摘要
针对地铁隧道人工冻结法施工过程中土层冻胀融沉变形控制难题,以上海地区典型重塑饱和粉质黏土为研究对象,开展了有无补水(无荷载)、不同荷载(补水)以及不同融沉方式下土体的冻胀融沉试验。试验结果表明:(1)在相同的冷端温度和温度梯度下,补水条件致使冻结锋面稳定时所需的时间比不补水条件长;(2)随着竖向荷载的增加,冻结锋面高度与冻结时间、冻结锋面平均移动速率之间的关系均为一阶衰减指数函数;(3)随着竖向荷载的增加,土体的冻胀变形、补水量和最终融沉量均减小,说明荷载抑制土体冻胀的同时也抑制土体融沉;(4)相同荷载条件下,土体经冻融后,在卸载融沉方式下发生膨胀,而在加载融沉方式下发生沉降,且沉降量随着荷载的增加而增大。
Aiming at solving the difficult problem of controlling the frost heave and thaw settlement deformation of soil layers during the construction of subway tunnels by artificial freezing method,the frost heave and thaw settlement tests of soil layers with or without water replenishment(no load),different loads(water replenishment),and different thaw settlement methods are conducted using a typical remolded saturated silty clay in Shanghai as the research object.The test results show that:(1)Under the same cold junction temperature and temperature gradient,the time required for stabilizing the frozen front due to water replenishment conditions is longer than that due to no water replenishment conditions.(2)As the vertical load increases,the relationship between the height of the frozen front and the freezing time,the average moving speed of the frozen front is a first-order decaying exponential function.(3)As the vertical load increases,the frost heave deformation,water replenishment and final thaw settlement of the soil mass all decrease,which indicates that the load inhibits both frost heave and thaw settlement of the soil mass.(4)Under the same load conditions,after freezing and thawing,the soil expands under unloading and thawing settlement,while the soil settles under loading and thawing settlement,and the settlement increases with the increase of load.
作者
樊文虎
周桂云
陈盈盈
胡继锟
AN Wen-hu;ZHOU Gui-yun;CHEN Ying-ying;HU Ji-kun(Jinling Institute of Technology,Nanjing 211169,China)
出处
《金陵科技学院学报》
2023年第1期64-71,共8页
Journal of Jinling Institute of Technology
基金
金陵科技学院高层次人才科研启动基金(jit-b-202125)。
关键词
粉质黏土
冻胀
融沉
荷载
补水
saturated silty clay
frost heave
thaw settlement
load
water supply
