• Title/Summary/Keyword: vertical loading

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Evaluation of Lateral Load Resistance Capacity of a High-rise Shear Wall Apartment Based on Elasto-plastic Analaysis (정적 탄소성 해석에 의한 고층 벽식 아파트의 수평내력 검토)

  • 전대한;강호근;조한욱;이정원
    • Journal of the Earthquake Engineering Society of Korea
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    • v.2 no.4
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    • pp.31-40
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    • 1998
  • The purpose of this study is to investigate static elastoplastic behaviour and estimate ultimate resistance capacity of a high-rise apartment shear wall system subjected to a vertical distribution of lateral loading along the height. A typical 25-story two unit plan apartment is selected as a representive model. For the analysis, the pushover analysis is adopted to estimate initial elastic stiffness, post-yielding stiffness and story shear yield resistance level on each story of the structure through three-dimensional nonlinear analysis program-CANNY. In the result of elastoplastic analysis, it is observed that the yield strength of building structures is 1.6 times larger than required lateral design strength.

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Visibility Estimated from the Multi-wavelength Sunphotometer during the Winter 2011 Intensive Observation Period at Seoul, Korea (2011년 겨울철 서울시 대기 집중 관측 기간 동안 다파장 복사계로 분석된 에어러솔 연직분포와 시정 거리)

  • Lee, Kwon-Ho;Kim, Kyung-Won;Kim, Gwanchul;Jung, Kweon;Lee, Soon-Hee
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.5
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    • pp.682-691
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    • 2013
  • The aerosol extinction vertical profile and surface visibility have been derived from the Microtops-II sunphotometer observation during the winter 2011 intensive observation period (IOP) at Seoul, Korea. Using models of degradation of aerosol optical thickness (AOT) and aerosol scale height, we have performed extinction-visibility modulation to determine the height dependent aerosol extinction and visibility. It is shown that the aerosol loading is relatively low during IOP (mean $AOT_{550}=0.22{\pm}0.08$, ${\AA}$ngstr$\ddot{o}$m exponent=$1.14{\pm}0.26$). Modeled extinction by use of Microtops II sunphotometer data shows good agreement with measurements by the Multi-wavelenth Polarization Lidar (MPoLAR), and the derived surface visibility are consistent with data from the transmissometer. These results emphasize the use of a vertically resolved extinction from AOT to predict visibility conditions at ground level.

Estimation of Asphalt Pavement Internal Behavior under Decreasing Truck Speed on Uphill Lanes (오르막 경사구간에서 중차량 속도감소를 고려한 아스팔트 포장구조체 내부거동 분석)

  • Seo, Joowon
    • International Journal of Highway Engineering
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    • v.16 no.2
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    • pp.53-59
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    • 2014
  • PURPOSES : This study estimated an asphalt pavement internal behavior under uphill lanes considering reducing speed of heavy truck on uphill slope. METHODS : Truck performance curve which has been adapted to "Korea Highway Capacity Manual" was analyzed. And asphalt pavement internal behaviors were estimated with Multi-layered elastic analysis using KPRP(Korea Pavement Research Program) dynamic modulus prediction equations. RESULTS : As a result, it is shown that when the standard truck drives 2.0 km at a speed of 80 km/h in 8% climbing slope, it's speed reduced to 25.4 km/h, at same time frequency in asphalt layer decrease to 67.2% and it's dynamic modulus degrades to 30.9%. Based on these results, internal behavior as decreasing vehicle speed on uphill lanes were estimated. CONCLUSIONS : From the results of Multi-layered elastic analysis, internal behavior showed that when the standard truck drives 2.0 km at a speed of 80 km/h in 8% slope on uphill lanes, vertical strain was increased to 44.4% at the bottom of surface course, and lateral tensile strain was increased to 20.5% at the bottom of base course.

