南坪水库筑坝土料分散机理及原因分析  

Mechanism and reason of dispersivity of dam soil in Nanping Reservoir

作　　者：高明霞[1] 李鹏[1] 王国栋[2] 樊恒辉[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [2]西北农林科技大学理学院,陕西杨凌712100

出　　处：《岩土工程学报》2009年第8期1303-1308,共6页Chinese Journal of Geotechnical Engineering

基　　金：西北农林科技大学青年学术骨干项目(08);西北农林科技大学科研专项(06ZR41)

摘　　要：利用双比重计、针孔、碎块、孔隙水可溶盐阳离子和原土交换性钠百分比5种试验方法对南坪水库土样进行了分散性鉴定,进一步结合物理化学性质和矿物成分分析,研究了土料的分散机理及原因。试验结果表明:K16和K19属于非分散性土,而K30和Z10属于分散性土。碱性环境下,蒙脱石和钠离子较多是土壤产生分散性的主要原因;土壤的颗粒组成是土壤产生分散的另一个主要原因。黏粒,尤其是胶粒的胶结作用,对土料的结构稳定性具有重要作用。土料的易溶盐中钙离子较多和有机质含量较高能有效抑制土料的分散性,掺入消石灰能有效改善土料的分散性。The dispersivity of dam soil samples in Nanping Reservoir is identified by means of double-hydrometer tests, pore water salt tests, pinhole tests, crumb tests and exchangeable sodium percent tests. Furthermore, the dispersive mechanism and reasons are also studied in combination with the analysis of physicochemical properties and mineral components. The results show that K16 and K19 are nondispersive, and K30 and Z10 are dispersive. Rich montmorillonoid and sodium-ion are the main reasons to cause the dispersivity of soil under the alkalic environment, and another key reason is the granulometric composition of soil. The cementation of clay, especially colloidal particle, plays an important role in the structural stability of soil samples. Much calcium ion and high organic matter can restrain the dispersivity of soil, and adding lime can improve it effectively.

关 键 词：分散性土 物理化学性质 分散机理 黏粒含量 

分 类 号：TV443[水利工程—水工结构工程]