道工程 指导教师:黄立葵
20060522
硕士学位论文
摘要
近年来,我国公路交通运输不断发展,公路超载运输现象也日益普遍和严重。 水泥混凝土路面作为高等级公路的主要形式之一,很多在使用初期就发生了严重 的结构损坏,路面的使用寿命大大缩短,严重影响了公路的通行能力、行车安全 和投资效益。当路面板荷载应力与温度应力的组合处于不利状态时,过大轴载的 一次作用就可能造成路面结构的破坏,路面结构的抗疲劳性则无从谈起。世界各 国水泥混凝土路面结构设计方法中尚未引入极限承载力的分析方法。因此,根据 公路实际的交通组成和温度状况,研究水泥混凝土路面结构极限状态的分析和设 计方法成为迫切需要解决的问题。
In this paper,the traffic surveys and analysis of typical heavy—load road were
performed firstly;Also the characteristics of traffic,load and distribution of axle load were studied.The deficiencies in the calculation method of surface equivalent modulus of foundation in present specification of cement concrete pavements design for highway were analyzed.Based on the elastic multi—layer theory and principles of
表2.3 永连公路超限车辆双轴轴载统计表………………………………….
表2.4 车辆参数汇总表……………………………………………………….
¨¨¨n
表2.5 不同路面结构当量回弹模量换算结果比较………………………….
表2.6 不同计算方法下双层结构基层顶面当量回弹模量值比较………….
表2.7 路面结构与材料性质………………………………………………….
关键词:水泥混凝土路面;重荷载;极限承载力;设计方法:板底脱空
II
奎鎏堡墼圭塑耍墼堡童墼童墼圣
Abstract
With the development of highway in our country,road transportation overloading becomes widespread and serious.As one of the main structures of highway,many of cement concrete pavements are distressed seriously in the early of life,and the road life is significantly shortened;also the road capacity,traffic safety and investment returns are seriously affected.When the load stress and temperature stress of road slabs combine in a disadvantaged state,pavment structures may be distressed when a large axle load loading one time,the fatigue of pavment structures becomes insignificant.Procedures to analyze ultimate bearing capacity of pavement structures have not been included in existing specifications for design of cement concrete pavements in the world.Therefore,studies on analysis and design method of cement concrete pavements in ultimate states based on actual composition of road traffic and temperature conditions become more important.
pavements caused by cavities were analyzed,the reasons of early distresses were
revealed;Also,in the aspects of pavement materials and structures,the measures and methods to prevent cavities were explored.
displacement equivalence,and a great amount of computing data,a calculation method was established.Then,mechanical responses of pavement structures were
本文首先从典型重载交通道路的交通调查与分析入手,研究了重荷载交通道 路的交通量、轴载分布及荷载特征,针对现行设计规范中关于基层顶面当量回弹 模量值计算公式存在的不足,利用弹性层状体系理论,按照弯沉等效原则,通过 大量的计算分析,回归出了精度较高、适用范围更广的基层顶面当量回弹模量计 算公式。其次,根据实测荷载作用面积和计算轮胎接地压力,计算了重荷载作用 下水泥混凝土路面结构的力学响应,提出了分析混凝土路面极限承载力的方法, 并分析的概率特征,提出了考虑极限承载力的混凝土路面设计方法,并拟 定了满足各级极限轴载的典型混凝土路面结构形式。最后,针对混凝土路面板板 底脱空现象,对路面结构建立三维有限元模型,通过大量的有限元计算,分析了 板底脱空对路面板承载力及使用寿命的影响,揭示了路面发生早期损坏的根本原 因,并从路面材料和结构设计方面探讨了防止路面板脱空的措施和方法。