工程地质学报
工程地質學報
공정지질학보
2014年
6期
1046-1051
,共6页
蔡光华%薛强%刘松玉%陆海军
蔡光華%薛彊%劉鬆玉%陸海軍
채광화%설강%류송옥%륙해군
压实黏土%湿干循环%开裂%微观结构%孔隙率
壓實黏土%濕榦循環%開裂%微觀結構%孔隙率
압실점토%습간순배%개렬%미관결구%공극솔
Compacted clay%Wetting-drying cycle%Cracking%Microstructure%Porosity
开展了湿干循环作用下压实黏土的开裂试验和微观结构特性研究，分析了湿干循环作用对黏土开裂和孔隙结构的影响，将压汞试验（MIP）和扫描电镜（SEM）的结果与宏观开裂进行比较。结果表明：湿干循环作用显著影响了压实黏土的开裂，用开裂因子表征黏土的开裂程度，开裂因子随含水率减小而增大并明显大于湿干循环作用前；随湿干循环次数的增加，黏土孔隙的总体积、中间孔径、平均孔径、平均孔隙率和团粒内孔隙均在增加，而黏土的颗粒内孔隙、颗粒间孔隙和团粒间孔隙却在减小。湿干循环作用使黏土体从大团粒逐渐转化为小颗粒，并增大了土颗粒的凸凹性，分析SEM二值化图像得知土体孔隙率均在增加；用压汞法和扫描电镜法分析和解释土体开裂是可行的，所得的微观孔隙特征与宏观开裂规律基本相符。
開展瞭濕榦循環作用下壓實黏土的開裂試驗和微觀結構特性研究，分析瞭濕榦循環作用對黏土開裂和孔隙結構的影響，將壓汞試驗（MIP）和掃描電鏡（SEM）的結果與宏觀開裂進行比較。結果錶明：濕榦循環作用顯著影響瞭壓實黏土的開裂，用開裂因子錶徵黏土的開裂程度，開裂因子隨含水率減小而增大併明顯大于濕榦循環作用前；隨濕榦循環次數的增加，黏土孔隙的總體積、中間孔徑、平均孔徑、平均孔隙率和糰粒內孔隙均在增加，而黏土的顆粒內孔隙、顆粒間孔隙和糰粒間孔隙卻在減小。濕榦循環作用使黏土體從大糰粒逐漸轉化為小顆粒，併增大瞭土顆粒的凸凹性，分析SEM二值化圖像得知土體孔隙率均在增加；用壓汞法和掃描電鏡法分析和解釋土體開裂是可行的，所得的微觀孔隙特徵與宏觀開裂規律基本相符。
개전료습간순배작용하압실점토적개렬시험화미관결구특성연구，분석료습간순배작용대점토개렬화공극결구적영향，장압홍시험（MIP）화소묘전경（SEM）적결과여굉관개렬진행비교。결과표명：습간순배작용현저영향료압실점토적개렬，용개렬인자표정점토적개렬정도，개렬인자수함수솔감소이증대병명현대우습간순배작용전；수습간순배차수적증가，점토공극적총체적、중간공경、평균공경、평균공극솔화단립내공극균재증가，이점토적과립내공극、과립간공극화단립간공극각재감소。습간순배작용사점토체종대단립축점전화위소과립，병증대료토과립적철요성，분석SEM이치화도상득지토체공극솔균재증가；용압홍법화소묘전경법분석화해석토체개렬시가행적，소득적미관공극특정여굉관개렬규률기본상부。
This paper adopts cracking experiments and micro experiment observations of compacted clay specimens under the influence of different wetting-drying cycles.It investigates the effects of wetting-drying cycles on clay cracking and pore structure.Moreover it compares the experimental results of Mercury Intrusion Porosimetry(MIP) and Scanning Electron Microscopy (SEM)tests with those of the macro cracking experiments.The experimental results show that the wetting-drying cycles have a great influence on compacted clay cracking.The Cracking Intensity Factor (CIF ),representing the degree of compacted clay cracking, increases as moisture contents decrease,and is obviously larger than that before the wetting-drying cycles.As the number of wetting-drying cycles increases,the total volume of the pores,as the median pore diameter,the mean pore diameter,the mean porosity and the intra-aggregate pores increase.But the intra-particle pores,the inter-particle pores and the inter-aggregate pores reduce obviously.The wetting-drying cycles make the large aggregates of the clay gradually transform into small particles and increase the convexity of the soil particles.Besides,it is observed from the analysis of SEM binary image that the porosity increases with the wetting-drying cycles growing.It is plausible to employ Mercury Intrusion Porosimetry (MIP ) and Scanning Electron Microscopy (SEM)tests to analyze and explain the clay cracking.The micro pore characteristics derived from the tests are in line with the macro clay cracking law.
