石灰与水泥改性加固膨胀土对比试验研究  

Comparative study on lime and modified cement expansive soil

作　　者：黄启友 HUANG Qiyou(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《水利水电快报》2024年第3期54-60,共7页Express Water Resources & Hydropower Information

基　　金：中国铁建股份有限公司科技研发计划项目“数字化融合勘察设计一体化成套技术研究与应用”(2022-A02)。

摘　　要：为探究石灰和水泥改性两种方法加固膨胀土的效果,以蒙-华铁路三荆段为例,采用现场采样和室内试验,对膨胀土样品的颗粒分布和力学特性进行了分析,研究了两种改性加固方法不同掺和比例的加固效果,分析内摩擦角、黏聚力、剪切强度等指标的变化规律,对两种加固方案的效果进行了比较,并通过电镜扫描分析了加固后的微观结构,揭示加固机理。结果表明:MHTJ-19和MHTJ-21两个区段的膨胀土在黏性矿物成分、颗粒级配和力学参数方面一致性良好,不存在系统差异。石灰和水泥改性显著提升了膨胀土的黏聚力、内摩擦角和抗剪强度,其中水泥改性效果更佳。电镜扫描图像分析显示,这两种改性方法通过颗粒凝聚作用提高了膨胀土的力学性能和降低了膨胀性。研究成果可为重载铁路工程路基设计和维护提供参考依据。In order to study the effect of lime and cement soil modification on expansive soil,taking Sanjing section of Meng-Hua railway as an example,the particle distribution and mechanical properties of expansive soil samples were analyzed by field sampling and laboratory tests.The effects of two kinds of modified reinforcement methods with different blending ratios were studied,and the variation of internal friction angle,cohesion and shear strength were analyzed.Moreover,the micro-structure of the reinforced concrete was analyzed by SEM,and the mechanism of the reinforced concrete was revealed.The results showed that the consistency of clay mineral composition,particle size distribution and mechanical parameters of expansive soils in sections MHTJ-19 and MHTJ-21 were good,and there was no systematic difference.The cohesion,internal friction angle and shear strength of expansive soil were improved by lime and cement soil modification,but the effect of cement modification was better.The analysis of SEM images showed that the mechanical properties of expansive soil were improved and the swelling property was reduced by both methods through particle agglomeration.The research results can provide a reference for the design and maintenance of roadbed of heavy-haul railway engineering.

关 键 词：膨胀土 力学特性 石灰改性 水泥改性 

分 类 号：U213.15[交通运输工程—道路与铁道工程]