보강형 Sheet pile공법의 적용성 및 암반층 근입 개선 효과에 관한 연구

Abstract

가물막이 공법 중 Sheet pile공법은 타 공법에 비해 시공성이 용이하고 경제적이며 장점이 많은 공법으로 일반적으로 많이 사용되고 있다. 하지만 이 공법은 암반지반에는 시공이 어려워 타입이 가능한 지반에 한해서만 적용이 가능하며 수심이 깊고 암반을 굴착해야 하는 현장의 경우 높은 공사비가 소요되는 중력식 가물막이를 적용하거나 암반 전체를 천공해서 Sheet pile을 근입하는 비효율적인 방법을 적용해야 한다. 본 연구에서는 이러한 Sheet pile의 암반시공 문제 해결을 위한 공법으로 보강형 Sheet pile공법을 연구대상으로 하여 공법의 특성 및 적용성에 관한 연구를 수행하였다. 이 공법은 현장에서 많은 시행착오를 통해 발전되어진 공법으로 이미 시공현장에 많이 적용되고 있으나 이론적인 검증이나 복합 벽체의 거동에 대한 이해가 부족한 상황이다. 그러므로 본 연구에서는 보강형 Sheet pile공법의 거동을 수치적으로 분석하였고 나아가 가물막이공사에 가장 많이 적용되고 있는 2열 가물막이형태의 동일한 조건에서 일반 Sheet pile공법과 보강형 Sheet pile공법의 수치해석을 수행하여 두 공법의 거동 특성 및 부재력 비교를 통해 강성 비교를 하였다. 또한 시공성 및 경제성에 대한 비교를 수행하여 보강형 Sheet pile공법의 적용성 및 효과에 관한 종합적인 검토를 수행하였다. 그 결과 동일한 조건에서 두 공법은 유사한 거동특성과 강성을 갖는 것으로 나타났으며 2열 보강형 Sheet pile공법이 2열 일반 Sheet pile공법에 비해 작은 차이지만 부재력이 더 작게 나타났고 시공성이나 경제성면에서도 더 우수한 것으로 나타났다.|Compared with other methods, Sheet pile method of cofferdam methods is in general use due to easy constructability, economic efficiency, and a number of advantages. However, this method is difficult to use for construction of rock fields and is applicable only to proper ground. In case of construction site with deep water and that needs rock excavation work, a gravity cofferdam demanding high cost of construction or an inefficient method to drill the entire rock and insert Sheet pile should be applied. This study examined the characteristics and applicability of Stiffened Sheet pile method as a solution to the problem of Sheet pile constructed above rock ground. This method has been developed through trials and errors in the field site and already been applied at construction sites, but there is a lack of understanding of theoretical investigation and behavior of composite wall. Therefore, this study analyzed the behavior of Stiffened Sheet pile numerically. Further, it conducted numerical analysis on general Sheet pile method and Stiffened Sheet pile method under the same conditions of a two-row cofferdam type which is most applied to cofferdam construction, and performed stiffness comparison by comparing behavior characteristics and member force of the two methods. Also, it overall examined applicability and effectiveness of Stiffened Sheet pile in comparison with constructability and economic efficiency. As a result, under the identical conditions, the two methods were confirmed to have similar behavior characteristics and stiffness, and a two-row Stiffened Sheet pile method has a little less member force and better constructability and economic efficiency than a two-row general Sheet pile method.; Compared with other methods, Sheet pile method of cofferdam methods is in general use due to easy constructability, economic efficiency, and a number of advantages. However, this method is difficult to use for construction of rock fields and is applicable only to proper ground. In case of construction site with deep water and that needs rock excavation work, a gravity cofferdam demanding high cost of construction or an inefficient method to drill the entire rock and insert Sheet pile should be applied. This study examined the characteristics and applicability of Stiffened Sheet pile method as a solution to the problem of Sheet pile constructed above rock ground. This method has been developed through trials and errors in the field site and already been applied at construction sites, but there is a lack of understanding of theoretical investigation and behavior of composite wall. Therefore, this study analyzed the behavior of Stiffened Sheet pile numerically. Further, it conducted numerical analysis on general Sheet pile method and Stiffened Sheet pile method under the same conditions of a two-row cofferdam type which is most applied to cofferdam construction, and performed stiffness comparison by comparing behavior characteristics and member force of the two methods. Also, it overall examined applicability and effectiveness of Stiffened Sheet pile in comparison with constructability and economic efficiency. As a result, under the identical conditions, the two methods were confirmed to have similar behavior characteristics and stiffness, and a two-row Stiffened Sheet pile method has a little less member force and better constructability and economic efficiency than a two-row general Sheet pile method.