降雨作用下硫酸盐渍土水–热–盐迁移及变形特性试验研究  

Experimental study on water-heat-salt migration and deformation characteristics of sulfate saline soil under rainfall

作　　者：周志雄 周凤玺[1] 张明礼[1] 马强 ZHOU Zhixiong;ZHOU Fengxi;ZHANG Mingli;MA Qiang(School of Civil Engineering,Lanzhou University of Technology,Lanzhou,Gansu 730050,China;School of Civil Engineering,Qinghai University,Xining,Qinghai 810016,China)

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050 [2]青海大学土木工程学院,青海西宁810016

出　　处：《岩石力学与工程学报》2024年第8期2056-2068,共13页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(12362032,11962016);甘肃省重点研发计划(23YFFA0063)。

摘　　要：为明确降雨作用下硫酸盐渍土水–热–盐迁移及其变形特性,以甘肃河西地区的气候环境特点以及盐渍土类型为背景,在自主研发的室内底板–大气双控温模型箱内部制作硫酸钠盐渍土天然场地的几何相似比模型(1∶6),首次结合地表能量收支平衡特征研究无降雨和有降雨2种工况下硫酸钠盐渍土内部多物理场耦合变化的特点。研究结果表明:降雨作用会导致反射短波辐射、入射长波辐射以及地表温度减小,地表净辐射以及地表蒸发速率增加,且增加趋势与降雨量相关。受降雨作用影响,土体内部含水量和电导率增加,土体热通量和温度降低。并且,降雨作用导致硫酸盐渍土内部的放热时间增长。此外,降雨作用对硫酸盐渍土内部水–热–盐各物理场的影响随着深度的增加逐渐减弱。一年四季交替过程中,硫酸盐渍土经历了先融沉后盐冻胀的变形过程。并且受降雨作用的影响,硫酸盐渍土的融沉变形和盐冻胀变形呈现不同程度的增加。研究结果为应对气候变化背景下盐渍土地区的环境灾变问题和工程问题提供一定的指导。To clarify the water-heat-salt migration and deformation characteristics of sulfate saline soil under rainfall,based on the climate characteristics and saline soil types of the Hexi region in Gansu Province,a geometric similarity ratio model(1:6)of the natural site of sodium sulfate saline soil was made using the self-developed indoor baseplate-atmospheric dual-temperature control model box.Combined with the surface energy budget balance characteristics for the first time,this natural site model was used to study the multi-physical fields coupled changes within the sodium sulfate saline soil under no rainfall and rainfall.The results show that rainfall can lead to a decrease in reflected shortwave radiation,downward longwave radiation and surface temperature,an increase in surface net radiation and surface evaporation rate,and the increasing trend is related to rainfall.The rainfall leads to an increase in soil water content and conductivity,as well as a decrease in soil heat flux and temperature.Meanwhile,the rainfall leads to an increase in the heat release time of sulfate saline soil.In addition,the influence of rainfall on the water-heat-salt physical fields within the sulfate saline soil gradually weakens with increasing depth.During the transition of four seasons throughout the year,the sulfate saline soil undergoes a deformation process of first thawing settlement and then salt frost heave.Moreover,the thawing settlement and salt frost heave deformation of sulfate saline soil show varying degrees of increase under the influence of rainfall.The research results provide certain guidance for addressing environmental disasters and engineering issues in salted regions under the background of climate change.

关 键 词：土力学 硫酸盐渍土 降雨作用 地表能量 水–热–盐迁移 盐冻胀变形 模型试验 

分 类 号：TU43[建筑科学—岩土工程]