• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.6
• /
• pp.440-447
• /
• 2020

Masonry structures are used as bearing walls in small buildings, but they are generally considered non-bearing walls. They are used as partition walls that divide the interior spaces of the frame structures of buildings. In addition, wetting techniques that use mortar as an adhesive between blocks or bricks in construction are vulnerable to climatic conditions, especially cracks in mortar, which can cause conduction collapse of the walls in seismic loading. The purpose of this research was to propose a dry concrete block construction method that complements the weak axial shear stiffness and improves the weakness of the wet construction method as well as to investigate its structural behavior. In this study, the material properties of concrete blocks were examined, and the seismic performance of the proposed dry assembly structure was verified by structural behavior tests on horizontal cyclic loads. First, in these study results, concrete blocks can be applied to the dry block construction method instead of wet construction methods because they secure more than C-type blocks in KS regulations. Second, the structural performance of the wall against a horizontal cyclic load indicates that the resisting force of the assembly block wall is increased by increasing the horizontal length of the wall, forming several diagonal cracks. Finally, the proposed dry block wall structure requires a seismic performance assessment considering that the ratio of the shape of the wall by height and length is considered a major influence variable on the structural behavior under a horizontal load.

• Journal of the Korean Geotechnical Society
• /
• v.17 no.3
• /
• pp.83-94
• /
• 2001

본 연구에서는 상.하단으로 구분된 2개의 동일한 보강토옹벽에 대해서 상호 이격거리에 따른 수치해석을 수행하여 전면벽체의 수평변위, 전면벽체 배면의 수평토압, 보강토체 배면의 수평토압 그리고 보강재의 최대인장력 분포 및 크기변화 양상 등 다단식 보강토옹벽의 거동을 살펴보았다. 또한, 하단 옹벽에 증가되는 응력을 산정하고자 중첩의 원리를 적용한 2:1 응력분포법을 제시하였다. 수치해석 결과 이격거리가 증가함에 따라 상단옹벽이 하단옹벽에 미치는 영향이 감소하였으며 하단 옹벽 높이의 두배 이상 이격시, 상호 거동은 독립옹벽으로 거동하였다. 하단 옹벽내 응력 산정방법에 있어서 NCMA의 방법이 가장 보수적인 결과를 보였으며 본 연구에서 제시한 2:1 응력분포법중 주동파괴면을 고려하지 않은 방법이 수치해석 결과와 가장 유사하게 나타났다.

• Tunnel and Underground Space
• /
• v.17 no.5
• /
• pp.350-359
• /
• 2007

Most large cut slopes of open pit mines, roadways, and railways are steeply inclined and composed with rocks that do not contain soils. However, these rock slopes suffer both weathering and fragmentation. In the case of steep slopes, falling rock and collapse of a slope may often occur due to surface erosion. Cast-in place concrete and rubble work are the most widely used earth structure-based pressure supports that act as restraints against the collapse of the rock slope. In order to overcome the shortcomings of conventional retaining walls, a segmental grid retaining wall is being used with connects precasted segments to construct the wall. In this study, laboratory model test was conducted to estimate deformation behavior of segmental grid retaining wall with configuration of rear strecher, height and inclination of the wall. In order to examine the behavior characteristics of a segmental grid retaining wall, this research analyzes the aspects of spacial displacement through relative displacement according to change in the inclination of the wall. Also, the walls behavior according to the formation and status of the rear stretcher which serves the role of transferring the load from the header and the stretcher which make up the wall, the displacement of backfill materials in the wall, and the location of the maximum load were surveyed and the characteristics of displacement in the segmental grid retaining wall were observed. The test results of the segmental grid retaining wall showed that there was a sudden increase in failure load according to the decrease in the wall's height and the size of the in was greatly decreased. Furthermore, it revealed that with identical inclination and height, the structure of the rear stitcher did not greatly affect the starting point or size of maximum horizontal displacement, but rather had a stronger effect on the inclination of the wall.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.26 no.3
• /
• pp.103-110
• /
• 2022

The purpose of this study is to experimentally evaluate the stiffness and strength reduction according to the reinforcing bar details of the vertically divided reinforced concrete shear walls. To confirm the effect of reducing strength and stiffness according to vertical division, four real-scale specimens were fabricated and repeated lateral loading tests were performed. As a result of the experiment, it was confirmed that the strength and stiffness were decreased according to the vertical division. In particular, as the stiffness reduction rate is greater than the strength reduction rate, it is expected that safety against extreme strength can be secured when the load is redistributed according to vertical division. As a result of checking the crack pattern, a diagonal crack occurred in the wall subjected to compression control among the divided walls. It was confirmed that two neutral axes occurred after division, and the reversed strain distribution appeared in the upper part, showing the double curvature pattern. In future studies, it is necessary to evaluate the stiffness reduction rate considering the effective height of the wall, to evaluate additional variables such as wall aspect ratio, and to conduct analytical studies on various walls using finite element analysis.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.3
• /
• pp.609-623
• /
• 2018

