青海省盐渍土区公路路基拓宽溶陷变形控制关键技术研究  

Research on Key Technology of Dissolution Deformation Control of Highway Subgrade Widening Construction in Saline Soil Area of Qinghai Province

作　　者：许正璇 XU Zhengxuan(Qinghai Transportation Planning and Design Research Institute Co.,Ltd.,Xining,Qinghai 810000,China)

机构地区：[1]青海省交通规划设计研究院有限公司,青海西宁810000

出　　处：《公路工程》2022年第4期117-123,共7页Highway Engineering

基　　金：青海省交通科技项目(2018-SF-139)。

摘　　要：以青海省某穿越盐渍土区公路的线路路基拓宽建设为例,对盐渍土进行了不同含盐量、压实度、上覆压力下的溶陷变形试验,分析了溶陷变形的影响因素,并根据高地下水位盐渍土区的防溶陷需求探讨了线路阻水的措施,最终建立了试验段进行阻水方案效果的论证。研究表明,随着压实度的增大溶陷系数减小,当压实度增加到0.93左右时,溶陷变形基本趋于稳定,压实度再增加,溶陷系数变化幅度也不大,根据防溶陷需求推荐采用砂砾换填+复合土工膜的方案来进行路基阻水;根据3个多月的观测,试验段路基差异沉降控制在10 mm左右,远小于非试验路段,说明在进行阻水设计后,盐渍土拓宽线路路基的整体性和水稳性较好。研究可为干旱与半干旱地区的盐渍土地区公路路基拓宽设计和施工提供参考。Based on a widening construction of highwaysubgrade crossing saline soil area at Qinghai Province,this paper carried out dissolution deformation tests of saline soil under different salt contents,compactness and overburden pressures,and the influencing factors of dissolution deformation were analyzed.In addition,the water resistance measures of the highway line with high groundwater level was discussed for.Finally,a test section was established for demonstration of preventing dissolution deformation effect.The results show that with the increase of compactness,the dissolution deformation coefficient decreases.When the compactness increases beyond 0.93,the dissolution deformation basically tends to be stable.Even if the compactness increases continually,the change rangeis not large.It is recommended to adopt the scheme of composite geomembrane+change filling for water resistance measure.According to the observation for more than three months,the subgrade differential settlement in the test section is about 10 mm,which is much smaller than that of ordinary subgrade.It is indicated that after water resistance design,the integrity and water stability of the widening line enhances.The study conclusion can be used as the reference on the design and construction of subgradewidening at saline soil area of arid and semiarid regions.

关 键 词：公路线路 盐渍土 路基拓宽 溶陷系数 阻水 复合土工膜 

分 类 号：U416.1[交通运输工程—道路与铁道工程]