지반 물성값에 따른 항타 진동이 지중 삼중관에 미치는 거동 분석

초록

In this study, the behavior of underground pipeline subjected to pile driving is examined using the verified finite element model based on the field experiment. Young``s modules of surface soil is varied and elastic modulus of the other soil layer is fixed. The pile driving force model proposed by Mounir E. Mabsout in 1999 was used and it was functions of time and of force. The forcing function applied on this study considers the kinetic energy of ram located at 1.2m height with 7 tonf. The 3-layered pipeline is composed of steel(inner) pipe, PUR(Polyurethane Resin, filler) and HDPE(outer) pipe, and the length/diameter of main steel pipe is 20m/0.8m(O.D). It is used for district heating pipes in Korea. The results are expressed in terms of Von Mises stress, displacement, and vibration velocity for each soil condition. From the results of the analyses , PUR which is originally intended as a thermal insulation of inner pipe shows performance as a structural member which distributes external pressure.

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