基于MIP和CT试验的钙质砂孔隙分布特征研究
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摘要
钙质砂是一种以碳酸钙为主要成分的岩土介质,含有丰富的内孔隙。内孔隙的存在,对钙质砂宏观力学性质具有重要影响。为了研究钙质砂的微观孔隙结构特征,选取南海某岛礁建设地基的钙质砂试样,根据粒径大小将其分为4个不同的粒组,联合使用MIP压汞试验和CT扫描试验,对不同粒径钙质砂的微观孔隙性状进行了定量表征。结果表明:钙质砂孔隙分布特征曲线表现出双峰特征,小孔隙的体积占比最大,约为50%左右,其次是大孔隙,而微孔隙的含量则很少。随着粒径的增大,钙质砂的孔隙率也在不断增大,但增大的幅度逐渐减小。钙质砂的封闭内孔隙率约在1%上下浮动,远低于连通孔隙率。
With calcium carbonate as a main component, calcareous sand is a kind of geotechnical medium which is rich in inner pore. It has great effects on macroscopic mechanical properties. In order to analyze the characteristics of micro pore of calcareous sand, testing samples from South China Sea are divided into four groups according to grain size. A series of mercury injection porosimetry and CT scan tests are conducted to obtain the microscopic pore characteristics of calcareous sand. Based on the results, a bimodal pattern of the pore distribution curves is observed, which indicate that two main distribution intervals are involved in the inner pores. The pores of small size have the largest proportion which is about 50%, followed by the pores of large size, and the last was the micro pores. The porosity of calcareous sand increases with grain size, but gradient show a decreasing tendency. The closed porosity of calcareous sand is about 1%, which is much lower than connected porosity.
With calcium carbonate as a main component, calcareous sand is a kind of geotechnical medium which is rich in inner pore. It has great effects on macroscopic mechanical properties. In order to analyze the characteristics of micro pore of calcareous sand, testing samples from South China Sea are divided into four groups according to grain size. A series of mercury injection porosimetry and CT scan tests are conducted to obtain the microscopic pore characteristics of calcareous sand. Based on the results, a bimodal pattern of the pore distribution curves is observed, which indicate that two main distribution intervals are involved in the inner pores. The pores of small size have the largest proportion which is about 50%, followed by the pores of large size, and the last was the micro pores. The porosity of calcareous sand increases with grain size, but gradient show a decreasing tendency. The closed porosity of calcareous sand is about 1%, which is much lower than connected porosity.
引文
[1] 洪保宁,刘鑫.土体微细观结构理论与试验[M].北京:科学出版社,2010:1-10.
[2] 周健,贾敏才.土工细观模型试验与数值模拟[M].北京:科学出版社,2008:7-13.
[3] 王艳丽,程展林.CT扫描技术在我国土工试验中的应用研究进展[J].地震工程学报,2015,37(S1):35-39.
[4] 虞海珍,汪稔.钙质砂动强度试验研究[J].岩土力学,1999,20(4):6-11.
[5] 孙吉主,黄明利,汪稔.内孔隙与各向异性对钙质砂液化特性的影响[J].岩土力学,2002,23(2):166-169.
[6] 陈海洋.钙质砂的内孔隙研究[D].武汉:中国科学院武汉岩土力学研究所,2005:46-50.
[7] Lapierre C,Leroueil S,Locat J.Mercury intrusion and permeability of Louiseville clay[J].Canadian Geotechnical Journal,1990,27(6):761-773.
[8] 唐益群,赵书凯,杨坪,等.饱和软黏土在地铁荷载作用下微结构定量化研究[J].土木工程学报,2009,42(8):98-103.
[9] 张先伟,孔令伟,郭爱国,等.不同固结压力下强结构性黏土孔隙分布试验研究[J].岩土力学,2014,35(10):2794-2800.
[10] Dal Ferro N,Delmas P,Duwig C,et al.Coupling X-ray microtomography and mercury intrusion porosimetry to quantify aggregate structures of a cambisol under different fertilisation treatments[J].Soil & Tillage Research,2012,119:13-21.
[11] Yang B H,Wu A X,Guillermo A N,et al.Use of high-resolution X-ray computed tomography and 3D image analysis to quantify mineral dissemination and pore space in oxide copper ore particles[J].International Journal of Minerals Metallurgy and Materials,2017,24(9):965-973.
[12] 王旭东,田威,王昕.基于CT技术的混凝土细观三维重建研究[J].水利与建筑工程学报,2014,12(3):94-97.
[13] 朱长歧,陈海洋,孟庆山,等.钙质砂颗粒内孔隙的结构特征分析[J].岩土力学,2014,35(7):1831-1836.
