Among the soft ground improvement methods, PBD is the most common construction method because it is cheap and construction is fast. However, if the ground is rigid, additional work is required. In this study, the structural safety, natural vibration, and safety angle of the steel vertical tower structure were evaluated in the development of the PBD composite perforator which can be combined with drilling work and PBD construction. Structural safety was assessed when the wind load of 20 m/s was simultaneously applied to the PBD construction load of 20 tons, the perforating operation of 25 tons, and the wind speed of 50 m/s was applied only to the wind load. The natural frequencies were evaluated up to the sixth mode, and the safety angle was evaluated for static and dynamic safety angles.

ABSTRACT
 1. 서 론
 2. 설계 및 해석 조건
  2.1 설계 조건
  2.2 풍하중 조건
  2.3 구조해석조건
  2.4 안전각 평가
 3. 구조 안전성 평가 결과
  3.1 PBD 작업하중에 의한 구조 안전성
  3.2 천공 작업하중에 의한 구조 안전성
  3.3 최대 풍속에 의한 구조 안전성
  3.4 고유진동 해석
  3.5 안전각 평가
 4. 결 론
 References

• 김민호(Smart Vehicle Dep’t of Sohae college) | Min-Ho Kim Corresponding Author