Contrastive Study on Permeability Characteristics of Angolan Red Sand and Chinese Malan Loess
-
摘要: 通过室内变水头渗透试验和现场双环注水试验,测试了安哥拉罗安达红砂的渗透系数。基于试验结果并参考相关文献,对比分析了安哥拉红砂与中国马兰黄土的渗透特性。结果表明,室内试验测得的天然红砂渗透系数为现场试验测试结果的1/8,室内试验测得的压实红砂渗透系数与现场试验测试结果相近。红砂渗透系数的对数与孔隙比正相关,随孔隙比增加而线性增加,工程建设中可按孔隙比估算红砂渗透系数。天然状态下红砂渗透系数约为马兰黄土渗透系数的10倍,且现场试验结果均大于室内试验结果。红砂和马兰黄土均存在水平入渗和竖直入渗,但红砂的入渗距离大于马兰黄土。红砂入渗过程主要为非饱和渗透,而马兰黄土入渗过程主要为饱和渗透。研究结果可为红砂地区工程建设提供参考。Abstract: The permeability coefficients of Luanda red sand in Angola is measured by laboratory variable head permeability test and double-ring water infiltration test. Based on the test data and references, the permeability characteristics of Angola red sand and Chinese Malan loess were compared and analyzed. The results show that the permeability coefficient of natural red sand in laboratory test is 1/8 of that in field test, and the permeability coefficient of compacted red sand in laboratory test is close to that in field test. The logarithm of the permeability coefficient of red sand is positively correlated with the void ratio, and increases linearly with the increase of void ratio. The permeability coefficient of red sand can be estimated according to the void ratio in engineering construction. The permeability coefficient of red sand in natural state is about 10 times that of Malan loess, and the field test results are greater than the laboratory test results. Both red sand and Malan loess have horizontal infiltration and vertical infiltration, but the infiltration distance of red sand is larger than Malan loess. The infiltration process of red sand is mainly unsaturated, while that of Malan loess is mainly saturated. The research results can provide reference for engineering construction in red sand area.
-
Key words:
- Angolan /
- red sand /
- Malan loess /
- permeability coefficient
-
表 1 试验场地红砂的基本物理性质指标
指标名称 含水率
w/%干密度
ρd/(g·cm−3)饱和度
Sr/%孔隙比
e湿陷系数
δs自重湿陷
系数δzs最大值 8.6 1.79 41 0.734 0.051 0.038 最小值 3.7 1.54 12 0.492 0.003 0.001 平均值 5.9 1.66 26 0.608 0.020 0.014 -
[1] 刘争宏,廖燕宏,张玉守. 罗安达砂物理力学性质初探[J]. 岩土力学,2010,31(S1):121-126. doi: 10.3969/j.issn.1000-7598.2010.z1.020 [2] 彭友君,岳 栋,彭 博,等. 安哥拉格埃路砂地层的承载力研究[J]. 岩土力学,2014,35(S 2):332-337. [3] 于永堂,郑建国,刘争宏. 安哥拉Quelo 砂抗剪强度特性试验研究[J]. 岩土力学,2012,33(S1):136-140. [4] 刘争宏,于永堂,唐国艺,等. 安哥拉 Quelo砂场地渗透特性试验研究[J]. 岩土力学,2017,38(S2):177-182. [5] 高国瑞. 中国黄土的微结构[J]. 科学通报,1980,(20):945-948. [6] 雷祥义. 中国黄土的孔隙类型与湿陷性[J]. 中国科学(B辑),1987,(12):1309-1318. [7] 苗天德. 湿陷性黄土的变形机理与本构关系[J]. 岩土工程学报,1999,21(4):383-387. doi: 10.3321/j.issn:1000-4548.1999.04.001 [8] 张苏民,张 炜. 减湿和增湿时黄土的湿陷性[J]. 岩土工程学报,1992,14(1):57-61. doi: 10.3321/j.issn:1000-4548.1992.01.007 [9] 陈正汉,刘祖典. 黄土的湿陷变形机制[J]. 岩土工程学报,1986,8(2):1-12. doi: 10.3321/j.issn:1000-4548.1986.02.001 [10] 郑建国,张苏民. 黄土的湿陷起始压力和起始含水量[J]. 工程勘察,1989,(2):6-10. [11] GB/T 50123—1999 土工试验方法标准[S]. 北京: 中国计划出版社, 1999. [12] SL 345—2007 水利水电工程注水试验规程[S]. 北京: 中国水利水电出版社, 2007. [13] 王 辉,岳祖润,叶朝良. 原状黄土及重塑黄土渗透特性的试验研究[J]. 石家庄铁道学院学报(自然科学版),2009,22(2):20-22,31. [14] 杨仲康,陈 冠,孟兴民,等. 基于现场渗透试验的黄土滑坡体入渗特性[J]. 兰州大学学报(自然科学版),2017,53(3):285-291. [15] 杨 华. 裂隙性黄土渗透特性试验研究[D]. 西安: 长安大学, 2016.