• Title/Summary/Keyword: Historic behavior

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Assessment of non-prismatic beams having symmetrical parabolic haunches with constant haunch length ratio of 0.5

  • Yuksel, S. Bahadir
    • Structural Engineering and Mechanics
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    • v.42 no.6
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    • pp.849-866
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    • 2012
  • Single span historic bridges often contain non-prismatic members identified with a varying depth along their span lengths. Commonly, the symmetric parabolic height variations having the constant haunch length ratio of 0.5 have been selected to lower the stresses at the high bending moment points and to maintain the deflections within the acceptable limits. Due to their non-prismatic geometrical configuration, their assessment, particularly the computation of fixed-end horizontal forces (FEFs) and fixed-end moments (FEMs) becomes a complex problem. Therefore, this study aimed to investigate the behavior of non-prismatic beams with symmetrical parabolic haunches (NBSPH) having the constant haunch length ratio of 0.5 using finite element analyses (FEA). FEFs and FEMs due to vertical loadings as well as the stiffness coefficients and the carry-over factors were computed through a comprehensive parametric study using FEA. It was demonstrated that the conventional methods using frame elements can lead to significant errors, and the deviations can reach to unacceptable levels for these types of structures. Despite the robustness of FEA, the generation of FEFs and FEMs using the nodal outputs of the detailed finite element mesh still remains an intricate task. Therefore, this study advances to propose effective formulas and dimensionless estimation coefficients to predict the FEFs, FEMs, stiffness coefficients and carry-over factors with reasonable accuracy for the analysis and re-evaluation of the NBSPH. Using the proposed approach, the fixed-end reactions due to vertical loads, and also the stiffness coefficients and the carry-over factors of the NBSPH can be determined without necessitating the detailed FEA.

The Construction of Initial Analytical Models Structural Health Monitoring of a Masonry Structure

  • Kim, Seonwoong;Kim, Ji Young;Hwang, In Hwan
    • International Journal of High-Rise Buildings
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    • v.4 no.3
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    • pp.191-198
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    • 2015
  • It is important to accurately predict structural responses to external excitations such as typhoons and earthquakes when designing structures for serviceability. One of the key procedures to predict reliable vibration responses is to evaluate accurate structural dynamic properties using finite element (FE) models, which properly represent the realistic behavior of buildings. In the case of historic masonry buildings, structural damage could also be caused by ambient vibrations or impacts. Therefore, the preservation plans of historic buildings for low-level vibrations or impacts should be provided by analyzing structural damages within serviceability levels. For this purpose, it is required to provide FE model construction and response analysis methods verified with field measurement data. In this research, long-term field measurement was performed for a cathedral and its dynamic properties were evaluated using measured data. Then, the model was calibrated based on the measured dynamic properties and an overall construction method for the masonry cathedral was proposed. Using the measured accelerations, the vibrations of the belfry were analyzed using the calibrated FE model and finally, the FE model for the cathedral was verified by comparing the measured accelerations with the modeled results.

Influence of loading rate on flexural performance and acoustic emission characteristics of Ultra High Performance Concrete

  • Prabhat Ranjan Prem;Vignesh Kumar Ramamurthy;Vaibhav Vinod Ingle;Darssni Ravichandran;Greeshma Giridhar
    • Structural Engineering and Mechanics
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    • v.89 no.6
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    • pp.617-626
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    • 2024
  • The study investigated the behavior of plain and fibered Ultra-High Performance Concrete (UHPC) beams under varying loading conditions using integrated analysis of the flexure and acoustic emission tests. The loading rate of testing is -0.25 -2 mm/min. It is observed that on increasing loading rate, flexural strength increases, and toughness decreases. The acoustic emission testing revealed that higher loading rates accelerate crack propagation. Fiber effect and matrix cracking are identified as significant contributors to the release of acoustic emission energy, with fiber rupture/failure and matrix cracking showing rate-dependent behavior. Crack classification analysis indicated that the rise angle (RA) value decreased under quasi-static loading. The average frequency (AF) value increased with the loading rate, but this trend reversed under rate-dependent conditions. K-means analysis identified distinct clusters of crack types with unique frequency and duration characteristics at different loading rates. Furthermore, the historic index and signal strength decreased with increasing loading rate after peak capacity, while the severity index increased in the post-peak zone, indicating more severe damage. The sudden rise in the historic index and cumulative signal strength indicates the possibility of several occurrences, such as the emergence of a significant crack, shifts in cracking modes, abrupt failure, or notable fiber debonding/pull-out. Moreover, there is a distinct rise in the number of AE knees corresponding to the increase in loading rate. The crack mapping from acoustic emission testing aligned with observed failure patterns, validating its use in structural health monitoring.

