Abstract: With the continuous improvement of the urban subway's ongoing construction and subway network, there are a growing number of new railway tunnels under through the existing railway lines. The normal operation the rail lines and the integrity of these existing structures should be warranted. This paper presents the results of using Type D Girder to reinforce the space of Guanhui intercity rail line underneath the existing BeijingKowloon Line. The site specific engineering soil properties were obtained from the site boring and testing program. The performance of the Type D Girder was simulated by using ANSYS finite element software. Two span lengths, 20 m and 24 m, under two different operation loading conditions of passenger train and cargo train, were analyzed. The numerical simulation results are compared with the construction monitoring results and the construction safety of the future safe operation of the intercity rail line tunnel underneath the existing rail line can be warranted.

Key words: Type D Girder, ANASYS Software, Finite Element Analysis, Underground Engineering