季节性冻土地区客专路基现场试验

Field Test of Subgrade for Passenger Dedicated Line in Seasonal Frozen Regions

鉴于哈尔滨-大连(哈大)客专路基设计工后沉降不大于15 mm的要求,开展了路基现场试验.对路基中的温度、沉降变形及冻胀力的变化情况进行观测.结论表明:线路所处地区,10月下旬开始冻结,来年2月后地表附近地温过程线开始上抬;冻结层直到4月中旬才全部处于正温,最大冻深约为1.66 m,应做好防治措施.经过观测,路基在经历冻融循环后的沉降变形为10 mm左右,满足设计的要求.路基填料含水量应严格保持为最优含水量,并做好防排水措施,季冻区的路基将不会产生冻胀变形和冻胀力.

The settlement of subgrade for the Passenger Dedicated Line from Haerbin to Dalian is designed to be less than 15 ram; it is a very strict standard. The line is constructed in seasonal frozen regions; the subgrade is easy to deform after cycle of freezing and thawing. So it is very hard to construct. A field test of subgrade was operated in the Passenger Dedicate Line from Haerbin to Dalian. The soil temperature, settlement and soil pressure were measured. From the results, at the test place, the surface temperature of subgrade was under 0 ℃ in late October, and was higher than 0 ℃ in the next February. The frozen layer did not thaw until the middle of April. The maximum frozen depth was about 1.66 m. So it is necessary to take effective measure to prevent frost in this depth. Based on the field test data, the settlement of the subgrade was less than 10 mm, which is within the range of the design standard. If the water content of the subgrade material is maintained in optimum water content, and the drainage measure is effective, the subgrade will be unable to have frost-heave deformation and force.