膨胀土裂缝灌浆效果可视化定量评价方法  

A Visual Quantitative Method for Evaluating the Effectiveness of Grouting Expansive Soil Cracks

作　　者：周学友 张敏 常兆广 翟晓平 丁浩桢 王新志[2,3] ZHOU Xue-you;ZHANG Min;CHANG Zhao-guang;ZHAI Xiao-ping;DING Hao-zhen;WANG Xin-zhi(Head Section Branch,Middle Route of China South-to-North Water Diversion Co.,Ltd.,Nanyang 473000,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;University of Chinese Academy ofSciences,Beijing 100049,China)

机构地区：[1]中国南水北调集团中线有限公司渠首分公司,河南南阳473000 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071 [3]中国科学院大学,北京100049

出　　处：《长江科学院院报》2023年第10期108-114,122,共8页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(41572297)。

摘　　要：膨胀土裂缝灌浆效果评价是工程界的一大难题。采用微米CT扫描对膨胀土试样裂缝的灌浆充填效果进行了定量评价和分析,提出采用整体孔隙率、逐层面孔隙率、孔隙等效直径与灌入指数等指标对膨胀土裂缝灌浆充填效果进行定量综合分析。采用超细水泥和膨胀土配置4种浆液对膨胀土裂缝进行灌浆试验,在灌浆前、后对试样进行CT扫描获取内部切片图像后再进行三维重建和后处理分析。采用整体孔隙率、逐层面孔隙率、孔隙等效直径和灌入指数定量分析了膨胀土裂缝灌浆效果和最小可灌入裂缝宽度。结果表明:浆液的可灌性随水固比增大而提高;灌入水固比为1.2的浆液可使膨胀土试样的整体孔隙率降低幅度可达到99%以上,其中超细水泥含量50%的浆液可灌入的最小裂缝宽度为0.6 mm。该方法可为定量评估各类浆液在膨胀土裂缝中的灌浆充填效果提供参考。Assessing the effectiveness of grouting expansive soil cracks presents a formidable challenge in the field of engineering.In this study,we employed micro-CT scanning technology to quantitatively evaluate the grout filling effect of cracks within expansive soil specimens.Slurries of ultra-fine cement and expansive soil with varied dosage was utilized to grout the cracks.CT scans were conducted before and after grouting to obtain internal slice images,which were then subjected to three-dimensional reconstruction and post-processing analysis.The grouting effect of expansive soil cracks and the minimum width of groutable cracks were quantitatively analyzed using overall porosity,layer-by-layer porosity,pore equivalent diameter,and groutable index.The results illustrated that the groutability of slurry improves with an increase in the water-solid ratio.A water-solid ratio of 1.2 can reduce the overall porosity of expansive soil samples by over 99%,and the minimum crack width for a slurry with an ultra-fine cement content of 50%is 0.6 mm.This method provides a reference for quantitatively evaluating the grouting and filling effects of various slurries in expansive soil cracks.

关 键 词：膨胀土 CT扫描 孔隙率 灌浆材料 裂缝 

分 类 号：TU443[建筑科学—岩土工程]