• Title/Summary/Keyword: Allowable load

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The Strength and Applications of OSB Gusset Trusses for Field Assembly (현장조립용 OSB 덧댐판 트러스의 강도 및 활용방안)

  • Kim, Tae-Woo;Ha, Bin;Jang, Sang-Sik
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.6
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    • pp.708-713
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    • 2014
  • Trusses are widely used for wooden houses in the areas where wood construction in generalized for residential housings such as North America, Australian, New Zealand. In Korea, joist and rafter system is generally used because of the production cost, transportation cost and lack of experience required for truss manufacturing. In this study, roof trusses and flat trusses were manufactured by using oriented strand board (OSB) gusset plates for field assembly and tested under bending load to obtain the allowable loads. The allowable load and the actual load of 6m span roof trusses were 10.60 kN and 5.26 kN, respectively, which is regarded to be sufficient for use in construction. The allowable load and the actual load of 6m span floor flat trusses were 7.18 kN and 7.43 kN, respectively. For flat trusses, the allowable load is slightly lower than the actual load but the difference in very small, and it is thought that flat trusses can be used for construction by applying small change of structures and members.

Static load test of the bogie and vibration performance test, dynamic characteristics analysis of the bulk cement car (벌크시멘트화차의 대차 하중시험과 진동성능시험 및 동특성 해석 연구)

  • 홍재성;함영삼;백영남
    • Journal of the Korean Society for Railway
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    • v.6 no.3
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    • pp.186-193
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    • 2003
  • The object of this study is to ensure the stability of bulk cement cars conducting vibration performance test, dynamic characteristic analysis and static load test of bogie frame. In case of static load test, bogie static load test facility was used. In case of dynamic characteristic analysis, Vampire Software was used. In case of vibration performance test, real bulk cement cars were used in kyeung-bu line. In the results of static load test of bogie frame for bulk cement car, all structures satisfied allowable stress criteria of materials. The vibration performance test and dynamic characteristic analysis results satisfied allowable standards.

Case Study on Design Efficiency and Bearing Capacity Characteristics of Bored PHC Piles (PHC 매입말뚝의 설계효율과 지지력 특성 사례분석)

  • Yun, Jung-Mann;Yea, Geu-Guwen;Kim, Hong-Yeon;Choi, Yong-Kyu
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.3
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    • pp.45-53
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    • 2019
  • In this study, it was analyzed the cases of bored PHC piles designed for the building foundations. The overall length of the piles varies within a maximum of 35 m. However, the average length was 17.0 to 18.9 m depending on the kind of the bedrock, with no significant difference. The socket length entered into the bedrock was designed with approximately 58% of the whole piles being 1m, the minimum length of the specification, and up to 5m. Although the range in design efficiency was very large, on average it was about 70%, consistent with the usual known extent. Applications with low design efficiency were mainly shown on the foundation of low-rise buildings or rides with low design load. On the weathered rock, the design load, which governs the design result was widely distributed at 65 to 97% of allowable bearing capacity of ground. The ratio of allowable axial load of piles to allowable bearing capacity of ground is also widely distributed between 36 and 115%, so optimization efforts are required along with design efficiency. On the other hand, the allowable bearing capacity on the soft or hard rock was highly equal, mostly within 90% of the allowable axial load of piles. In the design, the end bearing resistance averaged over 75% of the allowable bearing capacity. However, the results of the dynamic pile load test show that the end bearing resistance was predominant under the E.O.I.D conditions, and in some cases, the end bearing resistance was at least 25% under the restrike conditions.

The Estimation of Bearing Capacity of Auger-drilled Pile in Sand-Gravel by Dynamic Load Test (동재하시험에 의한 모래자갈층에 근입된 매입말뚝의 지지력 산정)

  • Choi, Ki-Chul;Moon, Yu-Ho;Oh, Won-Keun;Chun, Byung-Sik
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1819-1826
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    • 2007
  • This study results of performed field load test in order to estimate the best pile length assessment and allowable bearing capacity of the pile foundation. End of initial driving(EOID) and restrike of pile dynamic loading tests were performed to calculate allowable bearing capacity of the experimental pile side and results were compared with the allowable bearing capacity estimated by theory. The results of allowable bearing capacity by EOID test is $1.08{\sim}1.21$ in the range of compared to the capacity calculated by the Structure Foundation Design Criterion. Allowable bearing Capacity by restrike of pile dynamic loading test is $1.32{\sim}1.48$ in the range of compared to the Structure Foundation Design Criterion. The Foundation Design Criterion underestimated the pile capacity. If the bearing capacity calculated by Structure Foundation Design Criterion is 100, EOID of pile dynamic loading test is 116, restrike of pile dynamic loading test is 138 for 20m pile used in this experimental.

