不同改良剂对红壤土水特征曲线及吸附强度的影响  

The Effect of Soil Conditioners on Water Characteristic Curves and Adsorption Strength of Red Loam Soil

作　　者：刘武江 段青松 杨松 熊寿德 保锐琴 黎李杨 张川 LIU Wujiang;DUAN Qingsong;YANG Song;XIONG Shoude;BAO Ruiqin;LI Liyang;ZHANG Chuan(Yunnan Academy of Agricultural Engineering,Kunming 650215,China;College of Hydraulic Engineering,Yunnan Agricultural University,Kunming 650201,China;Yunnan Geological Engineering Survey and Design Research Institute Limited Company,Kunming 650041,China;College of Resources and Environment,Yunnan Agricultural University,Kunming 650201,China;Yunnan Yuanke Land Consolidation and Rehabilitation and Planning&Design Limited Company,Kunming 650201,China;Research Center for Transition Development and Rural Revitalization of Resource-based Cities in China,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]云南省农业工程研究设计院,昆明650215 [2]云南农业大学水利学院,昆明650201 [3]云南地质工程勘察设计研究院有限公司,昆明650041 [4]云南农业大学资源与环境学院,昆明650201 [5]云南远科土地整治规划设计有限公司,昆明650201 [6]中国矿业大学中国资源型城市转型发展与乡村振兴研究中心,江苏徐州221116

出　　处：《灌溉排水学报》2023年第9期68-78,共11页Journal of Irrigation and Drainage

基　　金：国家自然科学基金项目(41867038);国土资源部公益性行业科研专项经费(201511003-3);国土资源部开放基金项目(YNTD2018KF05);云南省水利科技重大专项项目(2023BG204001)。

摘　　要：【目的】向边坡土壤内加入改良剂会对土体水分产生较大影响,揭示此过程中土水特征曲线及吸附强度的变化规律可为采用改良剂进行边坡治理提供依据。【方法】通过测定不同配比的糯米胶、木纤维、糯米胶/木纤维混施的红壤土的基质吸力ψ和体积含水率θv,绘制土水特征曲线并分析典型特征参数变化;采用直剪试验测定不同改良剂红壤饱和状态的内摩擦角φ,结合Fredlund双应力变量抗剪强度理论,分析不同改良剂对红壤吸附强度τψ的影响。【结果】(1)糯米胶和木纤维能提高土体饱和含水率θs,混合改良剂反之;糯米胶和混合改良剂会降低土水特征曲线的残余含水率θr,木纤维只有在较低或较高掺量时才会降低残余含水率,反之增高;3种改良剂均能提高土水特征曲线的进气值ψa,混合改良剂>糯米胶>木纤维;糯米胶会降低土水特征曲线的残余值ψr,木纤维反而增加残余值,混合改良剂介于二者之间且高于素土;糯米胶的土水特征曲线斜率|k|最大,其次是混合改良剂和木纤维。(2)不同改良剂红壤随θv降低,ψ增加,吸附强度τψ增大,抗剪强度随ψ增加的速率减小。在23.73%~30.76%体积含水率区间,2.5%纤维和5.0%纤维的吸附强度相对较大,其次是素土、5.0%混合和2.5%混合,最后是2.5%胶、5.0%胶和0.5%胶。【结论】(1)糯米胶主要影响|k|值,致使土体水分散失速率加快;木纤维对θs、θr和ψr的影响最大,土体保水性好,水分不易流失;混合改良剂以提高ψa为最优,土体初期(边界效应阶段)不易失水,中后期受糯米胶成分的影响,持水能力减弱。(2)不同改良剂增大τψ的效果由强到弱依次为:木纤维>糯米胶>混施。【Objective】Amending degraded soils with soil conditioners is a technique widely used to improve soil quality.Different conditioners are commercially available but their effect on soil release curve is less understood.The purpose of this paper is to compare change in water characteristic curves of a red loam soils amended using different soil modifiers.【Method】The soil was amended by glutinous rice gum,wood fiber,and their mixture at different ratios.We measured the change in matrix suction(ψ)and volumetric soil water content(θv)of each soil sample.The internal friction angle(φ)of the soil at saturation was determined using the direct shear test method,from which we calculated the adsorption strength(τψ)of the soil using the Fredlund double stress variable shear strength.【Result】①Glutinous rice gum and wood fiber both increased the saturated soil water content(θs),while their mixture reducedθs.Glutinous rice gum and its mixture with wood fiber reduced the residual soil water content(θr),while the wood fiber working alone only reduced the residual water content when the amendment ratio was low or high.All three modifiers increased the air-entry value(ψa),with the increase ranked in the order of the mixture>glutinous rice gum>wood fiber.Glutinous rice gum reduced the residual matric potential(ψr),while the wood fiber increasedψr,with the mixture in the between with itsψr higher than that of the non-amended soil.The matric potential decreased fastest as soil water content increased in the glutinous rice gum treatment,followed by the mixture and wood fiber.②All conditioners increased the adsorption strengthτψ,and the shear strength decreased with the increase inψ.For soil water content in the range of 23.73%~30.76%,amending the soil with 2.5%~5.0%of wood fiber gave the highest adsorption strength,followed by non-amended soil,the amendment by 2.5%~5.0%of mixture,and the amendment by 0.5%~5.0%of glutinous rice gum.【Conclusion】①Glutinous rice gum mainly reduced the ability of the soil

关 键 词：土壤改良剂 红壤 基质吸力 土水特征曲线 吸附强度 

分 类 号：S284[农业科学—农业水土工程]