If the ground is excavated in a depth which is deeper than the adjacent existing tunnel, the behavior of the braced wall is known to be greatly affected by the presence of the tunnel. By the way it is expected to be also affected by the structure on the ground surface, There are not many examples of studies which are conducted on this subject. As a result, largel scale model tests and analysis were conducted, to measure the behavior of the tunnel under the building whose location on the ground surface was varied during the adjacent ground excavation. For this purpose, the location of a building load was varied in 0 m, 1D, 2D on ground surface. In this paper, the behaviors of braced wall and adjacent tunnel was studied. Model tests in 1 : 10 scale were performed in real construction sequences. The size of test pit was $2.0m(width){\times}6.0m(height){\times}4.0m(length)$ in dimension. As a result, it was found that the stability of the existing tunnel under the influence of the building load on the ground surface adjacent to the braced wall.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.5 no.1
• /
• pp.63-72
• /
• 2001

상부 벽체와 하부 골조로 구성되는 주상복합건물은 전이층에서 수직적인 강성과 강도의 불연속성을 갖는다. 이러한 복합구조는 전이층에서 춤이 큰 보에 의하여 하중이 전달되면 설계시 매우 중요하게 고려하여야 하는 사항이다. 그러나 이에 대한 연구가 충분히 이루어져 있지 않으며 실제 전이보의 설계시 춤을 매우 크게 하여 요구되는 강도보다 큰 안전율이 고려되고 있다. 본 연구에서는 전이층의 단순화모델을 이용하여 보의 높이 및 지지면의 길이에 따른 아치거동의 변화를 조사하였다. 유한요소법을 이용하여 구조물을 분석하고 두 변수를 포함하는 헌치부재를 이용하여 그 효과를 기존 시스템과 비교하였다. 중요 변수와 헌치의 기울기는 1:1의 비율에서 사장 효율이 좋은 것으로 나타났으며, 이러한 결과를 전이보를 대신하여 사용한 결과 중력방향의 상부 아치거동에 대하여 효과적으로 작용하는 것으로 나타났다. 또한 응력 집중부위에서의 응력 감소와 깊이 전이보의 높이감소에 효과적으로 작용하는 것으로 나타났다.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.12 no.2
• /
• pp.59-66
• /
• 2008

In the construction site, to improve the man-dependent form work, non-stripping form has been studied but the developed non-stripping form was hard to applied with respect to the cost, form size and performance. This study is for evaluating the adaptability of the developed non-stripping form named as high performance permanent form (HPPF). To do this, the analytical approach and parametric study were performed based on the research for fundamental material characteristic of the HPPF. The target concrete structure is a wall structure because of its effectiveness of HPPF. To evaluate the structural efficiency of the HPPF applied wall structure, FEM analysis was performed to decide the maximum placing height at one time then it was applied to design the wall structure. In the result of the analysis, the HPPF applied wall structure showed the lots of advantages that it can reduce the cost resulted from reducing concrete and steel rebar even if it has same structural performance to the conventional concrete wall structure with same dimension. With this analysis result, it can be evaluated that the HPPF applied concrete structure can be a concrete structure with the long term durability in site.

• Journal of the Korean Geosynthetics Society
• /
• v.16 no.4
• /
• pp.119-127
• /
• 2017

This paper presents a study of reinforced earth model wall reinforced by geosynthetics subjected to vertical surcharge. 7 types of reinforced earth model wall were constructed in the model box($100cm{\times}140cm{\times}100cm$) to assess the deformation and stress behavior of model walls according to different tensile strength and laying number of reinforcement and surcharge pressures. 3 types of geosynthetics that have different tensile strength were used as reinforcement. The test was carried out by changing the number of reinforcement to 5, 7, 9, and surcharge pressure to 50, 100, 150, 200, 250 kPa. The model test found that the maximum lateral displacements occurred at the 0.7 H (H : Wall height) position from the bottom of the model wall and vertical stress was low in the smaller surcharge pressure and the larger tensile strength of reinforcement.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2014.11a
• /
• pp.184-185
• /
• 2014

The purpose of this study is to experimentally evaluate the variation characteristics of stiffness and impact resistance under the construction height of gypsum board wall at the actual construction site. The method suggested in previous study was applied on the test method of horizontal load resistance and impact resistance. As a result of horizontal load resistance test, when the wall height is 2,400 mm, the maximum displacement is 13.6 mm and residual deformation is 0.5 mm, and when the wall height is 3,000 mm, the maximum displacement is 31.3 mm and the residual displacement is 6.8 mm. As a result of impact resistance test, the residual deformation of each specimen at 20 cm of fall height were 1.02 mm and 0.08 mm, respectively, the residual deformation at 40 cm of fall height were 1.58 mm and 0.35 mm, respectively, and the residual deformation at 60 cm of fall height were 2.23 mm and 2.48 mm, respectively.

• The Journal of Engineering Geology
• /
• v.18 no.3
• /
• pp.277-285
• /
• 2008

For the soil nailing, recently, its application is expanded, but there is no officially approved method to design it yet. Furthermore, there are a great number of design valuables in soil nailing, it is also used without clear data under the situation that uncompleted detailed research on the sensibility between design variables. Especially, there has no deal with the installation angle of the nail - the major contents in this study. Therefore, this study based on the theoretical estimation analyzed safety rate about the angle of the nail, unit weight, adhesive force, internal friction angle and tensile farce worked on nail in the case of the rear of pond side is both horizontal and perpendicular. As a result, it could be verified that the safety rate increased on every cases in the situation of the nail installation angle was in upward direction than in downward direction.