摘要
季节冻土区的冻胀和融沉作用显著,对该地区构筑物造成了不同程度的冻害破坏,尤其对地下水埋深较浅区域尤为严重,故开展可对大尺寸模型进行不同地下水水位下单向冻融过程模拟的系统装置的研制,具有重要的科研意义和工程价值。研制的该冻融系统装置,主要包括箱体结构、制冷/热系统、边界温控系统、供电系统、地下水补给系统、保温隔热系统和量测系统等组成。箱体结构由6 mm厚钢板材料制作而成;制冷/热系统主要由基于帕尔贴效应的半导体制冷片组成实现制冷/热;边界温控系统主要依靠电子温控器进行控温;地下水补给系统主要利用改进型的马里奥特瓶进行地下水的补给;保温隔热系统主要采用V0级橡塑保温板;量测系统可根据试验目进行自由搭配组合。使用该试验装置对大尺寸新疆粉质黏土土样进行了在地下水埋深分别为80 cm和40 cm下的单向冻融过程试验研究,试验结果表明:在冻结和融沉过程中,温度的变化速率与土层距制冷/热板的距离成反比;冻结锋面的迁移可分为2个阶段;冻结过程中含水率变化分为快速和缓慢变化2个阶段;冻胀量的变化可分为2个阶段;融沉量的变化可分为3个阶段。温度、含水率、冻结锋面和冻融量变化等试验结果均证明了此试验装置的可靠性,此装置可为研制能对大尺寸模型进行开放条件下单向冻融模拟的设备提供借鉴。
The effect of freezing and melting in the seasonal frozen soil area is significant.It may cause various degrees of freezing damage to the structure of this area,especially serious for the areas where groundwater water is shallow.Therefore,it is of great scientific significance and engineering value to develop a system which can simulate the unidirectional freezing-thawing process under different groundwater levels with large-scale models.The freezing-thawing system consists of a box structure,refrigeration/heat system,boundary temperature control system,power supply system,groundwater recharge system,thermal insulation system and measurement system.The box structure is made of 6 mm thick steel plate material.The refrigeration/heat system is mainly composed of a semiconductor cooling sheet based on the Peltier effect to achieve refrigeration/heat.The boundary temperature control system mainly relies on the electronic temperature controller for temperature control.The groundwater recharge system mainly uses the modified Mariotte bottle for groundwater recharge.The thermal insulation system mainly adopts a V0-grade rubber and plastic insulation board.The measuring system can be combined freely according to the purpose of the test.Using this experimental device,the unidirectional freezing and thawing process of large size silty clay samples under groundwater depths of 80 cm and 40 cm is carried out.The test results show that in the process of freezing and thawing settlement,the change rate of temperature is inversely proportional to the distance between the soil layer and the refrigeration/heating plate.The migration of the freezing front can be divided into two stages.The change in water content in the freezing process can be divided into two stages:rapid and slow.The change in frost heaving can be divided into two stages,and the change in the thawing settlement can be divided into three stages.The test results for temperature,moisture content,frozen front and freezing-thawing change also show the reliability of the test device.This device can provide a reference for the development of equipment that can simulate unidirectional freezing-thawing under the open conditions for large-scale models.
作者
陈新瑞
宋玲
孙雯
许清峰
刘沛凯
惠强
李鑫鑫
吴浩
CHEN Xinrui;SONG Ling;SUN Wen;XU Qingfeng;LIU Peikai;HUI Qiang;LI Xinxin;WU Hao(College of Water & Architectural Engineering, Shihezi University, Shihezi, Xinjiang 832003, China;Hongshanzui Power Plant of Xinjiang Tianfu Energy Co., Ltd., Shihezi, Xinjiang 832000, China)
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2020年第3期69-78,共10页
Hydrogeology & Engineering Geology
基金
国家自然科学基金项目资助(51669031)。
关键词
冻融试验装置
地下水补给
大尺寸模型
单向冻融
黏土
freezing-thawing test device
groundwater recharge
large scale model
unidirectional freeze-thaw
clay