引江济淮工程膨胀土地段渠坡生态处治技术  

Ecological treatment of the channel in expansive soil section of the Water diversion project from the Yangtze to Huaihe River

作　　者：龚壁卫[1] 许晓彤 胡波[1] GONG Biwei;XU Xiaotong;HU Bo(Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China;Anhui Provincial Group Limited from Yangtze-to-Huaihe Water Diversion,Hefei 230000,China)

机构地区：[1]长江水利委员会长江科学院,水利部岩土力学与工程重点实验室,武汉430010 [2]安徽省引江济淮集团有限公司,合肥230000

出　　处：《南水北调与水利科技（中英文）》2023年第5期1006-1012,共7页South-to-North Water Transfers and Water Science & Technology

基　　金：安徽省引江济淮集团有限公司科技项目(YJJH-ZT-ZX-20191031216,YJJH-ZT-ZX-20230118528);中央级公益性科研院所基本科研项目(CKSF2023327/YT)。

摘　　要：围绕引江济淮工程膨胀土地段河渠边坡水泥改性土换填层易碱化板结、植物难以生长和局部弱膨胀土渠坡的简化处理等工程实际问题,以生态优先、技术创新为原则,采用现场试验、室内单元体测试和数值分析等手段,开展系统的研究工作。研发一种改善水泥改性土种植效果的生态基材,提出一种新型膨胀土双层护坡结构,并研究提出根据实际土层膨胀特性和含水状态进行弱膨胀土边坡的处理原则。现场中试和运用效果表明:研发的生态基材能适应水泥改性土的种植需要,使边坡实现良好的绿化效果,双层护坡结构较好地实现了膨胀土边坡防止降雨入渗和水分蒸发的双重防护要求;同时,还可利用砂土层的压重效果,抑制土层的膨胀变形。研究成果为引江济淮的工程设计和后期运行管理提供了技术支撑,同时,也为膨胀土地段渠坡生态处治探寻了新的方向。Total length of the Yangtze-to-Huaihe Water Transfer Project is 723 km,more than 100 km of the river section is distributed with weak and medium expansive soil,and the maximum excavation depth of the canal is 46 m.The stability of the expansive soil section is one of the key technical problems of the project.In the preliminary design stage,the treatment measures of over digging,replacing and filling cement-modified soil were proposed for the expanded land section,but some ecological and environmental problems were generated,such as the cement modified soil is easy to be alkali,and makes it difficult for plants to grow.Moreover,slope overcutting would produce a large amount of waste soil which is adverse to the ecological environment.Whether simplified treatment measures can be applied to some weak expansion channels with slope heights less than 10 m is a question that needs to be addressed.Under the principle of ecological priority and technological innovation,the researchers carried out systematic research work using field experiments,indoor unit tests,and numerical analysis.The ecological restoration scheme using surface cultivated soil and grass was put forward through field sampling tests and numerical analysis for the low river embankment in the weak expansive soil around Chaohu Lake.An ecological substrate was developed to solve the problems such as soil alkali plate and plant growth difficulty in the medium expansive cement-modified soil replacement layer.The field pilot test proved that the ecological substrate is a new kind of ecological slope planting material.An ecologically friendly expansive soil slope protection structure is proposed using unsaturated soil theory based on the characteristics of a large difference in permeability coefficient between sand and clay.This structure can better solve the dual protection requirements of expansive soil slopes to prevent rainfall infiltration and water evaporation.At the same time,it can also use the compression effect of the sand layer to restrain the expans

关 键 词：引江济淮 膨胀土 生态修复 水泥改性土 双层护坡结构 

分 类 号：TU43[建筑科学—岩土工程]