寒区高速公路路基填料冻胀特性的试验装置及方法

共和至玉树高速是我国在青藏高原多年冻土区修筑的第一条高速公路,建成后对于维护边疆地区的稳定和促进藏区的发展具有重要的意义。提高冻土区路基的稳定性是保证公路良好运营的最基本条件,以共玉高速公路多年冻土区路基填料为研究对象,通过现场调查和室内试验相结合的方法,根据填料冻胀特性要求,按照粒径大小确定出了路基填料的分类标准;总结出了适用于多年冻土区路基填料冻胀特性的试验方法;确定了最适宜的粗细填料冻胀特性试样高度;根据得出的路基填料冻胀试验的最小的试样几何尺寸数据,设计并试制出了用于测试路基细、粗填料冻胀试验制备试样的两类试模,同时在试验中引入压实度的因素使试验与实际更为吻合,解决了现阶段无法解决的冻土区填料冻胀试验的难题,为以后开展路基填料冻胀特性试验研究工作提供了依据。

Test Device and Method for Frost Heave Characteristics of Subgrade Filling of Freeway in Cold Regions

Gonghe-Yushu Expressway is the first expressway constructed in permafrost region of Qinghai-Tibet Plateau in China.It is also of great significance to maintain the stability of frontier areas and promote the development of Tibetan areas.Improving the stability of roadbed in permafrost area is the most basic condition to ensure the good operation of Expressway.This paper takes the roadbed filling in permafrost area of Gongyu Expressway as the research object.The classification standard of roadbed filling is determined according to the size of particle size according to the requirement of the freezing-heave characteristics.The test methods of frost heave characteristics are determined,and the optimum height of frost heave characteristics of coarse and fine fillings is determined.According to the minimum sample size data obtained from frost heave tests of roadbed fillings,two kinds of test models are designed and manufactured to test the frost heave characteristics of fine and coarse fillings of roadbed.At the same time,the compactness factor is introduced into the test to make the test more consistent with the reality and solve the problem.At present,the difficult problem of frost heave test of fillers in frozen soil area can not be solved,which provides a basis for future research on frost heave characteristics of subgrade fillers.