Dynamics of Slender Rigid Blocks Mounted on the Seismic Isolation System (격리받침 위에 놓인 Slender 강체 블록의 동적거동)

  • 김재관
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.10a
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    • pp.448-454
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    • 2000
  • Piled multi-block system has been frequently adopted in the historic structures or monuments of cultural heritage. It is well known that such a structural system is very vulnerable to the earthquake shaking. If the structure is of slender type, then it may experience overturning at very low level intensity of ground shaking. One of the methods used to protect such structures from earthquake is seismic isolation system. But the behavior of multi-block systems mounted on the isolated basis is not well understood yet. In this paper we investigate the dynamic behavior of single slender rigid block mounted on the three different isolation systems, i.e., P-F system, FPS and LRB system. Sliding at the isolation interface of P-F system and FPS is formulated based on Coulomb friction. The mounted single block is assumed undergoing rocking or sticking only. Impacting of a single block is described using distinct element method (DEM). Free vibrations due to a prescribed initial conditions are studied. Responses to the harmonic excitation and earthquake motions are calculated

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Topography of Religion and National, Social & Economic Movements in Chonnam Yeonggwang before and after the 1910's (1910년대 전후 전남 영광지역의 종교지형과 민족사회·경제운동)

  • Kim, Min-Young
    • The Journal of Korean-Japanese National Studies
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    • no.34
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    • pp.5-40
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    • 2018
  • This paper is to take note of national, social and economic movement, social & economic publicness of religion surrounding Yeonggwang, Joennam around 1910s. At first I would like to look at this period because regional society was in the middle of change of large transition before and after Japan's forced occupation of Korea in 1910s and March 1st Independence Movement in 1919. In particular we focus on spatially Yeonggwang in Joennam because this area is not only called as advent area of Buddhism earlier but also is unique regional culture and ideological topology where Donghak, Protestantism, Catholic, Institute of Won Buddhism and etc. Through casting light upon the above, it is expected to offer one clue for the question of internalizing value to be sought for in the national and social and economic movement by Korean religion around 1910 and public goods in the strategy and tactics to be selected and further publicness and practice lying in their awareness and behavior. In particular it is thought to have advanced the accumulation of case study of Yeonggwang in Joennam with representative 'place-ness' related to this. Along with this it is considered that our challenge is to restore and casting light again on common foundation of existence shape and publicness of various religions in the middle of national and social movement and economic movement in Yeonggwang of Joennam area. In other words, we expect that religions will continue individual efforts and common practices to urge social justice for historic and public value based on common good encompassing historic value, in other words, individual responsibility and social justice among social and economic conditions originated from Japanese colonial era.

The Relationship between the Natural Resources and Tourism & Recreational Activities (자연자원과 관광레크레이션활동과의 관계)

  • 박구원;송태갑
    • Journal of Environmental Science International
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    • v.11 no.9
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    • pp.843-849
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    • 2002
  • According to tourism resources in Kyonggi province, tourist behavior was dramatically different in that tourists utilizing natural resources were mainly interested in static tourism activities and sight seeing activities while tourist using socio-cultural resources preferred with dynamic tourism activities and relaxation tourism. Therefore, the objectives of reconstruction should be adjusted depending on types of tourism resources (i.e. natural and socio-cultural resources) or natural intensity as well as the development goal of recreational tourism. In contrast, historic and cultural resources surrounded with natural resources showed higher revisit rate, and was conceived as better touring site than individual resource because of historical people, traditional custom, natural sight seeing, etc. Therefore, it is believed that proper utilization of natural resources will increase revisit rate and create new conception as a famous touring site.

