發(fā)布時(shí)間：2021-05-09 16:13

　　季節(jié)性凍融循和不同初始土壤含水量對(duì)土壤剪切應(yīng)力有重要影響,其進(jìn)而影響坡面水蝕過程;然而目前凍融循環(huán)對(duì)坡面水蝕過程機(jī)理的影響研究還不十分清楚,特別是凍融循環(huán)對(duì)東北黑土區(qū)農(nóng)地土壤抗侵蝕能力的影響研究還相對(duì)薄弱。因此,本研究以黑龍江省黑土區(qū)的克山縣（KS）和賓縣（BX）為研究區(qū),通過設(shè)計(jì)5個(gè)凍融循環(huán)次數(shù)（0、1、3、5和7次）、3個(gè)初始土壤含水量（16.5%、24.8%和33.0%）和2種試驗(yàn)土壤處理（擾動(dòng)土和原狀土）和采用土壤直剪試驗(yàn),研究了凍融循環(huán)次數(shù)和土壤初始含水量對(duì)土壤剪切應(yīng)力的影響,研究結(jié)果加深了對(duì)凍融作用影響坡面土壤侵蝕機(jī)理的認(rèn)識(shí),同時(shí)也為黑土區(qū)侵蝕防治提供了科學(xué)依據(jù)。主要研究結(jié)論如下:（1）土壤剪切應(yīng)力和土壤粘聚力皆隨凍融循環(huán)次數(shù)和前期土壤含水量的增加而減少。當(dāng)凍融循環(huán)從0次增加到7次,BX和KS土壤剪切應(yīng)力分別降低8.6%¹8.0%和13.1%¹8.0%。當(dāng)前期土壤含水量分別為16.5%、24.8%和33.0%,5次凍融循環(huán)使BX土壤粘聚力分別減少70.9%、71.1%和65.9%和KS土壤粘聚力分別減少56.6%、61.7%and... 

【文章來源】：西北農(nóng)林科技大學(xué)陜西省 211工程院校 985工程院校 教育部直屬院校

【文章頁數(shù)】：63 頁

【學(xué)位級(jí)別】：碩士

【文章目錄】：
ABSTRACT
摘要
CHAPTER 1 INTRODUCTION
    1.1 Background
    1.2 Research significances
    1.3 Literature review
        1.3.1 The distribution of mollisol
        1.3.2 Freeze-thaw effects
        1.3.3 Effects of freeze-thaw cycle on soil structure
        1.3.4 Effect of initial soil water content on soil shear strength
        1.3.5 Measurement of soil shear strength
CHAPTER 2 RESEARCH CONTENTS AND METHODS
    2.1 Objectives
    2.2 Research contents
        2.2.1 Effects of freeze-thaw cycles on soil shear stress
        2.2.2 Effects of initial soil water content on soil shear stress
        2.2.3 Comparison of soil shear stress between remolded and undisturbed soils
    2.3 Research methods
        2.3.1 Study area
        2.3.2 Experimental design
        2.3.3 Direct shear test
        2.3.4 Soil sampling processes
        2.3.5 Technical route
    2.4 Data analysis and calculating method
        2.4.1 Data analysis
        2.4.2 Calculating method
CHAPTER 3 EFFECTS OF FREEZE-THAW CYCLES ON SOIL SHEAR STRESS
    3.1 Introduction
    3.2 Material and method
    3.3 Results and discussion
    3.4 Conclusion
CHAPTER 4 EFFECTS OF INITIAL SOIL WATER CONTENT ON SOIL SHEAR STRESS
    4.1 Introduction
    4.2 Materials and method
    4.3 Results and discussion
    4.4 Conclusion
CHAPTER 5 COMPARISONS OF SHEAR STRESS BETWEEN REMOLDED AND UNDISTURBED SOILS
    5.1 Introduction
    5.2 Material and method
    5.3 Results and discussion
    5.4 Conclusion
CHAPTER 6 CONCLUSIONS AND PERSPECTIVES
    6.1 Main conclusions
    6.2 Perspectives
REFERENCES
ACKNOWLEDGEMENTS
BIOGRAPHY


【參考文獻(xiàn)】：
期刊論文
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[3]凍融循環(huán)對(duì)含鹽土物理力學(xué)性質(zhì)影響的試驗(yàn)研究[J]. 邴慧,何平.  巖土工程學(xué)報(bào). 2009(12)
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