高原冻土路基融沉问题及处置措施

Thawing Settlement of Plateau Permafrost Roadbed and Its Disposal Measures

冻土因其承载能力受温度影响大,被列为工程建设中的特殊土。随着公路和铁路修建到我国北部冬季严寒地区冻土逐渐被各界学者重视。本文依托G314线公路建设项目,首先对该路段冻土区的地温进行持续监测,得到该路段冻土的天然上限值为路面以下3.4m;进而结合该路段所处地区的气象条件、路基填料类型及性质、室内实验数据,通过对实验数据及现场观测数据的变化规律分析得出路肩及回填处土的温度随深度的增加而逐渐降低;进而对现场不同深度处的取样进行含水率实验,针对不同的土质及其含水量确定出路基的融沉等级;最后对高原冻土地区路基提出合理的防融沉处置措施:片块石路堤、热棒、通风管路堤,并针对各种措施给出了其防融沉的原理及优点。

Frozen soil is classified as special soil in engineering construction because its bearing capacity is greatly affected by ten^erature.With the construction of roads and railways to frozen soil in the cold winter regions of northern China,scholars from all walks of life gradually pay attention to it.Based on the highway construction project of G314 line,this paper firstly monitored the ground temperature of frozen soil area in this section continuously,and obtained that the natural upper limit of frozen soil in this section was 3.4m below the road surface.Combined with the meteorological conditions of the region where the section is located,the types and properties of subgrade filling,and the data of laboratory experimental,the variation law of the experimental data and the field observation data were analyzed,and the temperature of the outlet shoulder and the backfill soil decreases gradually with the increase of depth.Then the moisture content of samples at different depths of the site was tested and the grade of subgrade thawing settlement was determined according to different soil quality and water content.Finally,the reasonable anti-thawing settlement disposal measures are put forward for the roadbed in plateau frozen soil area,such as rock embankment,hot rod embankment and ventilation pipe embankment,and the principle and advantages of different anti-thawing settlement measures are given.