246 results on '"load distribution"'
Search Results
2. Gravity-Induced Progressive Collapse Response of Precast Corner-Supported Modular Buildings
- Author
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Kamyar Kildashti, Pezhman Sharafi, Hamid Ganji, and Maria Alembagheri
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Gravity (chemistry) ,Visual Arts and Performing Arts ,Computer science ,business.industry ,Load distribution ,Progressive collapse ,Building and Construction ,Structural engineering ,Modular design ,Robustness (computer science) ,Load redistribution ,Precast concrete ,Architecture ,business ,Civil and Structural Engineering ,Connection design - Abstract
Compared with conventional buildings, the design of interconnections in multistory modular buildings requires special attention, due to different load distribution mechanisms, level of red...
- Published
- 2021
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3. Overland Wave Propagation and Load Distribution among Arrays of Elevated Beachfront Structures
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Deniz Velioglu Sogut, Ali Farhadzadeh, and Erdinc Sogut
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010504 meteorology & atmospheric sciences ,Series (mathematics) ,Wave propagation ,Flow (psychology) ,Elevation ,Numerical modeling ,Ocean Engineering ,Load distribution ,Geodesy ,01 natural sciences ,010305 fluids & plasmas ,0103 physical sciences ,Geology ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering - Abstract
A series of laboratory experiments and high-fidelity numerical modeling were conducted to study the effects of the lowest floor elevation on the flow and loading patterns resulting from th...
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- 2020
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4. Experimental and Simulation Studies on the Mechanical Performance of T-Girder Bridge Strengthened with Transverse Connection
- Author
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Chen Chen and Caiqian Yang
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business.industry ,Computer science ,Girder bridge ,Diagonal ,0211 other engineering and technologies ,020101 civil engineering ,Load distribution ,02 engineering and technology ,Building and Construction ,Structural engineering ,Bridge (interpersonal) ,0201 civil engineering ,Connection (mathematics) ,Transverse plane ,021105 building & construction ,Physics::Accelerator Physics ,Safety, Risk, Reliability and Quality ,business ,Civil and Structural Engineering - Abstract
In this paper, a new method is proposed for the strengthening of a T-girder bridge with a transverse connection. The proposed connection consists of a top plate, two diagonal braces, one ho...
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- 2019
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5. Agricultural Vehicle Load Distribution for Timber Bridges
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Chandra Teja Kilaru, Ping Lu, Brent M. Phares, and Junwon Seo
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Engineering ,business.industry ,0211 other engineering and technologies ,020101 civil engineering ,Load distribution ,02 engineering and technology ,Building and Construction ,Civil engineering ,0201 civil engineering ,Transport engineering ,Agriculture ,021105 building & construction ,business ,Civil and Structural Engineering - Published
- 2017
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6. Horizontal Translocation of a High-Rise Building: Case Study
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Tong Guo, Yu Gu, Aiqun Li, and Longwu Wei
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Construction management ,Engineering ,Underpinning ,business.industry ,Foundation (engineering) ,Process (computing) ,Load distribution ,Building and Construction ,Structural engineering ,Building design ,Urban planning ,Rail transportation ,Safety, Risk, Reliability and Quality ,business ,Civil and Structural Engineering - Abstract
This case study presents the horizontal translocation of the Hongxing Mansion, a high-rise building in China, which was moved transversally for 26 m because of modifications in urban planning. The 13-story RC frame-wall structure was built in 2002 with a total height of 63.2 m and a total weight of 109,881 kN, making the project unique as compared with other similar cases. The executive process of this project is introduced, including the initial planning, design, and construction procedures. A load underpinning system was proposed that can transfer the vertical loads uniformly to the rails and distribute the propelling loads from the loaded end to the other end of the building. Anchor-jacked piles were used at the original foundation from the limited indoor clear height so that rails in the original basement can be well supported without the need of large piling machines. A special moving system was proposed and successfully applied, which combined the advantages of pull and push, so that the eff...
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- 2013
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7. Lateral Deflection of Horizontally Loaded Rigid Piles in Elastoplastic Medium
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Ernesto Motta
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Engineering ,business.industry ,Stiffness ,Load distribution ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,Dynamic load testing ,Nonlinear system ,Structural load ,Deflection (engineering) ,medicine ,Lateral deflection ,Geotechnical engineering ,medicine.symptom ,Pile ,business ,General Environmental Science - Abstract
This paper deals with the design of rigid piles under lateral load. In many practical situations pile displacements may be the limiting factor in the design; thus, an allowable displacement analysis instead of an allowable stress analysis may be more appropriate in the foundation design. A nonlinear elastoplastic closed-form solution for the evaluation of the response of rigid piles under lateral load is presented. The derived equations allow determining the lateral displacement and load distribution for a given combination of the applied forces, H0 and M0, at the pile head. The approach can be applied either for cohesive or cohesionless soils. For greater generality, the solution has been given in nondimensional form. A comparison with the Broms solution for a free rigid pile in cohesionless soil is also presented. Comparisons with experimental results show that the proposed approach may fit in a reliable way the nonlinear load-displacement response of a free rigid pile.
