兰州高坪马兰黄土工程性质规律初探  

Study on Engineering Properties of the Late Pleistocene Epoch Loess on High Fluvial Terrace in Lanzhou

作　　者：米海珍[1] 胡燕妮[1] 

机构地区：[1]兰州理工大学,兰州730050

出　　处：《建筑科学》2008年第11期79-82,共4页Building Science

基　　金：甘肃省自然科学基金(3ZS042-B25-031)

摘　　要：兰州高坪马兰黄土分布广泛，湿陷厚度大，工程处理困难。通过对兰州地区（陇西黄土区）两处高坪7个不同位置处黄土工程性质的测试及分析，对此有一些新的认识：高坪黄土的湿陷深度在20m左右，湿陷系数随干密度呈指数变化δs=10．53pd^20，10m以浅湿陷性变化剧烈，10～20m的湿陷性轻微，20m以深湿陷性基本消失；黄土的初始孔隙比与湿陷后孔隙比存在明显的分界线，界线孔隙比是0．90，湿陷性黄土初始孔隙比与干密度满足的关系是：当e0〉0．9时，Pd＋0．6325e0-1．972≥0。The late Pleistocene Epoch loess is deposited on high fluvial terrace of Lanzhou, which develops widely and appears very thick collapsible layer, it is difficult to cope with collapsibility in engineering. To test and analyze engineering properties some samples were taken at 7 sites on two high fluvial terraces. According to soil test results some new viewpoints are obtained with the loess. The maximum collapsible depth is about 20meters. Dry density Pd is exponent correlated with coefficient of collapsibility δs＋ δs = 10.53pd^-20. When the depth is in the scope of 0 - 10meters, the collapsibility changes greatly from maximum to minimum. While the depth is in the scope of 10- 20meters, the collapsibility is obviously slight. There is almost not any collapsibility when the depth is greater than 20meters. There is a void ratio limit at start and end of the collapsibility test. The void ratio limit is 0.90. Void ratio at start test e0 and dry density Pd are correlated for the collapsible loess：当 e0 〉 0.9 时,pd ＋ 0.6325% - 1.972≥0.

关 键 词：马兰黄土 湿陷系数 干密度 孔隙比 

分 类 号：TU444[建筑科学—岩土工程] P642.131[建筑科学—土工工程]