In this study, according to the staking method of the fire hose in the indoor hydrant system, the number of kinks when the fire hose is deployed was measured and analyzed to examine how the staking method of the fire hose affects the kink when the hose is deployed. The fire hose staking method was classified into three types: donut-type, accordion-type, and hose hanger-type, and the walking speed and number of kinks were measured by repeating the experiment 5 times for male and female students. The results of the study are as follows. (1) Among the three types of fire hose staking methods, the donut-type staking method had an average of 92 times for male students and 86 times for female students on average. (2) The accordion-type and hose hanger-type staking methods showed similar results with an average of one or two kinks for both male and female students. (3) Regardless of the staking method, it was found that in general, male students with high walking speed had more kinking than female students with slow walking speed.

In this study, the purpose of this study was to examine the effect of twisting in the preparation of waterproofing in the process of unfolded donut-type staking method fire hoses in indoor hydrant system. The central pull-out method caused more twisting than the rolling method, and there was no significant difference in the number of twists according to the pull-out method in the case of male and female students. It was found that the time it took to untwist and prepare waterproofing was much shorter for male students. The angle valve and hose are connected, and the time to untwist and prepare for waterproofing after withdrawing the fire hose with the hose and nozzle connected was shorter than the unconnected state. In the rolling method, when a hose connected with two 15 m fire hoses was used and the angle valve-hose was connected, but the hose-nozzle was not connected, the least kinking occurred. The time to untwist and prepare for waterproofing was also the shortest. As a result, in the withdrawal method of the donut-type loaded fire hose in the indoor hydrant system, it is a rolling method rather than a central withdrawal method. With the angle valve and hose connected, unfold the fire hose with the hose and nozzle connected, if a large number of people unwind the twisted hose, the time to prepare for waterproofing can be shortened.

This study experimentally and analytically examines the seismic vulnerability of steel rack storage frames subjected to Korea earthquakes (2016 Gyeongju earthquake and 2017 Pohang earthquake). To achieve this aim, this study selects a three-story, one-bay steel rack frame with a typical configuration of rack frame in Korea. Firstly, the local behavior for frame components is examined by performing monotonic and/or cyclic load tests and the global response and dynamic characteristics of the subject rack frame are investigated by conducting a shaking table test. The analytical model of the rack frame is then created based on the experimental results and is used to perform nonlinear time history analyses with recorded Korea earthquakes. The seismic demand of the rack frame is considerably affected by the spectral acceleration response, instead of peak ground accelerations (peak floor accelerations). Moreover, the collapse fragility curve of the rack frame is developed using incremental dynamic analyses for the Gyeongju and Pohang earthquakes. Fragility results indicate that the ground motion characteristics of these earthquakes do not significantly affect the frame vulnerability at the collapse state.

본 논문은 적재설비의 바닥 구속조건에 따른 안전성을 평가하고자 한다. 평가를 위해서 국내에서 일반적으로 사용하고 있는 파렛트랙을 대상구조물로 선정하여 진동대 실험을 진행하였다. 진동대 실험을 위한 적재설비의 바닥 구속조건을 총 4가 지(1 bolt, 2 bolts, 4 bolts, Fixed)로 구분하여 진행하였다. 실험은 인공지진파를 증가시켜가며 진행하였고, 각 층별에서의 변위응답과 영구변형을 비교하였다. 이에 따른 실험 결과, 지진 강도에 따라 기둥 바닥의 구속조건을 달리 적용하는 것이 필요하다.

This paper intends to analyze the behavior characteristics of steel storage racks according to the constraints conditions by external loads such as seismic loads. In order to achieve these goals, the steel storage racks generally used in Korea were selected as target structures and shaking table tests were conducted. In order to confirm the behavior according to the constraints conditions, the foundation of the steel storage racks was constructed with three conditions (1 bolt, 4 bolts, fixed) and the experiment was carried out. As a result of the analysis of the data obtained through the experiment, it was confirmed that additional damper installation is needed rather than changing the condition of the bottom plate in order to secure the safety of the steel storage racks.

In this paper, a hydraulic damper was developed to protect the storage racks from earthquakes and the seismic performance of the storage racks was improved by applying the developed damper. In order to achieve these goals, the control capacity for the safety of the storage racks was determined, and a hydraulic damper satisfying the control capacity was designed and manufactured. In addition, the location of the hydraulic damper was determined through simulation. Finally, the shaking table test was carried out. As a result, the seismic performance improvement of the storage racks using the hydraulic damper was confirmed.