内昆铁路李子沟“斜坡软土”特性及路基工程对策  

THE CHARACTER ISTICS OF CLNOTHEM AND RELEVANT ENGINEERING TREATMENT AT LIZIGOU OF NEIJIANG-KUNMING RAILWAY LINE

作　　者：魏永幸[1] 

机构地区：[1]铁道部第二勘测设计院地路处,成都610031

出　　处：《地质灾害与环境保护》2000年第2期104-106,共3页Journal of Geological Hazards and Environment Preservation

摘　　要：内昆铁路老锅厂至李子沟段的斜坡、台地 ,以及局部洼地、沟谷之下 ,不连续分布软土 ,被称为“斜坡软土”。黑色地层岩性软 ,遇水易软化 ,特殊的富水条件是形成李子沟“斜坡软土”的根本原因。其天然含水量小于液限或接近液限 ;有机质含量较高 ,一般在 4%～ 10 % ,个别可达 2 1%～ 3 1% ;空隙比较大 ,一般 e=1.0～ 1.5 ,个别可达 3 .0 92 ;天然快剪强度较高 ,一般 C=10～ 2 0 k Pa,最高可达 3 1.2 k Pa,φ=5°～ 12°;压缩性较高 ,压缩系数 a=0 .5 2～ 1.2 MPa- 1 ,个别达 2 .67MPa- 1。其分布具有不均匀性 ,平面范围和厚度均不连续 ;软土厚度变化大 ;物质成分复杂。李子沟“斜坡软土”还具有流滑性 ,多见斜坡浅层土体蠕滑现象。铁路选线应尽量避免以路堑通过 ,如以路堑通过 ,则必须采取先加固后开挖的措施 ;因软土底部具有一定横向坡度 ,路堤除对地基进行加固外 ,还需采取侧向约束措施。In the section from Laoguochang to Lizigou by Neijiang-Kunming Railway line,the softsoil distributes discontinuously under the surfaces of the slopes,mesa,local depressions and ravines which is known as ‘Clinothem-softsoil’.The cause produces ‘Clinothem-softsoil’ at Lizigou is that the lithological characters of black stratum in this area is soft,which will be softened when meeting the water, as this area is rich in water.In the soil in this area,the natural water content is smaller than or near the liquid limit;the organic matter content is high,generally being 4%～10%and specially being 21%～31%,relalively high,with the void ratio is ‘ C ’being 1.0～1.5 in general and 3.092 in special;the quick shear strength is strong,with ‘ C ’being 10～20 kPa,and the maxal ‘ e ’31.2 kPa,‘ φ ’ being 5～12 degree;the compression character is high,with compressibility factor ‘ a ’ being 0.52～1.2 MPa -1 in general and 2.67 MPa -1 in special.The distribution of the ‘Clinothemsoftsoil’ is inhomogeneous, and discontinuous and varies largely thickness. Its material composition is complex.The ‘Clinothemsoftsoil’ at Lizigou is of fluidsliding character, often observed in shallow soil creepingsliding on slope.When a railway is to be built in similar geological condition,the cutting should be avoided, or if the cutting is necessary,the stabilizing measures should be taken before cutting.As the soft soil base slopes traversely,the base should be stabilized,as well as the lateral restraint measures should be taken.

关 键 词：斜坡软土 流滑性 侧向约束 路基工程 对策 铁路 

分 类 号：P642.133[天文地球—工程地质学] U213.1[天文地球—地质矿产勘探]