辽西地区风积土冻融特性与冻融过程结构性演变规律试验研究  

TESTING RESEARCH ON FREEZING-THAWING CHARACTER AND STRUCTURAL EVOLVEMENT REGULARITY DURING FREEZING-THAWING PROCESS OF AEOLIAN SOIL IN WESTERN AREA OF LIAONING PROVINCE

作　　者：张向东[1] 刘功勋[2] 栾茂田[2] 

机构地区：[1]辽宁工程技术大学土木建筑工程学院,辽宁阜新123000 [2]大连理工大学土木水利学院

出　　处：《岩石力学与工程学报》2008年第S1期2946-2952,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(50478033);辽宁省教育厅科学技术研究项目(2004D120)

摘　　要：介绍新型冻融试验装置及其应用情况,并利用该试验装置对辽西地区典型风积试样在不同温度梯度、荷载和水分补给条件下进行冻融试验,从而揭示风积土冻胀与融沉规律。试验结果表明:随着温度梯度的增大,最大冻胀量和融沉值有不同程度的减小;无论在封闭系统还是在开敞系统中,外力的存在都对冻胀起到抑制作用,融沉值也会随着荷载的增大而减小;外界水分的补给会使最终冻胀量和融沉值都显著增加。风积土在冻融作用下产生冻胀融沉变形,宏观力学性质和微观结构也发生相应的变化,主要是由于土的结构性得以改变,也就是冻融作用破坏了土颗粒间的连接力,同时使土颗粒得以重新排列。将冰率作为结构性参数,针对不同水分场和应力场对辽西地区风积土冻融过程结构性演变规律进行研究。A new device for freezing-thawing test and the application is introduced. By using this device,the typical aeolian soil samples in the western area of Liaoning Province are frozen and thawed under different conditions of temperature gradients,load and water supply. By doing so,the regularity of frost heave and thaw settlement is illuminated. The test results can be drawn as follows:(1) the maximal swelling magnitude and thaw collapse value decrease with the increase of the temperature gradient;(2) not only in the closed system but also in the open system,the external force suppresses the swelling,and the thaw collapse value also decreases with the increase of the load;and (3) the external water supply will increase markedly the ultimate swelling magnitude and thaw collapse value. The displacement caused by freezing and thawing generates and the change of the macroscopic mechanical property and microscopic structure. This is mainly because the structure of the aeolian soil is changed;the bond force between the soil particles is damaged,and the soil particles rearranges. The structure evolvement regularity of aeolian soil in the western area of Liaoning Province during the period of freezing and thawing is studied under different moisture fields and stress fields by using the ice efficiency as the structure parameter.

关 键 词：土力学 风积土 冻融 耦合 冰率 结构性 

分 类 号：TU43[建筑科学—岩土工程]