降水与蒸发交替作用下西北土遗址盐分迁移与赋存规律  

Migration patterns and occurrence laws of salinity in earthen sites in the northwest region under alternating precipitation and evaporation conditions

作　　者：谌文武[1,2] 王科玉 祁强 张少冉 王立 CHEN Wen-wu;WANG Ke-yu;QI Qiang;ZHANG Shao-ran;WANG Li(School of Civil Engineering and Mechanics,Lanzhou University,Lanzhou,Gansu 730000,China;Key Laboratory of Mechanics on Disaster and Environment in Western China of Ministry of Education,Lanzhou University,Lanzhou,Gansu 730000,China)

机构地区：[1]兰州大学土木工程与力学学院,甘肃兰州730000 [2]兰州大学西部灾害与环境力学教育部重点实验室,甘肃兰州730000

出　　处：《岩土力学》2024年第8期2209-2220,共12页Rock and Soil Mechanics

基　　金：国家重点研发计划(No.2020YFC1522201)。

摘　　要：中国西北干旱地区土遗址,广泛受到地基土盐渍作用的影响。针对当前土遗址载体研究不足的现状,基于室内试验,以NaCl为迁移盐分,借助电导率、含水率等参数及表面劣化情况探究了长城遗址体在短时强降雨-自然干燥循环作用下,地基与墙体根部盐分迁移规律。研究发现,随着降雨-干燥循环次数的增加,土遗址立面逐渐出现了底部崩解(掏蚀)、表面析盐、表皮开裂、空鼓等现象,土遗址根部毛细水上升、盐分迁移和表面劣化,3种现象互有关联。在经历数次循环后,地基中盐分供给模式发生了调整,地基-土遗址根部盐分迁移只在有限范围内进行,基于这些研究结果,得出了降雨-蒸发交替作用下地基与土遗址根部盐分迁移机制。所做研究可为土遗址根部酥碱掏蚀的防治提供参考。The earthen sites in the arid areas of northwest China are widely affected by the salinization of foundation soils.Due to the lack of research on earthen site foundations,this study investigates the salt migration patterns of the foundation and wall roots at the Great Wall site during short-term heavy rainfall and natural drying cycles.Conductivity,moisture content,and other parameters are utilized in laboratory experiments to analyze surface deterioration,with NaCl as the migration salt.It is observed that as the number of rainfall-drying cycles increases,the facades of earthen sites exhibit phenomena such as basal collapsing(erosion),salt efflorescence,epidermal cracking,and hollowing.The phenomena of capillary rise,salt migration,and surface deterioration in earthen sites are interconnected.After several cycles,the salt supply pattern in the foundation was adjusted,the salt migrate at the root of earthen sites is limited in scope.These findings elucidate the salt migration mechanism at the foundation roots and earthen sites during the alternation of rainfall and evaporation.This study offers insights for preventing and protecting against salinity erosion in earthen sites.

关 键 词：土遗址 盐胀 降雨入渗 毛细上升 水盐运移 

分 类 号：TU452[建筑科学—岩土工程]