同位素及水化学方法研究黏性土孔隙水的运动特征  

Isotope and Water Chemistry Method Research Movement Characteristics of the Pore Water in Cohesive Soil

作　　者：赵智[1] 王超[1] 陈建生[1] 

机构地区：[1]河海大学地球科学与工程学院,南京210098

出　　处：《科学技术与工程》2015年第2期27-33,38,共8页Science Technology and Engineering

基　　金：国家重点基础研究发展计划(973计划)项目(2012CB417005);国家自然科学基金项目(61301025)资助

摘　　要：为讨论黏性土中孔隙水的运动特征,运用水化学及氯、氦、氩同位素方法,通过分析主要阴阳离子（K＋、Na＋、Ca2＋、Mg2＋、Cl-、Br-等）、同位素37Cl和18O、D及惰性气体（He、3He/4He和36Ar/40Ar）与深度的变化特征来探讨黏性土中孔隙水的起源、水化学特征和孔隙水运动特征。发现研究区内（0~100）m孔隙水中Na＋,Cl-随深度增加而减小,但其变化速率逐渐变大,在78.8m处出现突变,最后平缓,表明孔隙水运移速率在垂向上先快后慢;而孔隙水中Cl-/Br-比值随深度呈明显的分带性：（16.2~37.7）m、（53.5~78.8）m两个深度段,Cl-/Br-比高达4 691.25或无穷大,体现出明显的淡水起源,（37.7~49.5）m时Cl-/Br-比为508.36~2 751.71,（88.4~97.1）m时Cl-/Br-比为277.50~288.25,孔隙水表现出海水起源的特征;在（16.2~68.2）m深度内,其δ37Cl（‰）变速速率也是逐渐加快,在（68.2~97.1）m内逐渐变慢,也表明孔隙水在该段的流速随着深度增加而加快,且Cl-沿着垂直方向上可能在不同程度富集35Cl;其3He/4He和36Ar/40Ar比值与大气中比值相似。The characteristics of the movement of the pore water in the cohesive soil was discussed by using wa- ter chemistry and chlorine, argon and helium isotope method, through the analysis of the relations of major anion and kation （K＋ ,Na＋ ,Ca2＋ ,Mg2＋ ,C1- ,Br- etc） and 37C1 and lSo isotope D and inert gas （3He/4He and 36Ar/40Ar） variation characteristics with depth to investigate the origin of the pore water in the cohesive soil, water chemical characteristics and characteristics of pore water movement. It is discovered that in the study area（0- 100） m the Na ＋ , C1- of pore water decreased with depth,but its rate of change increases gradually, at 78.8 m become muta- tion, finally smooth, which shows that pore water rate become fast first, then slow ; the C1 -/Br- ratio of pore water with depth is obvious a zoning：it has （16.2 ~37.7） m and （53.5 -78.8） m two depth segments, the C1-/Br ratio is as high as 4 691.25 or infinity, which reflects the clear fresh water origin, in （37.7 - 49.5） m the C1-/ Br ratio is 508.36 ~2 751.71, in （88.4 -97.1） m the C1-/Br- ratio is （277.50 -288.25）, which reflects the origin of the pore water meter in the water of the sea;within （16.2 ~ 68.2） m, the change rate of δ37 C1 （%v） is also gradually accelerated, within （68.2 ~ 97.1 ） m gradually become slow, also shows that the pore water rate increase with depth in its velocity, and C1- become enrichment of 35 C1 in different degree along the vertical direction; Its 3 He/4He and 36Ar/40Ar ratio is similar to the ratio in the atmosphere.

关 键 词：水化学 同位素 黏性土 运动特征 

分 类 号：P641.12[天文地球—地质矿产勘探]