[14] Zhu C,Wang X,Wang R,et al.Experimental microscopic study of inner pores of calcareous sand[J].Material Research Innovations,2014,18(S2):207-214.
[15] 蒋明镜,吴迪,曹培,等.基于SEM图片的钙质砂连通孔隙分析[J].岩土工程学报,2017,39(S1):1-5.
[16] 吕海波,汪稔,孔令伟.钙质土破碎原因的细观分析初探[J].岩石力学与工程学报,2001,20(S1):890-982.
[17] 李建胜,王东,康天合.基于显微CT试验的岩石孔隙结构算法研究[J].岩土工程学报,2010,32(11):1703-1708.
[18] 朱国平,陈正汉,韦昌富,等.浅层红黏土的细观结构演化规律研究[J].水利与建筑工程学报,2016,14(4):42-49.
[19] 邓远刚,王述红,孟嫣然,等.基于CT扫描的致密砂岩脆性破坏裂纹扩展规律研究[J].水利与建筑工程学报,2017,15(4):39-43.
[20] 李德成,Velde B,Delerue J F,等.孔隙结构图像分析中不同试验因素对分析结果的影响[J].土壤学报,2002,39(1):52-57.
[21] 王清,王剑平.土孔隙的分形几何研究[J].岩土工程学报,2000,22(4):496-498.
[2] 周健,贾敏才.土工细观模型试验与数值模拟[M].北京:科学出版社,2008:7-13.
[3] 王艳丽,程展林.CT扫描技术在我国土工试验中的应用研究进展[J].地震工程学报,2015,37(S1):35-39.
[4] 虞海珍,汪稔.钙质砂动强度试验研究[J].岩土力学,1999,20(4):6-11.
[5] 孙吉主,黄明利,汪稔.内孔隙与各向异性对钙质砂液化特性的影响[J].岩土力学,2002,23(2):166-169.
[6] 陈海洋.钙质砂的内孔隙研究[D].武汉:中国科学院武汉岩土力学研究所,2005:46-50.
[7] Lapierre C,Leroueil S,Locat J.Mercury intrusion and permeability of Louiseville clay[J].Canadian Geotechnical Journal,1990,27(6):761-773.
[8] 唐益群,赵书凯,杨坪,等.饱和软黏土在地铁荷载作用下微结构定量化研究[J].土木工程学报,2009,42(8):98-103.
[9] 张先伟,孔令伟,郭爱国,等.不同固结压力下强结构性黏土孔隙分布试验研究[J].岩土力学,2014,35(10):2794-2800.
[10] Dal Ferro N,Delmas P,Duwig C,et al.Coupling X-ray microtomography and mercury intrusion porosimetry to quantify aggregate structures of a cambisol under different fertilisation treatments[J].Soil & Tillage Research,2012,119:13-21.
[11] Yang B H,Wu A X,Guillermo A N,et al.Use of high-resolution X-ray computed tomography and 3D image analysis to quantify mineral dissemination and pore space in oxide copper ore particles[J].International Journal of Minerals Metallurgy and Materials,2017,24(9):965-973.
[12] 王旭东,田威,王昕.基于CT技术的混凝土细观三维重建研究[J].水利与建筑工程学报,2014,12(3):94-97.
[13] 朱长歧,陈海洋,孟庆山,等.钙质砂颗粒内孔隙的结构特征分析[J].岩土力学,2014,35(7):1831-1836.
[14] Zhu C,Wang X,Wang R,et al.Experimental microscopic study of inner pores of calcareous sand[J].Material Research Innovations,2014,18(S2):207-214.
[15] 蒋明镜,吴迪,曹培,等.基于SEM图片的钙质砂连通孔隙分析[J].岩土工程学报,2017,39(S1):1-5.
[16] 吕海波,汪稔,孔令伟.钙质土破碎原因的细观分析初探[J].岩石力学与工程学报,2001,20(S1):890-982.
[17] 李建胜,王东,康天合.基于显微CT试验的岩石孔隙结构算法研究[J].岩土工程学报,2010,32(11):1703-1708.
[18] 朱国平,陈正汉,韦昌富,等.浅层红黏土的细观结构演化规律研究[J].水利与建筑工程学报,2016,14(4):42-49.
[19] 邓远刚,王述红,孟嫣然,等.基于CT扫描的致密砂岩脆性破坏裂纹扩展规律研究[J].水利与建筑工程学报,2017,15(4):39-43.
[20] 李德成,Velde B,Delerue J F,等.孔隙结构图像分析中不同试验因素对分析结果的影响[J].土壤学报,2002,39(1):52-57.
[21] 王清,王剑平.土孔隙的分形几何研究[J].岩土工程学报,2000,22(4):496-498.