The Analysis And Prevention Measures To The Subgrade Of Seasonal Frozen Area Railway Line

In the seasonal frozen area,the freezing damage has always been the main problem of railway and highway subgrade,and it is the controlling factor that impact the specifications of railway and highway subgrade,also impact the vehicle stability。Based on the freezing damage of the railway subgrade which is in jilin province—a part of JingHa railway line,the heaving mechanism,influencing factor and preventive measures have been studied in this paper。The reasons for the concrete damage is analyzed,and the detailed prevention measures has been worked out,getting a good result. It includes 5 chapters。Part 3 and Part 4 are the hardcore of this paper。Chapter 1 is mainly introduce the problem of jingha railway subgrade—freezing damage and then introduce the development and research status of the forst heave in the seasonal frozen area。This chapter is also talking about the research purpose,study content,study method and the conclusion of the study.The second chapter is about the investgation and the causes of the damage in jingha railway subgrade。Started with investgation at the jilin part of JingHa railway line and field observation,it determined the main disease type of the subgrade is the frost heave,its performance is asymmetric heave in winter and mud pumping in spring.。According to the actual conditions of the frost heave,selective sampling test in two steps was taken。Through the interior routine experiment and original place probing,influencing factor to the soil heave has been carried out。First, the frost heave mechanism of the soil is studied and it work out the causes of heaving。Secondly,the influence of soil,water,temperature,load to the frost heave is mainly researched。The differences of the soil particle consist,saltness and soil density have a large impact to the soil frost heave。The Water content and the varaity in freezing soil decide the intensity of the soil;The freezing temperature is relative to the soil particles'disperse degree,water content,consist of the mineral substance and consist,concentration of aqueous solution;Raising outside load will restrain the heave obviously,at the despense of higher probability of other injury。In the view of conserving railway,the temperature and train load is unchangable and universal,however,the soil and water not。The third chapter is abou the test in jingha railway subgrade,and is the core in this paper。According to the actual conditions of the frost heave,selective sampling test in two steps was taken。Then through the routine test,heave test and orginal place probing, analysing the heave subgrade of JingHa railway line,it decided the causes of the heave:bad soil and higher water content which is caused by bad drainage system。The heave intensity in different water content and in the certain water content but different saltness is emphasis。The forth chapter is about another point of this paper which studied the prevention measures of the JingHa railway's subgrade disease。It elaborated the conventional prevention measures to subgrade disease,includes exchanging and filling,Physical chemistry,chemistry reinforcement,insulation,drainage and impermeable, building resistance raising,freeze-thaw deformation adaption ability—structure method, and analysised comparation among all kinds of approaches。Based on this,according to the specific condition of the JingHa railway subgrade disease,considering the geologic circurmstance and weather condition,the concrete measures have been worked out。 And then,tracing the line processed determined and evaluate the effect of it。Chapter 5 is the summary of the paper in which the study content and direction are also pointed out。...