摘要
高速铁路无砟轨道对路基变形极其敏感,红层软岩区路基在服役期持续上拱变形已造成多条线路降速运行并返工整治,厘清路基实测变形的时空演化规律是揭示路基长期上拱变形内在机理的基础。以成渝客运专线内江北站上拱病害路基为依托,结合现场调查、地质钻孔和路基长期变形监测手段,系统阐明工程区工程地质及水文地质环境,并分析路基变形在时间尺度和空位维度上的变化特征。研究结果表明:病害路基位于典型川中红层软岩区,构造影响甚微,基底为近水平红层泥岩夹砂岩或砂泥岩互层,地表水和地下水较发育。路基上拱变形随时间缓慢增长,A段路基基底以泥岩为主,路堑开挖深度越大、上拱变形量越大,且上拱变形速率与大气降雨量一致。B段路基基底砂岩层较厚,上拱变形量相对较小,并且变形与大气降雨、路堑开挖深度和基底泥岩层相对厚度无显著相关性,变形随时间呈近似线性增长。路基长期变形是基底红层软岩在赋存水、力条件下膨胀和蠕变的综合效应,不能简单通过路堑开挖深度或基底泥岩相对厚度评价红层软岩路基服役期上拱风险程度。红层软岩路基上拱变形是开挖后地基岩体赋存水、力环境改变诱发的复杂时效性变形过程,研究成果可为后续揭示路基长期上拱变形机理及建立理论模型奠定基础。
It is of great sensitive for ballastless track subgrade of high-speed railway to deformation.Several high-speed railway lines in the red-bed soft rock mass region had to be slowed down or even renovated due to the long-term heave of the subgrade.Clarifying the spatial and temporal evolution of subgrade is the basis to reveal its long-term heave mechanism.By taking the disaster subgrade project in Neijiang North station as an example,a systematic clarification of the engineering geology and hydrogeological environment of the project area was achieved through field investigation,geological drilling,and long-term deformation monitoring of the subgrade.This enabled an analysis of the spatial and temporal evolution characteristics of the subgrade's deformation.The results show that,the problematic subgrade is located in the typical red-bed soft rockmass area in the middle of Sichuan basin,the substrate is nearly horizontal red-bedded mudstone with sandstone and sand-mudstone interbedded,and the surface water and groundwater are well developed.The heave deformation of subgrade increased slowly with time,the heave in section A was consistent with the atmospheric rainfall,and the greater the excavation depth of the subgrade,the greater the heave.The heave in section B was relatively small,and there was no significant correlation between heave and atmospheric rainfall,excavation depth and the relative thickness of mudstone.The heave increased approximately linearly with time.It was the coupled effect of time-dependent swelling and creep of red-bed soft rockmass that induced long-term heave of subgrade.The long-term deformation of the subgrade is a comprehensive effect of the expansion and creep of red-bed soft rockmass in the basement under the condition of seepage and stress,the degree of heaving risk for red-bed soft rockmass subgrade during its service period cannot be evaluated simply by the excavation depth or the relative thickness of basement mudstone.It is a complex time-dependent deformation process for the heave
作者
钟志彬
李安洪
吴沛沛
邓荣贵
ZHONG Zhibin;LI Anhong;WU Peipei;DENG Ronggui(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2023年第10期3625-3637,共13页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(51808458)
四川省自然科学基金资助项目(2022NSFSC0403)
中国国家铁路集团有限公司重大课题(K2019G045)。
关键词
红层软岩
高速铁路路基
上拱变形
时空演化
膨胀
蠕变
red-bed soft rockmass
high-speed railway subgrade
heave deformation
spatial-temporal evolution
swelling
creep
