贵南高铁南宁段古近系泥岩膨胀性判别指标适用性分析  

Suitability of the Expansion Index for Paleogene Mudstone in Nanning Section of Guinan High-speed Railway

作　　者：布强 张磊 庞维福[2] 董斌 孙合金 Bu Qiang;Zhang Lei;Pang Weifu;Dong Bin;Sun Hejin(China Railway First Group Third Engineering,Baoji 721006,Shaanxi,China;Shaanxi Railway Institute,Weinan 714000,Shaanxi,China)

机构地区：[1]中铁一局集团有限公司第三工程分公司,陕西宝鸡721006 [2]陕西铁路工程职业技术学院,陕西渭南714000

出　　处：《岩土工程技术》2024年第2期226-232,共7页Geotechnical Engineering Technique

基　　金：中国铁路南宁局集团有限公司重点课题(2020B-003)。

摘　　要：贵南高铁南宁段古近系泥岩是湖沼沉积型半成泥岩,易遇水软化,失水崩解,有一定胀缩性。依托贵南高铁南宁段泥岩样品膨胀性试验数据及路堑边坡人字型骨架开裂的实际现象,采用了相关性、线性回归、匹配度等分析方法,对膨胀性判别指标适用性进行了研究。研究结果表明,干燥饱和吸水率单指标膨胀潜势分级结果与实际较接近,天然湿度样品的膨胀力、交换阳离子含量、蒙脱石含量及自由膨胀率等单指标膨胀潜势分级结果易下降1–2个等级。Paleogene mudstone in the Nanning section of the Guinan high-speed railway is a semi-formed mudstone deposited in lakes and marshes,which is easy to soften when it meets water or to disintegrate when it loses water and has certain swelling and shrinking properties.Based on the expansive test data of mudstone samples in the Nanning section of the Guinan high-speed railway and the actual phenomenon of herringbone skeleton cracking on cutting slope,the applicability of expansive discrimination indexes was studied by using analysis methods of correlation,linear regression,and matching degree.The results show that the grading results of single-index expansion potential by dry-saturated water absorption rate is close to the actual situation,and the grading results of singleindex expansion potential of natural humidity samples by expansion force,cation exchange capacity,montmorillonite content or free expansion rate are easy to drop by 1-2 grades.

关 键 词：古近系半成泥岩 干燥饱和吸水率 自由膨胀率 膨胀潜势 判别指标 

分 类 号：P642[天文地球—工程地质学]