兰新客运专线浩门区间路基温度、水分及冻胀变形特征

Characteristics of subgrade's temperature,moisture and frost heave deformation in Haomen,passenger railway line from Lanzhou to Xinjiang

粗细颗粒混合填料的微冻胀严重影响着寒冷地区高速铁路的安全运营.基于对兰新客运专线浩门区间运营期4个路基断面不同深度的温度、水分及冻胀变形现场监测,分析了冻结期该铁路路基在不同深度下的温度、水分及冻胀随季节变化特征.结果表明:越接近地表,对外界环境温度变化的敏感性越高,温度传递随时间的滞后性呈指数递减规律,深度超过3 m时全年无负温.寒季2.7 m厚的路基最大冻胀量约2.1 cm,其中,0~0.5 m处寒季最低温度介于-10.3^-15.6℃,暖季及冻结初期含水量相对较高有15%左右,其冻胀率约4.86 mm·m-1,故级配碎石在低温含水量高情况下能有效减弱冻胀.冻胀率最大值(14.34 mm·m-1)发生在0.5~1.5 m之间的普通AB组填料层,寒季最低温度介于-7.2^-12.4℃,暖季及冻结初期含水量介于10%~15%.1.5~2.7 m之间的填料层冻胀率约为1.94 mm·m-1,寒季最低气温-3.2~0.4℃,暖季及冻结初期含水量介于12.5%~15%.路基填料细颗粒(粒径小于0.25 mm)含量越高,冻胀率越大,建议将细颗粒料控制在15%以内.

The safe operation in high-speed railway in cold regions are effected by feeble frost heave of subgrade＇carrier with coarse particle and fine particle. Study the characteristics of temperature,moisture and frost heave deformation in different deep of subgrade,based on the 4 fracture surface where installing thermometers,moisture meter and frost heave instrument in different deep of subgrade in Haomen belong to the second line of Lanzhou-Xinjiang railway. The results showthat the more sensitive of temperature the more close to the earth＇ s surface,and there is no minus temperature under surface 3 m. The maximum value of frost-heave is 2. 1 cm above 2. 7 m layer. The deep of 0- 0. 5 m during the cold season the lowest temperature varies from- 10. 3 ℃to- 15. 6 ℃. During warm and initial freezing period,the water content is relatively higher can be reach to15%,frost heaving ratio is about 4. 86 mm ·m^- 1,so grading macadam under the condition of high moisture content and lowtemperature can effectively weaken the frost heave. The maximum rate of frost heave（ 14. 34 mm ·m^- 1） occurs between 0. 5- 1. 5 m,which layer carrier is ordinary AB group. The lowest temperature varies from- 7. 2 ℃ to- 12. 4 ℃ in cold season. During warm and initial freezing period,the water content is between 10% and 15%. Between the deep of 1. 5- 2. 7 m layer the frost heaving ratio is about 1. 94 mm ·m^- 1,the lowest temperature varies from- 3. 2 ℃ to 0. 4 ℃ in cold season. During warm and initial freezing period,the water content is between 12. 5% and 15%. The higher content of fine particle the more higher of the frost heaving ratio. Therefore the content of fine particles should be control under 15%.