Abstract: Based on the gobi-filler test of testing for subgrade on the second double line of Lan-Xin Railway, the difference and relation between the ground coefficient K30 and the static modulus of deformation Ev2 were analyzed; and the curve feature of ground coefficient K30 and deformation modulus Ev of four different kinds of fillers were summed up; also, the correlation between K30 and Ev were analyzed. With more information of the laboratory test, the acting factors for K30 and Ev2 were summed up. The results show that: ① The compaction quality of the soil is the main factor for K30, Ev1 and Ev2/Ev1. ② The nature of the filler is the main acting factor for Ev2 and it also has a influence on Ev2/Ev1. ③ The Ev2 is the characteristic parameter for the filler; it reflect the rigidity of the subgrade. ④ The K30 is the controlling index for compaction quality. ⑤ The correlation between K30 and Ev1 is closer, while K30 and Ev2 is slight; and different kinds of fillers have different correlations between K30 and Ev; the results reveal that the correlation is little with the checking indices become more disperse.

Key words: gobi area filler, high-speed railway subgrade, ground coefficient, modulus of deformation