일반적으로 지중구조물은 지상구조물보다 지진하중 작용 시 상대적으로 작은 영향을 받는다. 그러나 많은 연구자들은 심각한 지중구조물 손상에 대해 보고하고 있으며 동적 흙-구조물 상호작용에 대한 지속적인 연구를 수행하고 있다. 본 연구에서는 유한요소해석 프로그램을 활용한 흙-구조물 상호작용을 지중구조물에 적용하고 지중구조물 하중저감기법인 ETI의 지오폼을 해석변수로 경감효과 및 최적 지오폼을 제안하고자 한다. 해석연구에 고려된 지오폼은 EPS 12, EPS 15, EPS 19이다. 해석 결과로부터 지진하중시 최대 50%까지 지중하중이 경감되었으며, 수평처짐은 26%, 수직처짐은 8%이 경감되었다. 본 해석연구를 토대로 ETI 공법을 적용한 지중구조물이 정적 및 지진하중 하에서도 하중의 영향을 경감시키는 것을 확인할 수 있었다.

Most of aged water supply pipes have been replaced by the open cut method. However, this method has some limitations because water pipes, in many cases, are buried together with other underground facilities or are buried in the middle of high-traffic roads or in narrow alleyways where boring machines cannot be used. This research developed a pipe bursting device for small diameter pipes that enables pipe replacement without excavating the ground, by the busting of existing buried pipes followed by the traction and insertion of new pipes. As a results of examining the field applicability of the developed device, PE pipes and PVC pipes required the tractive force of 413.65～665.69 kgf and 457.43～791.35 kgf respectively, plus an additional 30 % tractive force per elbow. The proper number of bursting head was demonstrated that the connection of more than 2 heads could secure a stable bending radius of 15D. The developed device can be improved through field experiments involving various pipe types and pipe diameters, as well as presence/absence of elbow, so as to be utilized regardless of diverse variables according to the conditions of the soils surrounding existing pipes.

PURPOSES: Until now, the maintenance of road pavement has mostly involved passive maintenance methods with full maintenance only performed at the end of road life. Recently, there has been growing interest in solving the problem of reflection cracks that occur at joints during application of the overlay method of old concrete pavement. This study was aimed at solving the problem of reflective cracks around expansion joints and at evaluating the durability performance of pavement with interlayer reinforced-composites waterproofing system for concrete overlay. METHODS: This study was conducted to investigate the effect of an interlayer on prevention of reflection cracks and to improve the tensile, compressive, shear, and vertical stresses due to plastic deformation and vehicle cyclic loading. An integrated overlaying layer (5cm or 8cm) was used to evaluate the applicability according to objective indicators. RESULTS and CONCLUSIONS : It was confirmed that cracks did not occur in the section of the line overlaid by the interlayer and that the reflection cracks generated by the action of the lower layer sufficiently absorbed the horizontal movement of the asphalt 5cm pavement overlay. It also suppressed, or at least delayed, the progress of the vertical cracks. The interlayer reinforced composite membrane waterproofing method used in the packing layer, showed through repeated fatigue test results that the accumulated fatigue crack resistance was greater than 120,000 times.