摘要
水分迁移引起的分凝冻胀是土体冻胀变形的主要来源,而掌握冻结过程中水分迁移规律是揭示土体冻胀机理的关键。为探究钢纤维改良土抑制冻胀机理,利用改进的冻胀装置设计进行了独立补水条件下的分层冻胀试验,获得如下结论:冻结过程中试样下部的冻胀作用会引起上部未冻土的排水,冻结过程中0.5%掺量试样的中层与上层土体排水量分别占相应土体水分迁入量的1.22%和3.45%;掺入钢纤维可明显减小试样的补水量,相比于未掺钢纤维试样,0.5%掺量试样的中层和上层补水量可分别减小10.19%,17.87%;钢纤维掺量及长度的增加不仅可促进试样中水分排出,而且会抑制土体中冰透镜体生长,降低外部水分迁入量,从而减小试样冻胀率。研究结果表明,试样中掺入钢纤维后引起的排水效应及限制冰透镜体的生长过程,是钢纤维改良土抑制冻胀的主要原因。
The segregation frost heave caused by water migration is the main source of frost heave,and the water migration law is the key factor to reveal the mechanism of frost heave of soils in the freezing process.In order to explore the mechanism of inhibiting the frost heave of steel fiber-improved soil,the one-dimensional frost heave tests on the steel fiber-improved soil under the layered independent water supplement condition are carried out by using the improved frost heave devices.The following conclusions are obtained.Firstly,the frost heave in the lower part of the sample will cause the drainage of the unfrozen soil in the upper part,and the amount of water discharged from the middle and upper soil layers of the sample with steel fiber content of 0.5%during the freezing process accounts for 1.22%and 3.45%of the corresponding water inflow.Secondly,the steel fiber added in the soils can obviously reduce the water supply in the freezing process.Compared with the sample without steel fiber,the water replenishment in the middle and upper layers of the sample with steel fiber content of 0.5%decreases by 10.19%and 17.87%.Thirdly,the increase of content and length of the steel fiber can promote the water discharge from the sample and inhibit the growth of ice lens in the soils,which can reduce the amount of external water intake and reduce the frost heave deformation.The research results show that the drainage effects and the restriction of ice lens growth caused by the steel fiber are the main reasons for the inhibition of frost heave in the steel fiber-improved soil.
作者
石荣剑
黄丰
岳丰田
姬嘉骏
李逸辰
SHI Rongjian;HUANG Feng;YUE Fengtian;JI Jiajun;LI Yichen(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;Xuzhou Construction Engineering Testing Center Co.,Ltd,Xuzhou 221003,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2023年第7期1430-1437,共8页
Chinese Journal of Geotechnical Engineering
基金
国家高技术研究发展计划(“863”计划)项目(2012AA06A401)。
关键词
人工冻结
钢纤维改良土
水分迁移
分层冻胀
室内试验
artificial freezing
steel fiber-improved soil
moisture migration
delamination frost heave
laboratory test