A Fundamental Study on Reinforced Soil Slope with Improved Soil Facing (개량토 벽면공을 활용한 보강성토사면에 관한 기초적 연구)

  • Bhang, In-Hwang;Seo, Se-Gwan;Kim, Kwang-Leyol;Kim, You-Seong
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.4
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    • pp.35-44
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    • 2013
  • This paper presents the slope wall technique using soil improvement material for reinforced soil slope through laboratory scale model tests, and verifies the experimental results comparing with numerical analysis. In additional, case study in field has performed to investigate the deformation of reinforced soil slope for 6 months. As a result of laboratory scale model test, numerical analysis, and case study, the reinforcement effect of the slope wall technique using soil improvement material is sufficient to be constructed as reinforced soil slope. The technique shows the stable ratio (0.4%) of horizontal to vertical deformation in the surface loading.

The Study on Dynamic Analysis of Durability of a Wheel using CAE (CAE를 이용한 휠 내구성능 동역학 해석을 위한 연구)

  • Park, Jae Heung;Park, Tae Won;Jung, Sung Pil
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.12
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    • pp.1296-1303
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    • 2012
  • There is a certain limit to reproduce phenomena between the real vehicle and road, since the existing methods to verify durability of the wheel are mostly uni-axial tests. And the change of durability of the wheel can't be predicted since these tests don't consider the camber angle and lateral force as important factors. In this paper, the FE models of the wheel-tire and drum are created. Then, the vertical and lateral loads are applied to wheel-tire assembly and the camber angle is applied by inclining the wheel-tire assembly to the drum. Based on the analysis result, the crack position is predicted to be created in the body of the wheel. The variation of the stress according to the camber angle is verified and the maximum spot of the stress changes continually.

Quantitative Analysis on the Variations of Ground Reaction Force during Ascent and Descent of Bus Stairs in Women

  • Hyun, Seung Hyun;Ryew, Che Cheong
    • Korean Journal of Applied Biomechanics
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    • v.27 no.3
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    • pp.181-187
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    • 2017
  • Objective: The aim of the study was to compare & analyze on the variations of ground reaction force during ascending and descending of bus stair. Method: Simulated wooden stair of bus (raiser: 37.66 cm, width: 109 cm, tread: 29 cm) and GRF system (AMTI-OR-7/ AMTI., USA) was set up within experimental room. Adult female (n=8) performed ascending & descending of simulated bus stair, and variables analyzed consisted of TT (transfer-time), PVF (peak vertical force), LR (loading rate), DR (decay rate), CV (coefficient of variation) and AI (asymmetry index). Sample data from GRF cut off at 1,000 Hz. Results: TT showed shortest variation at phase 1 during descending, but longest variation at phase 1 during ascending of stair. PVF19 (Fz2, 100%) showed large pattern during descending than that of ascending, but rather showed small pattern during ascending of stair in case of PVF2 (Fz4). LR showed larger pattern during descending than that of ascending, but rather during ascending of stair in case of DR. Variation of CV (%) did not show difference between LR and DR, but showed higher possible occurrence of variation during descending of stair. Also AI (%) showed higher index during ascending than that of descending of stair. Conclusion: Because introduction of lowered bus stair has various realistic problems, if lined up at designated bus stopage exactly, rather can solve problems of inconvenience, reduce impulsive force and secure a stability of COG during ascending & descending of stair.

PHOTOELASTIC ANALYSIS OF STRESSES INDUCED BY VARIOUS SUPERSTRUCTURES ON THE ENDOSTEAL IMPLANT (치과 임플랜트 보철 수복시 각 상부구조의 형태에 따라 발생되는 응력의 광탄성학적 분석)

  • Choi Young-Hee;Cho In-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.31 no.4
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    • pp.679-686
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    • 1993
  • The osseointegrated implant conducts the stress directly to the bone due to lack of cushoning effect of periodontal ligament. So, the design and material quality of superstructure plays an important role in resolution and diffusion of stress. Recently, the various superstructures have been developed to improve esthetics and resolve various complicated conditions. The purpose of this study was to evaluate the stress induced by various system on the osseointegrated implant using UCLA abutment, EsthetiCone abutment, Anatomic abutment as well as Branemark conventional abutment. The stress distribution was evaluated by the photoelastic method which can simultaneously observe all around stress distribution. The superstructures embedded in epoxy resin specimen were loaded at various angle with a force of 15Kg to analyse the stress distribution of the fixture. The results of this study were obtained as follows : 1. Under vertical loading, the large and broad stress was distributed below the fixture in all systems. 2. The fringe order of the stress was increased in proportion to tillting the specimen. The largest stress was shown in 25 angled degree tilting case. 3. The Branemark conventional abutment showed the lowest value, and EsthetiCone abutment, Anatomic abutment and UCLA abutment showed the stress value in accending order.

