摘要
高速铁路路基沉降计算与分析是路基设计及评估的重要环节。为准确计算高速铁路中低压缩性土路基沉降,从中低压缩性土的工程特性出发,基于考虑时间效应的压缩层厚度计算方法和分层连续加载下地基沉降计算理论,建立更适应于高铁路基荷载特征的高铁中低压缩性土路基沉降计算方法。利用吉珲铁路珲春试验工点得到的地基土物理和力学指标,计算路堤分级堆载条件下,不同埋深处上层硬塑粉质黏土和下层全风化泥质粉砂岩地基的时效变形规律。结果表明,在路基填筑过程中,基底附加应力计算方法获取的基底附加应力与实测值较为吻合。进一步对比理论与现场实测结果发现,截至第700天,地基总沉降的计算误差约2mm;地基分层沉降的理论值与计算值误差在±5%以内,验证了计算方法的可靠性和准确性;针对考虑时间效应的压缩层厚度计算确定的地基压缩层厚度,其随路基填筑高度呈线性正相关。上述方法不仅为合理选择并优化高速铁路中低压缩性土的地基加固措施及方案提供了关键的技术支撑,也为精确计算和预测工后沉降提供了保障。
The calculation of subgrade settlement of high-speed railway is an important part of design and evaluation of subgrade.To accurately calculate the subgrade settlement of medium-low compressible soils for high-speed railways,a new calculated model of the subgrade settlement more suitable for the load characteristics of the high-speed railway is established based on its engineering properties and the method of the compression layer thickness involving the time-effect and the theory of the subgrade settlement under layered continuous loading.Using the physical and mechanical parameters of the basement soil obtained from the Hunchun site of Jilin-Hunchun Railway,the deformation law of the upper layer of hard plastic silty clay and the lower layer of fully weathered argillaceous siltstone foundation with different depths under stage continuous loading is calculated.The results show that during the subgrade filling,the calculated additional stress is in good agreement with the measured value.Further comparison of theoretical and monitoring results finds that by the 700th day,the error of the total settlement is about 2 mm.Moreover,the error between the theoretical and calculated data of stratified settlement is within±5%,fully verifying the reliability and accuracy of calculated method.The thickness of the compression layer considering the time effect has a linear positive correlation with the height of embankment.The above methods not only provide key technical support for the rational selection and optimization of reinforced measures of medium-low compressible soils for the foundation of high-speed railways,but also provide a guarantee for accurate calculation and prediction of post-construction settlement.
作者
陈善雄
崔俊杰
罗强
王祥
王亚飞
王亚威
CHEN Shanxiong;CUI Junjie;LUO Qiang;WANG Xiang;WANG Yafei;WANG Yawei(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;China Railway Engineering Design and Consulting Group Co.,Ltd.,Beijing 100055,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China)
出处
《铁道标准设计》
北大核心
2023年第7期24-29,50,共7页
Railway Standard Design
基金
铁道部科技研究开发计划项目(2010G003-F)
中国中铁股份有限公司科研课题(重点-72-2010)。
关键词
中低压缩性土
铁路路基:分级连续加载
分层沉降
时间效应
压缩层厚度
高速铁路
medium-low compressible soil
railway subgrade
graded continuous loading
layered settlement
time effect
thickness of compression layer
high-speed railway
