银西高铁甘宁段水泥改良黄土路基冻胀规律及冻胀防治效果评价  

The Frost Heave Law of Cement-improved Loess as Filling Material for Subgrade and Evaluation of Anti-frost Effect in Gansu-Ningxia Section of Yinchuan-Xi'an High-speed Railway

作　　者：江涛[1] JIANG Tao(China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an710043,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《铁道标准设计》2021年第9期8-17,共10页Railway Standard Design

摘　　要：银西高铁甘宁段属于寒冷地区,为防止路基填料的冻胀变形对轨道平顺性产生影响,按照甘宁段不同路基结构形式并结合地下水发育情况对路基进行长时间、全段落观测,通过人工及自动监测方式,掌握路基冻胀的具体变化情况,并对观测数据进行分析和研究。研究表明:银西线甘宁段路基总体冻胀有限,处于冻胀可控状态;路基冻胀主要发生在挖方和低填段落;路基冻胀残留值较小,路基本体经过冻融循环后基本恢复到冻结前的水平;对在建高铁项目水泥改良黄土的冻胀特性进行分析研究,水泥改良黄土填料冻胀值较小,未观测到明显冻胀;水泥改良黄土路基冻胀主要发生在基床表层,需重点做好基床表层的防冻胀设计;通过冻胀监测分析,银西高铁甘宁段冻胀原因主要是现场汇水或排水不畅。The Gansu-Ningxia Section of the Yinchuan-Xi'an High-speed Railway is located in a cold area,long-term and full-section observations of the subgrade are carried out according to the various subgrade structure forms and the distribution situation of groundwater to prevent the frost heave deformation of the subgrade from affecting the smoothness of the track.Meanwhile grasping the specific frost heave changes of subgrade and studying the observation data through the manual and automatic monitoring.Research shows that the overall frost heave of subgrade in the Gansu-Ningxia section of the Yinchuan-Xi'an High-speed Railway is limited,and the frost heave is in a controllable state.the frost heave of the Gansu-Ningxia section of the Yinchuan-Xi'an High-speed Railway mainly occurs in the excavation and low filling sections.the residual value of frost heave of subgrade is limit and the subgrade is basically returns to the level of unfrozen after the freeze-thaw cycle.It analyzes and studies the frost heave characteristics of cement-improved loess in the high-speed railway project under construction,the frost heave value of the cement improved soil is small,which is no significant frost heave observed.It is necessary to doing well the anti-frost heave design of surface layer of subgrade bed due to frost heave mainly occurs on surface layer of subgrade bed.Through frost heave monitoring and analysis,the main cause of frost heave in the Gansu-Ningxia section of the Yinchuan-Xi'an high-speed railway is water collection on site or poor drainage.

关 键 词：高速铁路 路基 水泥改良黄土 冻胀分析 人工监测 自动监测 冻胀规律 防治效果 评价 

分 类 号：U213.1[交通运输工程—道路与铁道工程] U238