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A Study on the Drainage Effects of Gravel Drain by Laboratory Model Test (실내모형시험을 통한 Gravel Drain의 배수효과에 관한 연구)

  • 천병식;김백영;고용일;여유현;박경원
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.87-94
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    • 1999
  • Sand drain as a vertical drainage is widely used in soft ground improvement. Recently, sand, the principal source of sand drain, is running out. A laboratory model test was carried out to utilize gravel as a substitute for sand. Though which the characteristics of gravel are compared to those of sand for engineering purpose. Two cylindrical containers for the model test were filled with marine clayey soil from the west coast of Korea with a column in the center, one with sand, the other with gravel. Vibrating wire type piezometers were installed at the distance of 1.0D, 1.5D and 2.0D from the center of the column. D is the diameter of the column. The transient process of pore water pressure with loading and the characteristics of consolidation were studied with the data gained from the measuring instrument place on the surface of the container. The parameter study was performed for the marine clayey soil before and after the test in order to check the effectiveness of the improvement. The clogging effect was checked at various depth in gravel column after the test. According to the test, the settlement was found to be smaller in gravel drain than in sand drain. The increase in bearing capacity by gravel pile explains the result. The clogging effect was not found in gravel column. As a result, it is assumed that gravel is relatively acceptable as a drainage material.

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A Case Study on the Application of Gravel Pile in Soft Ground (Gravel Pile에 의한 연약지반 개량 시험시공 사례연구)

  • 천병식;고용일;여유현;김백영;최현석
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.223-230
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    • 2000
  • Sand drain as a vertical drainage is widely used in soft ground improvement. Recently, sand, the principal source of sand drain, is running out. The in-situ tests were carried out to utilize gravel as a substitute for sand. In-situ tests area was divided into two areas by material used. One is Sand Drain(SD) and Sand Compaction Pile(SCP) area, the other is Gravel Drain(GD) and Gravel Compaction Pile(GCP) area. Both areas were monitored to obtain the information on settlement, pore water pressure and bearing capacity by measuring instruments for stage loading caused by embankment. The results of measurements were analyzed, The clogging effect was checked at various depth in gravel column after the test. According to the test results, the settlement was found to be smaller in gravel drain than in sand drain. The increase in bearing capacity by gravel pile explains the result. The clogging effect was not found in gravel column. It is assumed that gravel is relatively acceptable as a drainage material. Gravel is considered to be a better material than sand for bearing capacity, and it is found that bearing capacity is larger when gravel is used as a gravel compaction pile than as a gravel drain.

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Finite element analysis on stress distribution of maxillary implant-retained overdentures depending on the Bar attachment design and palatal coverage

  • Kim, Min-Jeong;Hong, Sung-Ok
    • The Journal of Advanced Prosthodontics
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    • v.8 no.2
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    • pp.85-93
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    • 2016
  • PURPOSE. The purpose of this study was to determine the effect of anchorage systems and palatal coverage of denture base on load transfer in maxillary implant-retained overdenture. MATERIALS AND METHODS. Maxillary implant-retained overdentures with 4 implants placed in the anterior region of edentulous maxilla were converted into a 3-D numerical model, and stress distribution patterns in implant supporting bone in the case of unilateral vertical loading on maxillary right first molar were compared with each other depending on various types of anchorage system and palatal coverage extent of denture base using three-dimensional finite element analysis. RESULTS. In all experimental models, the highest stress was concentrated on the most distal implant and implant supporting bone on loaded side. The stress at the most distal implant-supporting bone was concentrated on the cortical bone. In all anchorage system without palatal coverage of denture base, higher stresses were concentrated on the most distal implant and implant supporting bone on loaded side. CONCLUSION. It could be suggested that when making maxillary implant retained overdenture, using Hader bar instead of milled bar and full palatal coverage rather than partial palatal coverage are more beneficial in distributing the stress that is applied on implant supporting bone.