检索结果-南通市图书馆

Investigation of differential movement at railroad bridge approaches through geotechnical instrumentation

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第11期13卷 814-824页

作者： Debakanta MISHRA erol tutumluer Timothy D.STARK James P.HYSLIP Steven M.CHRISMER Michael TOMAS Department of Civil and Environmental Engineering University of Illinois at Urbana-ChampaignUrbanaUSA HyGround Engineering LLCWilliamsburgMassachusettsUSA National Railroad Passenger Corporation(Amtrak) PhiladelphiaUSA

Railway transitions experience differential movements due to differences in track system stiffness,track damping characteristics,foundation type,ballast settlement from fouling and/or degradation,as well as fill and subgrade *** differential movement is especially problematic for high speed rail infrastructure as the 'bump' at the transition is accentuated at high *** of different factors contributing towards this differential movement,as well as development of design and maintenance strategies to mitigate the problem is imperative for the safe and economical operation of both freight and passenger rail *** paper presents the research framework and initial instrumentation details from an ongoing research effort at the University of Illinois at *** bridge approaches experiencing recurrent geometry problems were instrumented using multidepth deflectometers(MDDs) and strain gages to identify different factors contributing to the development of differential movements.

关键词： Track transition Differential movement Bridge approach Multidepth deflectometer(MDD) Bump at the end of the bridge Strain gage

振动荷载下级配碎石颗粒运动及其能量特征试验研究

在线全文

学校读者我要写书评

暂无评论

土木工程学报 2023年第3期56卷 78-89页

作者：肖源杰王萌于群丁华文俊姜钰 tutumluer erol 中南大学土木工程学院湖南长沙410075 中南大学重载铁路工程结构教育部重点实验室湖南长沙410075 中铁第四勘察设计院集团有限公司湖北武汉430063 伊利诺伊大学香槟分校美国香槟61801

大空隙级配碎石因其良好的透(排)水性能逐渐用作“海绵城市”路面结构的基层填料,但振动荷载作用下填料颗粒在重新排列过程中的运动姿态变化以及能量状态空间分布规律仍不明确。文章基于颗粒堆积理论设计了不同级配的碎石填料,开展不同... 详细信息

大空隙级配碎石因其良好的透(排)水性能逐渐用作“海绵城市”路面结构的基层填料,但振动荷载作用下填料颗粒在重新排列过程中的运动姿态变化以及能量状态空间分布规律仍不明确。文章基于颗粒堆积理论设计了不同级配的碎石填料,开展不同激振参数组合下的室内新型平板振动压实试验,在试样内部不同位置处放置新型智能颗粒传感器(SmartRock)实时监测压实过程中颗粒的运动姿态变化,由颗粒加速度响应分析填料内部运动能量的时空演变规律,进而提出基于颗粒运动和能量分布的填料压实质量评价新指标。研究结果表明,级配碎石填料振动压实过程可明显分为两个不同阶段:第一阶段大部分能量耗散于碎石颗粒的竖向运动及空隙的压缩,占主导的颗粒竖向运动未形成致密的骨架结构;第二阶段颗粒主要发生水平面内的平动以及竖直面内的滚动,颗粒的长轴取向逐渐趋近于“平躺”状态,大部分能量耗散于颗粒间空隙的填充,颗粒逐渐互相紧密咬合嵌挤并形成稳定的骨架结构。试样中上部颗粒的运动指标可较好地评判压实状态,当颗粒水平向运动能量从逐渐增大过渡到逐渐减小至几乎没有任何能量分布但竖向能量分布突增时,表明试样已达到较优的压实状态,新的颗粒运动和能量指标可为连续压实质量智能评价和调控技术研究提供有益的理论依据和研究基础。

关键词：振动压实透水性基床级配碎石颗粒运动振动能量压实评价智能颗粒传感器

Probabilistic model and analysis of coupled train-ballasted track-subgrade system with uncertain structural parameters

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2021年第7期28卷 2238-2256页

作者： MAO Jian-feng XIAO Yuan-jie YU Zhi-wu erol tutumluer ZHU Zhi-hui School of Civil Engineering Central South UniversityChangsha 410075China National Engineering Laboratory for High-Speed Railway Construction Changsha 410075China Key Laboratory of Engineering Structures of Heavy Haul Railway of Ministry of Education Central South UniversityChangsha 410075China Department of Civil and Environmental Engineering University of Illinois at Urbana-ChampaignUrbanaIL 61801United States

Random dynamic responses caused by the uncertainty of structural parameters of the coupled train-ballasted track-subgrade system under train loading can pose safety concerns to the train *** paper introduced a computational model for analyzing probabilistic dynamic responses of three-dimensional(3D)coupled train-ballasted track-subgrade system(TBTSS),where the coupling effects of uncertain rail irregularities,stiffness and damping properties of ballast and subgrade layers were simultaneously *** number theoretical method(NTM)was employed to design discrete points for the multi-dimensional stochastic *** time-histories of stochastic dynamic vibrations of the TBSS with systematically uncertain structural parameters were calculated accurately and efficiently by employing the probability density evolution method(PDEM).The model-predicted results were consistent with those by the Monte Carlo simulation method.A sensitivity study was performed to assess the relative importance of those uncertain structural parameters,based on which a case study was presented to explore the stochastic probability evolution mechanism of such train-ballasted track-subgrade system.

