摘要
钢管冻土协同结构是有效控制冻胀融沉影响的新冻结模式,冻结过程中控制冻结壁边界的发展是抑制冻胀融沉环境影响的关键。以上海地铁18号线江浦路站冻结加固工程为背景,基于相似理论设计进行了钢管冻土协同结构冻结壁边界发展过程的模型试验,分析钢管和循环水对协同结构冻结壁边界发展过程的影响规律,获得以下结论:冻结壁边界位置的钢管不仅可以抑制冻土向外发展,而且会明显增大冻结壁边界位置的温度梯度,使形成的冻结壁更均匀,冻结32d时单排和双排钢管内、外侧温差分别可达到11.2℃和7.6℃,而钢管外侧冻土的温度较冻结管下部对应位置偏高6.7℃和10.7℃。冻土边界位置4℃的循环水可有效控制冻土边界向外扩展,进一步提升冻结壁的均匀性,冻结32d时冻土边界位置钢管内外侧温差达到18.3℃,钢管外侧冻土的温度较冻结管下部对应位置偏高16.9℃。研究结果表明,冻结壁边界位置布设的钢管或4℃的循环水均可有效控制冻土边界的扩展,提高形成冻结壁的均匀性,显著削弱冻结过程中冻胀对周围环境的影响,而边界位置4℃循环水的控制效果更好。
Steel pipe-frozen soil synergistic structure is a new freezing model,controlling the development of the frozen wall boundary during the freezing process is the key to restraining the impact of frost heave and thaw settlement on the environment.Taking the freezing reinforcement project of Jiangpu Road Station of Shanghai Metro Line 18 as the background,model tests were designed and conducted based on similar theoretical,which on the development process of frozen wall boundary of steel pipe-frozen soil synergistic structure,analysing the influence law of steel pipe and circulating water on the boundary development,and conclusions were drawn as followed:The development of frozen soil can be inhibited by steel pipe set at the boundary of the frozen wall,which can also expand the temperature gradient at the boundary of the frozen wall,making the frozen wall more uniform.When freezing 32 days,the temperature difference between the inner and outer sides of single-row and double-row steel pipes can reach 11.2℃and 7.6℃,while the temperature of the frozen soil outside the steel pipe is 6.7℃and 10.7℃higher than the corresponding position at the bottom of the freezing pipes.The outward expansion of frozen soil boundary can be effectively controlled by 4℃of the circulating water,further improving the uniformity of the frozen wall.The temperature difference between the inner and outer sides of the frozen soil boundary steel pipes reaches 18.3℃when freezing 32 days,and the temperature of the frozen soil outside the steel pipes is 16.9℃higher than the corresponding position at the lower part of the freezing pipes.The research results show that the expansion of the frozen soil can be effectively controlled by the steel pipes or 4℃circulating water placed at boundary of the frozen wall,improving the uniformity of the frozen wall,and significantly weakening the influence of frost heave on the surrounding environment during the freezing process,while the effect of 4℃circulating water at the boundary position is better.
作者
黄丰
石荣剑
岳丰田
王坤
HUANG Feng;SHI Rongjian;YUE Fengtian;WANG Kun(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2022年第S01期3063-3072,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家高技术研究发展计划(863)计划(2012AA06A401)
关键词
土力学
人工冻结技术
钢管冻土协同结构
冻结壁边界发展
冻结温度场
模型试验
soil mechanics
artificial freezing technology
steel pipe-frozen soil synergistic structure
frozen wall boundary development
freezing temperature field
model test
