摘要
研究目的:目前,关于纵连板式无砟轨道可靠度的研究均基于假设的经验分布模型。为了探究依据实测数据统计分析纵连板式无砟轨道结构性能和状态的随机分布特征,本文依托肖家河特大桥工程实例,对华中地区简支梁桥上的轨道板、底座板及宽窄接缝强度大小和开裂情况进行现场测量和统计。研究结论:(1)现场无砟轨道结构强度大小近似呈高斯分布,其中,轨道板强度概率密度函数服从均值为54.56 MPa、方差为0.98的正态分布,底座板强度概率密度函数近似服从均值为36.58 MPa、方差为2.15的正态分布,相比现浇混凝土底座板,预制轨道板强度更接近于理论值,且离散性相对较小;(2)宽窄接缝强度概率密度函数近似服从均值为45.44 MPa、方差为1.52的正态分布,现场宽窄接缝的强度难以达到理论设计强度,为防止后期宽窄接缝开裂和破损,建议改进宽窄接缝施工技术或增加宽窄接缝混凝土标号;(3)曲线梁上,底座板超高侧裂缝宽度大小概率密度函数近似服从均值为0.11 mm、方差为0.07的正态分布,非超高侧裂缝宽度大小近似服从均值为0.07 mm、方差为0.04的正态分布,底座板超高侧裂缝数量及宽度大小均大于其非超高侧裂缝数量及宽度大小,桥上底座板早期裂缝数量及宽度大小均与距梁端距离无关;(4)本研究成果可为无砟轨道系统设计计算和可靠度安全分析提供参考。
Research purposes: The recent researches on the reliability of longitudinally connected ballastless track are all based on the assumed empirical distribution model. In order to analyze the structural performance and state random distribution characteristics of it according to the measured data,the Xiaojiahe large bridge was took as the example to make the field measurement,and the statistics of the strength and cracking of track slab,base slab and wide-narrow joint on simply supported bridges were carried out.Research conclusions:( 1) The strength of the field ballastless track is approximately normally distributed. Among them,the probability density function of track plate strength obeys the normal distribution with the mean value of54. 56 MPa and variance of 0. 98 while that of base plate strength obeys the normal distribution with the mean value of36. 58 MPa and variance of 2. 15. Compared with the cast-in-place concrete base plate,the strength of the prefabricated track slab is closer to the theoretical value,and the dispersion is relatively small.( 2) The probability density function of the strength of wide-narrow joints approximately obeys the normal distribution with the mean value of45. 44 MPa and variance of 1. 52. It is difficult for the field cast-in-place wide-narrow joints to reach the theoretical strength. In order to prevent the cracks and damages of the wide-narrow joints in the later stage,it is suggested that both the construction technology and concrete grade should be improved.( 3) On the curved bridge,the crack width of the superelevation side of the base plate obeys the normal distribution with the mean value of 0. 11 mm and variance of0. 07,while that of the non-superelevation side approximately obeys the normal distribution with the mean value of0. 07 mm and variance of 0. 04. Both the crack number and width of the superelevation side are larger than those of the non-superelevation side. The number and width of early cracks on the base plate are independent of the distance from the bridge end.( 4) The research results can provide reference for the calculation and reliability safety analysis of ballastless track system.
作者
戴公连
葛浩
DAI Gonglian;GE Hao(Central South University,Changsha,Hunan 410075,China)
出处
《铁道工程学报》
EI
北大核心
2020年第9期1-6,共6页
Journal of Railway Engineering Society
基金
国家自然科学基金项目(51708560)
湖南省自然科学基金项目(2018JJ3672)
中国铁路总公司科技研究开发计划(2017G006-N)。
关键词
高速铁路
纵连无砟轨道
强度
裂缝
特征统计
high-speed railway
longitudinally connected ballastless track
strength
crack
characteristic statistics
