본 연구에서는 보강토 옹벽 점검 자료를 바탕으로 보강토 옹벽의 상태평가항목의 가중치를 새롭게 제안하고 결함점수 및 결함지수 를 제안하였다. 161개소의 보강토 옹벽의 점검결과를 근거로 다중회귀분석과 엔트로피 기법을 이용하여 상태평가항목별 가중치를 산정하였 으며, 또한 전문가를 대상으로 AHP 기법을 활용하여 평가항목별 가중치를 산정하였다. 각 기법에서 도출된 가중치를 활용하여 혼한 가중치를 제안하였으며, 제안 가중치를 토대로 결함점수 및 결함지수를 제안하여 기존 161개소 현장에 적용하여 현재의 가중치와 제안 가중치에 의한 현장별 위험도 순위를 비교 분석하였다. 다중회귀분석, AHP 기법, 엔트로피 기법을 활용하여 분석한 결과 상태평가항목의 가중치 순위가 변동 이 컸으며, 현재 상태평가항목의 가중치와 달리 가중치 순위의 중복은 발생하지 않았다. 특히, 다중회귀분석 결과에서는 특정 상태평가항목이 전체 가중치의 70% 이상을 차지하는 결과가 도출되었다. 제안한 혼합 가중치를 기존 보강토 옹벽 데이터에 적용한 결과, 상태평가항목의 가중 치 중복은 발생하지 않았으며, 대상 보강토 옹벽 161 개소 중 16 개소의 위험도 순위 상승과 31 개소의 위험도 하락이 발생하였다.

Collapse of reinforced earth retaining wall due to improper design and construction is still occurring during construction and operation. While most studies of reinforced retaining walls are focused on the mechanistic behavior, there is little study on the improvement of assessment item, which is used to examine the safety of retaining wall, based on the existed inspection data. This study proposed new weighting factor of assessment item by utilizing multiple regression analysis technique, AHP method, and entropy method for the existed inspection data of reinforced earth retaining wall. Compared to the existed weighting factor, the value and the rank of proposed weighting factors are changed. By applying the proposed weighting factors to the existing retaining walls of 161 sites, fragility region of 47 sites is changed.

Collapse of reinforced earth retaining wall due to improper design and construction is still occurring during construction and operation. While most studies of reinforced retaining walls are focused on the mechanistic behavior, there is little study on the improvement of assessment item, which is used to examine the safety of retaining wall, based on the existed inspection data. This study proposed new weighting factor of assessment item by utilizing multiple regression analysis technique, AHP method, and entropy method for the existed inspection data of reinforced earth retaining wall. Compared to the existed weighting factor, the value and the rank of proposed weighting factors are changed. By applying the proposed weighting factors to the existing retaining walls of 161 sites, fragility region of 47 sites is changed.

Steel net gabion is eco-friendly retaining wall structure showing favorable ability to overcome construction and environmental restriction and also to resist corrosion, chemical attack and degradation. This paper is dealt with the applicability of gabion metal net as a substitution of existing strengthening material. Pull out test was carried out to verify the applicability of gabion metal net. According to results, the increase of surcharge loading and horizontal load resulted in a yield of metal net. The stress at the time of yield was in the range of elasticity. Accordingly, gabion metal net can be substituted for existing geogrid and there is a need for experiment and analysis of arrangement direction and durability of gabion steel net.

This paper presents eco-friendly planting method to overcome the problems of existing concrete retaining wall and gabion retaining wall, respectively, based on the examination on existing concrete and gabion retaining wall. Prior to doing this, proper design method was provided through pull out test. Planting method using gabion metal net and L shape green net retaining wall were compared and analyzed. According to this study, it is confirmed that reduction of construction period and economical profit in construction can be achieved by both manufacturing at the factory and self procurement at the job site as well as the use of metal net, which is applied as a substitution of existing strengthening material. For the effect of planting method, the use of L shape green net retaining wall shows superiority to environment-friendly gabion retaining wall in its ability to rootage and germination of the grass. The L shape green net retaining wall had excellent performance in helping rootage of grass and prevention of soil leakage, and even if raining period, remarkable damage of planting mat does not occur when planting mat is applied.

본 연구에서는 블록형 보강토 옹벽에 경사계, 침하계, 토압계, 수직 및 수형 변위계, 스트레인게이지 등의 각종 계측기를 매설하여 시공 중 및 시공 후의 보강토 옹벽의거동과 전면벽체에 작용하는 수평토압의 크기 및 분포형태. 그리드에 발현되는 변형 형태 및 인장력의 크기와 침하특성 등을 옹벽의 직선부와 곡선부로 구분하여 분석하였다.