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Prediction of Bending Angle of Bellows and Stability Analysis of Pipeline Using the Prediction (벨로우즈형 신축관이음의 휨각도 예측 및 이를 이용한 배관계의 안정성 해석)

  • Son, In-Soo
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.5
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    • pp.827-833
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    • 2022
  • In this study, the prediction of the bending angle for the 350 A bellows-type expansion joints and the structural stability according to the load were determined. The stability of the 2km piping system was predicted by applying the allowable bending angle of the expansion pipe joint obtained from the analysis. The maximum bending angle was calculated through bending analysis of the bellows-type expansion joints, and the maximum bending angle by numerical calculation was about 1.8°, and the maximum bending angle of the bellows obtained by comparing the allowable strength of the material was about 0. 22°. This angle was very stable compared to the allowable bending angle (3°) of the expansion pipe joint regulation. By applying the maximum bending angle, the allowable maximum deflection of the 2 km pipe was about 3.8 m. When the seismic load was considered using regression analysis, the maximum deflection of the 2km pipe was about 142.3mm, and it was confirmed that the bellows-type expansion joints and the deflection were stable compared to the allowable maximum deflection of the pipe system. These research results are expected to present design and analysis guidelines for the construction of piping and the development of bellows systems, and to be used as basic data for systematic research.

Stability Evaluation of Anchors Using Lift-off Field Test (리프트오프 현장시험을 이용한 앵커의 안정성 평가)

  • Choi, Tae Sic;Yun, Jung Mann;Kim, Yong Seong;You, Seung Kyong;Lee, Kang Il
    • Journal of the Society of Disaster Information
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    • v.17 no.1
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    • pp.128-142
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    • 2021
  • Purpose: This study examines the safety management of anchors that have already been constructed and evaluates the results of lift-off tests conducted at the site. The purpose of the project is to study countermeasures if necessary. Method: Compare the residual load gained after the lift-off test at 36 points behind the site with the preemptive load, allowable load, and design load. We also analyze stability through this and evaluate the stability of anchors. Results and Conclusion: The residual tension at 26 points remained stable. However, the residual load at 10 points was analyzed to be greater than the designed load and less than the allowable load, and it was evaluated as an instability that could cause fracture problems. Therefore, anchors with unstable conditions at 10 points should be monitored and monitored through periodic measurements and quality tests, and the anchor should be observed at the surrounding points as well as the relevant points to maintain stability.

The Behavior of Bearing Capacity for the Precast files (기성말뚝의 지지거동)

  • 박영호
    • Journal of the Korean Geotechnical Society
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    • v.16 no.1
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    • pp.107-116
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    • 2000
  • Dynamic and static load tests are conducted in four construction sites by using steel pipe piles(SPP) and concrete piles to compare differences of load bearing mechanism. Steel pipe piles are instrumented with electric strain gages and are subject to dynamic load tests during driving. The damage of strain gages attached is checked simultaneously. Static load test is also conducted on the same piles after two to seven days' elapse. Then load-settlement behavior and shaft and/or tip resistances are measured. As a result, the allowable bearing capacity calculated by the Davisson's offset method of CAPWAP analysis shows 2~33% larger than that of static load test. The average value of allowable bearing capacity of static load test is closer to the allowable capacity obtained at the safety factor of 2.5 applied on ultimate bearing capacity than to the one obtained from the Davisson's offset method. The analysis of strain gage readings shows that unit skin friction increases with depth. Furthermore, the friction mobilized around the 1~2m above the pile tip considerably contributes to the total shaft resistance.

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A Study on the Vertical Bearing Capacity of Pile using the Maximum Curvature Method (최대곡률 방법을 이용한 말뚝의 연직지지력 연구)

  • 류정수;김석열
    • Geotechnical Engineering
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    • v.11 no.4
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    • pp.5-12
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    • 1995
  • Although the pile Load test provides various informations to predict the bearing capacity of a pile, it has a considerable difficulty of requiring a large amount of weight to enable the test pile to be loaded sufficiently until the yielding or ultimate load is obtained. Many graphical and mathematical methods have been attempted to estimate the bearing capacity from the result of a vertical load test without loading to failure. In the previous work an analytical method to estimate the failure load using the maxi mum curvature which was based on the Southwell's theory was presented by the author. The failure load, as proposed by Crowther, should be defined as the load at which the predefined that criteria are exceeded. The allowable loads by Davisson's method and DIN 4014 were compared with the loads of piles using the maximum curvature, and this paper proposed the allowable load in which the safety factor of the maximum curvature was 2.5. As a result of study, it was reasonable to conclude that the allowable load determined by the maximum curvature method could estimate the vertical bearing capacity from the pile load test without loading to failure.

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