주택법에 근거하여 철근콘크리트 공동주택의 리모델링 시 최대 3개층의 수직증축 및 기존 세대수의 15%까지 증축이 가능하게 되 었다. 수직증축 리모델링 가능 여부는 안전진단 기준 및 매뉴얼을 바탕으로 기울기 및 침하, 내하력, 내구성 평가 부문에 대한 조사를 통하여 평가하고 판정하도록 되어 있다. 그러나 현행 증축형 리모델링 안전진단 기준 및 매뉴얼은 재건축 안전진단 기준과 비교하여 조사대상표본 수를 증대시키는 등 보수적인 것으로 평가되고 있으며, 특히 내구성 평가 부문에 검토 및 개선이 필요한 것으로 생각된다. 따라서 본 연구에서는 수도권 지역 공동주택의 증축형 리모델링 안전진단 조사 사례에 대한 내구성 조사 항목 중 콘크리트 탄산화를 대상으로 통계적인 수법에 의해 표본 수 합리화 방안을 제시하였다.

The 'Housing Act (‘14.04), which permits the remodeling of old apartment buildings, has been implemented. In particular, vertical remodeling is generally implemented by adding 2~3 floors above the top floor of existing apartments. Technically, it is necessary to reinforce the existing pile due to the increase of vertical, horizontal, seismic load, etc. However, the existing piles are loaded simultaneously and so each pile was constructed at limited base space for application of reinforcement method. The bearing capacity of existing piles decreases due to vertical expansion so the bearing capacity of the piles must be confirmed by the indirect method(laboratory test etc.) in the first safety diagnosis and by the direct method(field test etc.) in the second safety diagnosis.

The recent revision of Housing Act allow vertical extension up to maximum 3 stories and increase the ratio of floor area to site up to 15%. Currently, the feasibility of performing vertical extension is evaluated based on safety diagnosis provisions and manuals for vertical extension with preliminary investigations on slope, deflection, load-bearing capacity, and durability. However, a need for more reasonable evaluation methodology for the preliminary investigation is still required because the current procedures are borrowed from safety diagnosis provisions and manuals for reconstruction without detailed examinations on evaluation criteria and sampling methods. Accordingly, this study is intended to suggest a method to obtain feasible sampling numbers for durability assessment by analyzing field data on concrete carbonation, chloride content, and steel corrosion. The results of this study are expected to be beneficial for establishing more reasonable field sampling number, and in turn, more reliable durability assessment protocol for vertical extension.

In this paper, we determine the number of reinforced pile foundations required for vertical extension remodeling through analysis of construction steps on all combinations of load including the seismic load and vertical load.

In this paper, construction staged-analysis is introduced to understand how the additional loads transfer to existing and added piles. Added piles are not able to take on the existing load due to mechanical problem.