• Journal of the Korean Society of Hazard Mitigation
• /
• v.8 no.3
• /
• pp.77-86
• /
• 2008

A database program is constructed by collecting all information related to shallow foundations such as measured load-settlement data, foundation shapes and sizes, properties of soils under the foundation and various measured data obtained from field investigation methods including CPT, PMT and SPT etc.. Based on the database program, a special program module is developed for performing statistical analyses of reliability and accuracy of predicting equations used for calculation of settlement of the shallow foundations. Special interests are focused not only on the settlement, but also on the settlement to width ratio (s/B). Results of the reliability and accuracy analyses on five available settlement equations are provided. Conclusions based on the provided results can be confirmed by extending number of related reliable data about the shallow foundations and can be adapted as guidelines for design of the shallow foundations.

• Journal of the Korean GEO-environmental Society
• /
• v.22 no.10
• /
• pp.31-36
• /
• 2021

Estimation of accumulated rotational angles and settlements are critical in design of wind turbine foundation. However, there have been few exploring the response of bucket foundation to long-term cyclic loading. We performed a series of three-dimensional finite element analyses of bucket foundations installed in sands. An empirical formulation which captures the stiffness degradation observed in cyclic triaxial tests implemented into the finite element analysis in the form of a user subroutine. Using the stiffness degradation model the accumulated rotation and displacement of bucket foundation were calculated. Additionally, important factors affecting the response under cyclic loading were assessed.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.6
• /
• pp.5-18
• /
• 2009

In construction of buildings in Korea, the buildings are frequently founded on the weathered ground (weathered soil/rock, fractured rock). In this case, to make a full use of a bearing capacity of a weathered ground for economic design, the shallow mat foundation system could be used. In this study, we have researched three cases of mat foundations on the weathered ground in Korea, and analyzed and considered the design procedures and the reinforcing methods. That is, we have considered the detail design, analysis proceedings, the ground settlement evaluation proceedings, the rock face mapping evaluations after excavation and reinforcing methods of the mat foundation on the weathered ground. And large scale plate load tests on the weathered ground supporting the mat foundation were performed and also load bearing capacity and settlement of actual mat foundation, considering the scale effect, were evaluated.

• Journal of Korea Technology Innovation Society
• /
• v.14 no.2
• /
• pp.177-204
• /
• 2011

Recently the government expands its investment in basic research to overcome the limit of technology catch-up strategy. At this point, Korea's R&D supporting system needs to be evaluated whether it is appropriate to support creative basic research. Therefore, this study approaches to analyze the cases of basic research supporting system about the characteristics of basic research and necessary systematic requirements. This research discussed the necessity for introducing the paradigm of policy management system of basic research. Also it found that the performance of basic research is very important element for the effectiveness of research itself as well as continuous appropriacy of the system.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.14 no.3
• /
• pp.178-185
• /
• 2010

This paper presents the evaluation of foundation stability according to decrease of the foundation contact area on the ground. In order to carry out this research, the experimental and numerical studies are performed. In the experimental study, the carefully controled laboratory model tests are carried out with different foundation size and types. The model test results are analyzed and interpreted by analytical and numerical calculation in order to verify both results obtained from experimental and numerical studies. It is clearly found from the results that the foundation stability is considerably reduced when the foundation contact area ratio is less than 75%. This research may be very useful to develop the economical foundation type.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.12
• /
• pp.19-25
• /
• 2010

Inventory survey is process collecting data about cut slope. It's different from inspection. Collected data are being used get at status about cut slope along national roads. And we analyse between current situation and data about collapse slope. It helps finding better method about maintenance of cut slope. We found changes in the situation between data at present and data at 10 years ago. We will research collapse and counterplan by cause.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2017.11a
• /
• pp.374-375
• /
• 2017

본 논문에서는 국내외 붕괴사례 DB를 조사하여 붕괴사고 유형, 대상, 발생 시기, 발생 국가, 사망자수, 발생공정, 사고발생 원인 등에 대하여 통계적인 분석을 실시하였다. 조사자료는 시설안전공단, 안전보건공단, 각종 기관 보고서, 통계자료, 기타 뉴스 자료 등이며 원자료 형태의 특성대로 코딩하여 분석하였다. 전반적인 경향을 보기 위한 것으로 기초분석을 중심으로 하였으며 시간적 공간적 범위의 제한을 두지 않았다. 해외 선진국에서는 일부 재난원인을 밝히는데 과학적인 방법의 하나로 포렌식기법을 적용하여 분석하기도 하나 실제적으로 붕괴 분야에서 적용된 사례는 많지 않다. 본 연구에서는 붕괴 분야에 포렌식 기법을 적용하기 위한 전 단계로 붕괴사례에 대한 전반적인 분석이 이루어진 기초연구이다.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.25 no.3
• /
• pp.68-76
• /
• 2021

Storage racks have suffered huge losses due to earthquakes, but related research and regulations are relatively insufficient non-structural elements compared to the structural elements. In this study, we tried to experimentally analyze the behavioral characteristics of storage racks due to external force according to the fixing conditions of the column-foundations connection of storage racks. In general, the column-foundations connection of storage racks is installed according to the user's convenience without installation standards and regulations. For this reason, this study conducted a behavior analysis test on four full-scale storage racks with the condition of column-foundations connection of four typical storage racks. The behavior characteristics analysis test was performed by two-direction of the shake table with El-Centro seismic wave. To confirm the behavior characteristics according to the magnitude of the seismic load, 50% ~ 150% of the seismic waves were increased by 50% for each test. In addition, a resonance search test was conducted to confirm the natural frequency of each storage racks foundations fixing condition. Among the data obtained through the test, the displacement of the top layer and the permanent displacement after the test were compared for each condition to analyze the behavior characteristics of the column-foundations fixed conditions of the storage racks. As a result, the change of natural frequency was small in storage racks due to the change of the conditions of the foundations, and the behavior characteristics were changed due to the difference of the restoring force due to the change of the storage racks foundations condition rather than the influence of the natural frequency of the input load.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.1
• /
• pp.219-227
• /
• 2013

This study analyzed the effect of performance connected-type foundations of behavior and the connected beams according to the characteristics into soft clay transmission tower foundation. For this purpose, the finite element analysis model was built and connected to the transmission tower foundation mat and the contact area of the connection beam by the percentage change in the behavior and resistance characteristics were analyzed and finite element verification of the validity of the analytical model was conducted using connected-type transmission tower results of the model experiments constructed, and effective connected-type transmission tower basis of the behavior of connected beams were selected by analyzing the effect due to the increase of the stiffness. In addition, weak analysis by connected beam self-bending moment distribution was conducted.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.4
• /
• pp.853-861
• /
• 2015

In this study, FDM modelling with axisymmetry condition and interface element was verified whether it is reasonable to estimate compositive behavior of a piled raft foundation. To this end, the modelling validity of piled raft foundations was estimated by comparing and analyzing numerical analysis results and laboratory model test results. Also, load bearing ratio of a raft is analyzed by performing sensitivity analysis of foundation parameters with the actual field conditions. As a result of this study, correlation between bearing capacity and vertical displacement of numerical results turned out to be similar with that of a laboratory model test. In addition, ultimate bearing capacity of piled rafts and load bearing ratio of the raft is calculated to be similar in both cases. The load bearing ratio of the raft was also estimated to be in the range of 33% to 52% from the sensitivity analysis. The results were confirmed to be similar to the previous studies. Therefore, it can be inferred that piled rafts can be effectively modelled applying axisymmetry condition and interface element.