Seismic Test of a 1/2 Scale Model of Wood House with Tiled Roof (기와집 1/2 축소 모델의 지진 실험)

  • Ryu, Hyeuk;Kim, Jae-Kwan;Jeon, Bong-Hee;Kim, Byung-Hyun
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.362-367
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    • 2003
  • To improve the reliability of seismic hazard assessment of historic earthquake, shaking table test of a 1/2 scale model of wood house with tiled roof was performed. Scaled model was constructed through rigorous verification process to have quantitative relationship between the intensity of earthquake and damage state. The completed model was mounted on a shaking table and subjected to the dynamic tests. Two kinds of tests were performed: exploratory test and fragility test. The exploratory test was done with low intensity shaking. In the fragility test, the behavior of the model was carefully monitored while increasing the shaking intensity. The construction details of the model are provided and test procedures are reported. Finally important test results are presented and their implications are discussed.

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Seismic Test of a Full Scale Model of Wood House with Tiled Roof (기와집 실물크기 모델의 지진 실험)

  • Ryu, Hyeuk;Kim, Jae-Kwan;Jeon, Bong-Hee;Kim, Byung-Hyun
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.368-373
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    • 2003
  • To improve the reliability of seismic hazard assessment of historic earthquake, shaking table test of a full scale model of wood house with tiled roof was performed. Full scale model was constructed through rigorous verification process to have quantitative relationship between the intensity of earthquake and damage state. The completed model was mounted on a shaking table and subjected to the dynamic tests. Two kinds of tests were performed: exploratory test and fragility test. The exploratory test was done with low intensity shaking. In the fragility test, the behavior of the model was carefully monitored while increasing the shaking intensity. The construction details of the model are provided and test procedures are reported. Finally important test results are presented and their implications are discussed.

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Seismic Test of a 1/2 Scale Model of Wood House with Thatched Roof (초가집 1/2 축소 모델의 지진 실험)

  • Ryu, Hyeuk;Kim, Jae-Kwan;Huh, Young-Chul;Jeon, Bong-Hee
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.247-252
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    • 2003
  • To improve the reliability of seismic hazard assessment of historic earthquake, shaking table test of a 1/2 scale model of wood house with thatched roof was peformed. Scaled model was constructed through rigorous verification process to have quantitative relationship between the intensity of earthquake and damage state. The completed model was mounted on a shaking table and subjected to the dynamic tests. Two kinds of tests were performed: exploratory test and fragility test. The exploratory test was done with low intensity shaking. In the fragility test, the behavior of the model was carefully monitored while increasing the shaking intensity. The construction details of the model are provided and test procedures are reported. Finally important test results are presented and their implications are discussed.

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Tourists' Historical Image and Behavior Characteristics for Heritage Site at Wolseong Palace in Gyeongju (경주 월성의 역사공간 이미지 및 관광객 이용행태 분석)

  • Kang, Tai-Ho;Park, Joung-Koo;Pan, Xiang;Kim, Sang-Gu
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.29 no.4
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    • pp.148-158
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    • 2011
  • This study examines visitors' image and behavior characteristics of Wolseong palace in Gyeongju. This area has been a royal palace during Silla periods. So many scholars dedicate to the protection of this historical-cultural heritage. The research process consists of two main steps, such as on-site field investigation and survey research. The data were collected in summer and autumn. Collected data is classified into three groups to describe visitors' behavior, time, space, and then processed by statistical methods. The results are as follows: First, there is a shortage of programs and facilities. The result shows most visitors consider Wolseong palace as a pathway for walking. Hence better functions should be developed to attract more visitors but with least effect to historical remains. The founding is that increasing programs for history exploration, enhancing lighting installation, facilities, plant arrangement, road condition and so forth would be suggested.