• Steel and Composite Structures
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• 제27권5호
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• pp.623-632
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• 2018

Performance-Based Plastic Design (PBPD) method has been recently developed to evaluate the behavior of structures in different performance levels. The PBPD method utilizes a base shear force and a lateral load pattern that are estimated based on energy and yielding mechanism concepts. Using of current lateral force pattern results in weak structural members in upper stories of a structure so that the values of the story drift in these stories are larger than the target drift, particularly in high-rise buildings. Therefore, such distribution requires modifications to overcome this drawback. This paper proposes a modified lateral load pattern for steel Eccentrically Braced Frames (EBFs) based on parametric study. In order to achieve the modified load pattern, a group of 26 EBFs has been analyzed under a set of 20 earthquake ground motions. Additionally, results of nonlinear dynamic analyses of EBFs have been post-processed by nonlinear regression analysis in order to derive the new load pattern. To prove the efficiency of present study, three EBFs as examples were designed by modified pattern and current PBPD distribution. Inelastic dynamic analyses results showed that the story drifts using modified lateral load pattern were well within the target values in comparison with current pattern in PBPD, particularly where the effect of the height is significant. The modified load pattern reduces the possibility of underdesigning in upper levels and overdesigning in lower levels of the frames.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.241-246
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• 2007

The capacity of a lateral load resistance of a joint with Jangbu-connection of Dori-directional frame in traditional wood structure system was studied, through experiments of 1/2 scaled and T-shaped 7 subassemblies of joint of Dori-directional frame for Deawoongjeon of Bongjungsa. From the experiment, it was shown that the capacity of a lateral load resistance was influenced by the vertical load confining joint and not influenced by the number of Chok and the depth of Changbang, And lateral load resistance mechanism is developed by the restraint between the vertical load and the contacting edge of column; if structure is pushed to the left, the top-right end of Pyeongju contacts with Changbang and left Changbang loses the contacts with Pyeongju and therefore only right Changbang can resist to lateral load.

• Steel and Composite Structures
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• 제1권2호
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• pp.201-212
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• 2001

In order to investigate the effect of the loading rate on the mechanical behavior of SRC shearwalls, we conducted the lateral loading tests on the 1/3 scale model shearwalls whose edge columns were reinforced by H-shaped steel. The specimens were subjected to the reversed cyclic lateral load under a variable axial load. The two types of loading rate, 0.01 cm/sec for the static loading and 1 cm/sec for the dynamic loading were adopted. The failure mode in all specimens was the sliding shear of the in-filled wall panel. The edge columns did not fail in shear. The initial lateral stiffness and lateral load carrying capacity of the shearwalls subjected to the dynamic loading were about 10% larger than those subjected to the static loading. The effects of the arrangement of the H-shaped steel on the lateral load carrying capacity and the lateral load-displacement hysteresis response were not significant.

• Steel and Composite Structures
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• 제15권6호
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• pp.705-724
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• 2013

The behaviour of steel column at elevated temperature is significantly different than that at ambient temperature due to its changes in the mechanical properties with temperature. Reported literature suggests that steel column may become vulnerable when exposed to fire condition, since its strength and capacity decrease rapidly with temperature. The present study aims at investigating the lateral load resistance of non-insulated steel columns under fire exposure through finite element analysis. The studied parameters include moment-rotation behaviour, lateral load-deflection behaviour, stiffness and ductility of columns at different axial load levels. It was observed that when the temperature of the column was increased, there was a significant reduction in the lateral load and moment capacity of the non-insulated steel columns. Moreover, it was noted that the stiffness and ductility of steel columns decreased sharply with the increase in temperature, especially for temperatures above $400^{\circ}C$. In addition, the lateral load capacity and the moment capacity of columns were plotted against fire exposure time, which revealed that in fire conditions, the non-insulated steel columns experience substantial reduction in lateral load resistance within 15 minutes of fire exposure.

• 한국지반공학회논문집
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• 제32권4호
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• pp.41-49
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• 2016

해상구조물을 지지하는 말뚝기초는 바람, 조류, 파랑 등의 영향으로 횡방향 반복하중을 지배적으로 받는다. 본 연구에서는 횡방향 반복하중이 말뚝의 횡방향 극한지지력에 미치는 영향을 평가하기 위하여, 서로 다른 세 가지 상대밀도(40%, 70%, 90%)로 조성된 모래지반에서 모형말뚝시험을 수행하였다. 상대밀도 40%로 조성 된 모래지반에서는 횡방향 반복재하 시 말뚝 주변 지반이 조밀해짐에 따라 횡방향 극한지지력이 증가하였다. 반면, 상대밀도 70%와 90%로 조성 된 모래지반에서는 횡방향 반복재하 시 말뚝 주변 지반의 교란효과로 인하여 횡방향 극한지지력이 감소하였다. 이러한 횡방향 극한지지력의 증가 및 감소효과는 횡방향 반복하중의 크기가 커질수록 더욱 명확하게 나타났으며, 모래지반의 포화 여부에는 큰 영향을 받지 않았다. 모형시험 결과를 활용하여 모래지반의 상대밀도, 횡방향 반복하중의 크기에 따른 말뚝의 횡방향 극한지지력 산정 식을 제안하였고, 이를 횡방향 반복하중을 지배적으로 받는 말뚝의 설계 시 활용 가능하도록 하였다.