关键词： coupled train-ballast-subgrade system structural parameter uncertainty stochastic dynamic analysis probability density evolution method wheel-rail interaction

基于离散元-有限差分耦合的轨枕垫对有砟道床横向阻力的影响机制

在线全文

学校读者我要写书评

暂无评论

中南大学学报（自然科学版） 2024年第2期55卷 457-472页

作者：谭攀肖源杰姜钰王萌王小明张冲冲 tutumluer erol 中南大学土木工程学院湖南长沙410075 重载铁路工程结构教育部重点实验室(中南大学) 湖南长沙410075 伊利诺伊大学香槟分校香槟61801美国

轨枕垫(USP)因其良好的减震性能已广泛应用于铁路轨道结构,现有研究大多集中于USP对轨道结构刚度和振动响应的影响,但对有砟道床横向阻力影响的研究很少。为深入分析USP对道床横向阻力的影响并揭示其作用机理,建立轨枕-USP-有砟道床-路... 详细信息

轨枕垫(USP)因其良好的减震性能已广泛应用于铁路轨道结构,现有研究大多集中于USP对轨道结构刚度和振动响应的影响,但对有砟道床横向阻力影响的研究很少。为深入分析USP对道床横向阻力的影响并揭示其作用机理,建立轨枕-USP-有砟道床-路基三维系统的精细化离散元-有限差分(DEM-FDM)耦合数值模型,采用典型重载铁路有砟道床横向阻力现场实测结果对模型进行标定和验证,进而模拟分析不同工况组合下USP对轨枕不同位置处(枕底、枕侧和枕端)的横向阻力、道砟颗粒运动和粒间接触力等宏微观指标的影响机制。研究结果表明:在相同的轨枕横向位移下,相较于无USP的轨枕,带USP的轨枕其枕底道砟颗粒运动范围更大,横向阻力也更大,且横向阻力增加部分主要来源于枕底USP的不平整性;USP刚度越大,道床横向阻力也越大;采用USP可增加枕底的横向剪应力和最大法向接触力,且两者数值均随USP刚度的增大而增大。

关键词：铁路轨道有砟道床道砟轨枕垫横向阻力离散元-有限差分耦合

在线全文

学校读者我要写书评

暂无评论

建筑拆除废弃物再生骨料颗粒破碎与压缩特性

Journal of Central South University 2023年第10期30卷 3499-3516页

作者：孔坤锋陈锋肖源杰李昀博姜钰王萌 tutumluer erol 陈宇亮李志勇 Railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China School of Civil Engineering Central South UniversityChangsha 410075China Key Laboratory of Engineering Structures of Heavy-haul Railway of Ministry of Education(Central South University) Changsha 410075China Department of Civil&Environmental Engineering University of Illinois at Urbana-ChampaignUrbanaIL 61801U.S.A. Hunan Communications Research Institute Corporation Limited Changsha 410015China

使用回收的建筑拆除废弃物作为无黏结骨料是路面基层/底基层施工的资源节约型、经济型和生态友好型替代方法之一。单个粗集料颗粒的细观强度和压碎特性会对此类再生无黏结集料的宏观强度和变形行为产生重大影响。本文通过单颗粒压碎试... 详细信息

使用回收的建筑拆除废弃物作为无黏结骨料是路面基层/底基层施工的资源节约型、经济型和生态友好型替代方法之一。单个粗集料颗粒的细观强度和压碎特性会对此类再生无黏结集料的宏观强度和变形行为产生重大影响。本文通过单颗粒压碎试验和侧限压缩试验系统地研究了不同粒径和成分的再生骨料的压碎强度和压缩变形特性。试验结果表明,单颗粒破碎强度具有显著的尺寸效应,对于同种类型的再生骨料,破碎应力峰值随颗粒尺寸的增大而减小。此外,采用双曲线函数可以很好地描述侧限压缩过程的应力-应变关系。在相同的垂直应力水平下,随着粒径的增大,垂直应变和屈服应力值分别逐渐增大和减小。最后,采用颗粒破碎指标B_(r)量化了不同垂直应力水平下各粒度范围的颗粒破碎情况。根据破碎指标Br的预测公式的极限值,可得出各粒度范围的极限破碎状态。

关键词：建筑拆除废弃物再生骨料颗粒破碎永久变形单颗粒破碎试验侧限压缩试验