패널식 옹벽의 대절토부 보강에 따른 지반의 거동특성 분석

Abstract

Analysis of the behavior characteristics of the ground according to the reinforcement of large cuttings of panel retaining walls Park, Jun O Advisor : Prof. Kim, Daehyeon, Ph. D. Department of Civil Engineering Graduate School of Industrial Technology and Entrepreneurship, Chosun University In performing large land construction, it is very important to secure stability during the construction of the retaining wall. Currently, various technologies and new technologies for securing the stability of wall, but there are different design limitations on the field index, but there are different designation of the field indicators. As a result, economic and human damage is continuously occurring at the construction site. A total of five stages of retaining wall construction are scheduled for the study site in this study, but cracks in the upper part of the retaining wall, subsidence of the front surface of the retaining wall, and outflow of rainwater were confirmed at the time of completion of the second stage of construction. This does not clearly reflect the construction of the sub-ground of the current research site, so it was intended to identify problems with facilities in the relevant research area through a review of existing stability reviews and to propose solutions such as suggesting reinforcement methods for stable and economic maintenance. As a result of the analysis, it was confirmed that the safety factor during dry season, rainy season, and earthquake exceeded the standard safety factor in all sections 1 to 4 of the cutting parts before construction. This can be determined that the method applied in this study is appropriate based on the physical properties of the ground and the current stratum distribution status derived from the ground survey. After the completion of the first and second stages of the retaining wall construction, problems with cracks and subsidence in the upper part of the retaining wall and excellent outflow of the front of the retaining wall were discovered, and the results of the existing stability review were done. It was confirmed that it was a problem caused by groundwater leakage because there was no clear review of the colluvial soil in the existing design stage, and a stability analysis of the slope was conducted by placing a groundwater level line at the top of the retaining wall to conservatively reflect the groundwater level conditions. As a result of the analysis, it was confirmed that the safety factor during the rainy season was 1.31, exceeding the standard safety factor of 1.3, but it was confirmed that the safety factor during the earthquake was 1.12, which did not satisfy the standard safety factor of 1.3. The colluvial soil layer is highly water-permeable and easily collapses when it comes into contact with water, so it is easy to penetrate by rainfall and easily loses the shear strength of the soil, so a method that can reinforce the foundation of the colluvial soil and reduce the initial groundwater level is needed. Accordingly, it is deemed urgent to secure safety rates by excluding groundwater by applying micro-pile using grouting to the existing 1st and 2nd stage retaining walls, and installing horizontal drainage holes for the 3rd, 4th, and 5th stage retaining walls scheduled to be constructed.