• 한국지반신소재학회논문집
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• 제16권4호
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• pp.43-55
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• 2017

본 연구에서는 교통시설 하부구조인 옹벽(중력식 옹벽)에 가해지는 수평토압의 크기에 교통하중이 미치는 영향을 파악하였다. 교통시설 하부구조인 옹벽에서 상부 교통하중이 옹벽 안전성에 미치는 영향에 관한 연구가 부족한 실정이다. 교통하중으로 인해 옹벽에 유발되는 수평토압은 도로의 차선 수, 차량 하중의 크기 및 옹벽으로부터 떨어진 거리 등의 영향을 받을 것이다. 따라서 이들 변수를 대상으로 수치해석한 결과, 차량하중 이격거리가 옹벽 높이보다 클 경우 수평토압의 변화는 미미하였다. 따라서 상부에 교통하중을 받는 도로옹벽 설계 시 옹벽내측으로부터 교통하중까지의 이격거리가 옹벽의 높이 내의 교통하중만을 고려하는 것이 실용적이고 합리적이다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.913-922
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• 2009

Fourteen model pile load tests using a calibration chamber and instrumented model pile were preformed to investigate the variation of the behaviors of driven piles in sands with soil and lateral cyclic loading conditions. Results of the model tests showed that the first loading cycle generated more than 70% of the pile head rotation developed for 50 lateral loading cycles. Lateral cyclic loading also made an increase of the ultimate lateral load capacity of piles for $K_0$=0.4 and an decrease for $K_0$ higher than 0.4. Higher portion of the increase or decrease in the ultimate lateral load capacity by lateral cyclic loading was generated for the first loading cycle due to densification of loosening of the soil around the pile by lateral cyclic loading. It was also observed that a two-way cyclic loading caused higher ultimate lateral load capacity of driven piles than a one-way cyclic loading. When the pile was in the ultimate state, the maximum bending moment developed in the pile increased with increasing $K_0$ value of soil and was insensitive to the magnitude and number of lateral cyclic loading.

• 한국산학기술학회논문지
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• 제16권5호
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• pp.3548-3556
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• 2015

해상풍력기초를 설계함에 있어 사용하중에 대해 극한적인 조건뿐만 아니라 지속적인 동적하중에 대해 기초의 거동을 정확하게 파악하여 안정적이고 경제적인 기초를 개발할 필요성이 있다. 이를 위하여 강관말뚝을 일정비율로 축소시켜 모형말뚝을 제작하고, 모형토조에 모래층을 500mm의 높이로 포설한 후 모형말뚝을 모델링하여 정적 및 반복 수평재하실험을 실시하였다. 그 결과, 정적수평재하시 모형말뚝의 길이/직경(L/D)이 클수록 하중에 따른 변위는 증가하는 반면, 반복수평재하시 하중재하 횟수가 증가할수록 반복수평하중 1회당 발생하는 말뚝의 수평변위는 감소하였고 지반이 조밀할수록 반복수평하중에 의한 말뚝의 극한수평지지력의 증가율이 작아지는 것으로 나타났다. 또한 휨모멘트의 분포형상은 지반의 상대밀도에 상관없이 유사한 형태를 보였으며, 최대휨모멘트는 지표면으로부터 170mm지점에서 발생하는 것으로 나타났다. 그리고 지반의 상대밀도가 증가할수록 정적수평재하와 반복수평재하 조건에서 발생하는 최대휨모멘트는 증가했다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1703-1712
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• 2010

The safety of tilting train running on curved track is, in general, evaluated with a derailment coefficient calculated by the ratio of wheel load and lateral force, Particularly on curve, the wheel load and lateral force on rail may cause trackbed to be deformed, depending on their intensity, and moreover, often result in critical accident such as derailment. This study hence was intended to identify the cause of wheel load and lateral force so as to suggest the allowable wheel load reduction rate, lateral force limit and derailment coefficient, thereby quantitatively evaluating the operational safety of tilting train. This study therefore was aimed to analyze the wheel load and lateral force occurred during tilting train's operation on circular curve in such a way of comparing with traditional trains, by axle and speed, in a bid to eventually evaluate the operational safety of tilting train.

• 산업기술연구
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• 제25권A호
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• pp.15-22
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• 2005

In order to evaluate seismic performance of multi-degree-of-freedom bridge structure, moderate lateral load distribution methods using the pushover analysis were developed by many researchers. One of important variables to improve an accuracy of pushover analysis is lateral load distribution. In this study, pushover analyses were performed using the five types of lateral load distribution and seismic performances were evaluated by capacity spectrum method (CSM). To verify an accuracy of suggested lateral load distribution, the maximum displacement estimates by the CSM were compared to those by inelastic time history analysis.