注盐法整治季节性铁路路基冻害可行性试验研究

Feasibility Test Investigation on Remediation of Railway Roadbed Seasonal Frost Damage by Salt Injection Method

以青藏铁路鸟岛段季节性冻土区路基冻害为研究背景,在室内填筑路基实体模型,进行封闭系统中反复冻融循环条件下的模型试验,分析冻融循环条件下普通路基和注盐路基的温度和位移规律。结果表明:随着环境温度的周期性变化,普通段和注盐段的温度均呈现出正弦曲线变化规律,试验段温度波动范围为环境波动范围的1/3左右;普通段两个断面路基土体在固结沉降过程中呈现出有规律的抬升和下沉,注盐段呈缓慢下沉;普通段和注盐段两个试验段四个断面路基土体冻胀最大值分别为0. 23 mm、0. 10 mm和0. 06 mm、0. 05 mm,注盐之后路基冻胀减小平均约74%,说明注盐对于路基土体冻胀有很大的抑制的作用,注盐法整治路基冻害是可行的。

Taking the frozen injury of railway subgrade around seasonal frozen soil area of Bird Island Section of Qinghai-Tibet railway,we have carried out model test under the recurrent freeze-thaw cycles in closed systems and analyzed Temperature and displacement regularity of common subgrade and salt injection subgrade under the condition of freeze-thaw cycle by using method of filling subgrade entity model indoors. The results show that with the periodic variation of ambient temperature,the temperature of common section and salt injection section all presented sinusoidal charge rules and the temperature fluctuation range of test section is about one third of the of environment;two of sectional subgrades in common section presented regular upthrow and subsidence in the process of consolidation and settlement which in salt injection presented slow subsidence;the maximum frost heave of four sectional subgrades soil in two test sections,common section and salt injection section,is 0. 23 mm,0. 10 mm,0. 06 mm and 0. 05 mm respectively,and the frost heave of subgrade decreases by an average of 74%,which is concluded that salt injection has a great restraining effect on frost heave of roadbed soil,and it is feasible to treat roadbed frost damage by salt injecting.