摘要
为揭示G214黄河源多年冻土区土的固结变形规律,为多年冻土段地基的加固处治提供理论依据和实用参考,选取G214黄河源多年冻土段为研究区,钻孔取样老路地基与天然地基土样,并依据室内土工试验规范开展固结试验。通过固结试验推导出老路地基与天然地基土样的固结系数、孔隙比、先期固结比等参数,并对这些数据进行处理分析。结果表明:老路地基土的固结变形量显著小于天然地基土,尤其在高荷载下差异更加显著;老路地基土的固结曲线整体较为平缓,而天然地基土的固结曲线则在初期就有较大的沉降变化;老路地基2.5~6.0 m土样先期固结比较低,天然地基土除0~1.5 m土层外的其他土样先期固结比较低;受全年温度波动影响,老路地基2.5~4.3 m土层在固结压缩过程中孔隙比变化显著,为其他层位土样的2.05倍;除2.5~4.3 m土层外,天然地基土的孔隙比变化幅度均高于老路地基土,表现出更强的可压缩性;老路地基最大沉降来源为2.5~4.3 m土层,浅层地基土沉降量小,天然地基的沉降最大来源于浅层土层,2.5~7.5 m土层对总沉降量同样具有较大贡献,天然地基的沉降量约为老路地基的1.37倍。地基处治工程中应针对沉降变形特征,结合软土地基处治方案与深层冻土保护思路进行加固处治。
To reveal G214 soil consolidation deformation rule in permafrost region G214 of Yellow River source,and provide theoretical and practical references for foundation reinforcement and treatment of permafrost sections,this study focused on Yellow River source G214 permafrost section.The soil samples from both old and natural road foundations were collected through drilling.The consolidation tests were carried out following the laboratory geotechnical testing standards.The consolidation tests were used to derive parameters for both old and natural foundation soils,e.g.,consolidation coefficient,void ratio,and preconsolidation ratio.Then,these data were processed and analyzed.The result indicates that the consolidation deformation of old foundation soil is significantly smaller than that of natural foundation soil,especially under high load.The consolidation curve of old foundation soil is generally flatter,whereas the consolidation curve of natural foundation soil shows substantial settlement variation in early stages.The pre-consolidation ratio of old foundation soil at 2.5-6.0 m depth is low,while the pre-consolidation ratio of natural foundation soil is low,except the 0-1.5 m soil layer.Due to annual temperature fluctuations,the void ratio changes significantly during consolidation compression process at 2.5-4.3 m old foundation layer,which is 2.05 times that of other layers.The void ratio variation amplitudes in natural foundation soil are generally greater than those in old foundation soil,indicating stronger compressibility,except 2.5-4.3 m layer.The maximum settlement of old foundation originates mainly from the 2.5-4.3 m soil layer,with the shallow foundation soil experiencing minimal settlement.The maximum settlement of natural foundation originates from shallow layers,and 2.5-7.5 m soil layer also contributes significantly to the total settlement.The settlement of natural foundation is approximately 1.37 times that of the old foundation.In foundation treatment engineering,the reinforcement and treatment should be conducted based on the settlement deformation characteristics,integrating soft soil foundation treatment methods with deep permafrost protection strategies.
作者
余建华
权磊
田波
李立辉
张盼盼
YU Jian-hua;QUAN Lei;TIAN Bo;LI Li-hui;ZHANG Pan-pan(Research Institute of Highway,Ministry of Transport,Beijing 100088,China)
出处
《公路交通科技》
CSCD
北大核心
2024年第S1期118-128,共11页
Journal of Highway and Transportation Research and Development
基金
国家重点研发计划项目(2023YFB2604800)
关键词
道路工程
固结特性
固结试验
多年冻土
孔隙比
地基处治
road engineering
consolidation characteristics
consolidation test
permafrost
void ratio
foundation treatment
