冻融循环对重塑碳酸盐渍土不排水强度影响研究  

Effect of freeze-thaw cycles on undrained strength of remoulded saline-alkali soil

作　　者：王中攀 丁黔 陈克政 杨扬[4] 张晓东 丁琳[1] 柳艳杰[1] WANG Zhongpan;DING Qian;CHEN Kezheng;YANG Yang;ZHANG Xiaodong;DING Lin;LIU Yanjie(School of Civil Engineering,Heilongjiang University,Harbin 150080,China;School of Hydraulic and Electric Power,Heilongjiang University,Harbin 150080,China;College of Engineering and Technology,Northeast Forestry University,Harbin 150040,China;College of Civil and Architectural Engineering,Heilongjiang Institute of Technology,Harbin 150050,China;Heilongjiang Longye Water Conservancy and Hydropower Engineering Construction Co.LTD,Harbin 150087,China)

机构地区：[1]黑龙江大学建筑工程学院,黑龙江哈尔滨150080 [2]黑龙江大学水利电力学院,黑龙江哈尔滨150080 [3]东北林业大学工程技术学院,黑龙江哈尔滨150040 [4]黑龙江工程学院土木与建筑工程学院,黑龙江哈尔滨150050 [5]黑龙江省隆业水利水电工程建设有限公司,黑龙江哈尔滨150087

出　　处：《冰川冻土》2023年第3期1026-1035,共10页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41071049);冻土工程国家重点实验室开放基金项目(SKLFSE201802,SKLFSE201919)资助。

摘　　要：为研究寒区碳酸盐渍土强度特征,建立冻融循环作用下碳酸盐渍土的修正邓肯-张模型,指导碳酸盐渍土地区的工程建设,利用GDS三轴对取自黑龙江省某地的碳酸盐渍土进行不同围压、不同冻融循环次数下的UU试验。通过曲线拟合,获得了土样强度指标c和φ、模型参数Κ和n、破坏比Rf与冻融循环次数N的数学模型,根据模型理论值与实测值对比分析修正了邓肯-张模型切线模量Ei,从而建立了考虑碳酸盐渍土冻融循环次数N的修正邓肯-张模型。结果表明:碳酸盐渍土经冻融后,其不排水应力-应变曲线呈应变硬化型,且碳酸盐渍土在经历三次冻融循环后,强度降低幅度最大,占整个强度劣化过程的71%以上;冻融后,碳酸盐渍土内摩擦角φ、黏聚力c和参数K逐渐降低,破坏比Rf呈现出先降低后增加,而参数n表现出先增加后减小的趋势。本文提出了冻融循环作用下的修正邓肯-张模型,且模型预测精度高。For fixing Duncan-Chang model and making it suitable for unconsolidated and undrained(UU)tests,establishing the modal which can describes saline-alkali soil strength curve of saline soil after freezing and thaw⁃ing cycles and guide the engineering construction of saline-alkali soil area.In this paper,GDS triaxial was used to conduct UU tests on saline-alkali soil taken from the place in Heilongjiang Province under different confining pressures and different freeze-thaw cycles.The relationship between soil sample strength index c andφ,model parameters K and n,break ratio Rf and the number of freezing-thawing cycles N were obtained by curve fitting.The tangent modulus Ei was modified according to the error comparison between model prediction results and the real value,so the modified Duncan-Chang model was established considering the number of freezing-thawing cy⁃cles N of saline-alkali soil.The results show that the undrained stress-strain curve of saline-alkali soil is strain hardening after freeze-thaw,and the strength of saline-alkali soil decreases the most after three freeze-thaw cy⁃cles,accounting for more than 71%of the whole strength deterioration process.After freezing and thawing,the internal friction angleφ,cohesion c and parameter K decrease gradually,and the break ratio Rf decreases firstly and then increases,while parameter n increases firstly and then decreases.The modified Duncan-Chang model considering the number of freezing-thawing cycles was established in this paper,and the predicted results are in good agreement with the experimental results.

关 键 词：修正邓肯-张模型 UU试验 碳酸盐渍土 冻融循环 强度 

分 类 号：P642.14[天文地球—工程地质学] TU411[天文地球—地质矿产勘探]