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- 2013
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8. Load-Rating Procedures for Railroad Flatcars Repurposed as Sustainable Highway Bridges
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Kadir C. Sener, Robert J. Connor, Amit H. Varma, and Teresa Washeleski
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Sustainable development ,Engineering ,business.industry ,0211 other engineering and technologies ,020101 civil engineering ,Load distribution ,02 engineering and technology ,Building and Construction ,Reinforced concrete ,Civil engineering ,0201 civil engineering ,Deck ,Installation ,021105 building & construction ,Load rating ,business ,Civil and Structural Engineering - Abstract
Many county highway agencies have explored different options for economical replacement of existing deteriorating bridges. Using retired railroad flatcars (RRFCs) as the bridge superstructure is an attractive and sustainable option for some owners with very limited budgets and where traffic volumes are low. Using RRFCs is also environmentally attractive because they are 100% recyclable. Previous research focused on the development of guidelines to address the uncertainty that exists when load rating these types of structures. Those guidelines were based on field testing conducted on existing RRFC bridges. However, questions remain about the response under loads higher than could be easily achieved during the field testing. Further, although most RRFC bridges utilize timber decks or thin plate decks covered in bituminous material, there is evidence suggesting that installing a traditional composite RC deck is actually more economical and greatly improves load distribution. This paper presents the r...
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- 2016
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9. Shaft Capacity of Open-Ended Piles in Clay
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Paul Doherty and Kenneth Gavin
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Engineering ,business.industry ,Effective stress ,Load distribution ,Field tests ,Structural engineering ,Site analysis ,Geotechnical Engineering and Engineering Geology ,Pore water pressure ,Soft clay ,Shear stress ,Geotechnical engineering ,Radial stresses ,business ,Pile ,Instrumentation ,Piles ,Foundations ,Open-ended penetration ,General Environmental Science - Abstract
This paper describes an experimental investigation designed to assess the impact of pile end condition on the capacity of piles installed in soft clay. A series of field tests are described in which instrumented open-ended and closed-ended model piles were jacked into soft clay. The radial stresses, pore pressures, and load distribution were recorded throughout installation, equalization, and load-testing. Although the total stress and pore pressure developed during installation were related to the degree of soil plugging, the radial effective stress that controls the shaft resistance was shown to be independent of the mode of penetration. The long-term shaft capacity of the open-ended pile was closely comparable to that developed by closed-ended piles, suggesting a limited influence of end condition on the fully equalized shaft resistance. In contrast to the shaft resistance, the base capacity was highly dependent on the degree of plugging. Deposited by bulk import RB 19/02/13
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- 2011
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10. Load Configuration and Lateral Distribution of NATO Wheeled Military Trucks for Steel I-Girder Bridges
- Author
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R. Gordon Wight, Yail J. Kim, and Rusmir Tanovic
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Truck ,Engineering ,business.industry ,Load distribution ,Building and Construction ,Structural engineering ,Load factor ,Bridge (nautical) ,Military Engineer ,Axle ,Structural load ,Girder ,business ,Civil and Structural Engineering - Abstract
This paper presents the lateral load distribution of various North Atlantic Treaty Organization (NATO) wheeled military trucks on a simple-span steel I-girder bridge (L=36 m). The military trucks are classified into the military load classification (MLC) system. The MLC trucks demonstrate different load configurations when compared to the standard HS20 truck in terms of wheel-line spacing, number of axles, and weight. A calibrated three-dimensional finite-element analysis is conducted to examine the MLC load effects. The applicability of the AASHTO LRFD provisions is evaluated using 72 different load models. The wheel-line spacing and weight of the MLC trucks cause different flexural behavior and load distributions of the bridge when compared to those of HS20. The current AASHTO LRFD approach to determine live load distribution factors may be reasonably applicable to the MLC trucks, including approximately 20% of conservative predictions.
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- 2010
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11. Workload Distribution Framework for the Parallel Solution of Large Structural Models on Heterogeneous PC Clusters
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Ozgur Kurc
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Engineering ,business.industry ,Cluster (physics) ,Substructure ,Symmetric multiprocessor system ,Load distribution ,Workload ,Parallel computing ,Load balancing (computing) ,business ,Computer Science Applications ,Civil and Structural Engineering ,Subdivision - Abstract
One of the main problems of substructure-based parallel solution methods is the imbalances in the condensation times of substructures when direct solvers are used. Such imbalances usually decrease the performance of the parallel solution. Thus, in this study, a workload distribution framework for such methods at heterogeneous computing environment is presented. The main idea behind this framework is to iteratively adjust the shapes of substructures so that the imbalance in their condensation times is minimized. Both generated and actual structural models were solved to illustrate the applicability and the efficiency of this approach. In these examples, a PC cluster having eight different computers was used.
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- 2010
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12. Behavior of a One-Sixth Scale Wood-Framed Residential Structure under Wave Loading
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Rakesh Gupta, Rachel A. Garcia, Jebediah S. Wilson, John W. van de Lindt, and Milo Clauson
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Engineering ,Scale (ratio) ,business.industry ,Eaves ,Structure (category theory) ,Building model ,Stiffness ,Load distribution ,Building and Construction ,Structural engineering ,Qualitative analysis ,Wave loading ,medicine ,medicine.symptom ,Safety, Risk, Reliability and Quality ,business ,Civil and Structural Engineering - Abstract
The goal of this study was to develop an understanding of the nature of wave loading on a wood-framed scale residential building model for a variety of building configurations and test conditions. Testing was performed on a 1/6th scale two-story wood-framed residential structure. The structure was impacted with waves and tested in both flooded and nonflooded conditions. The measured forces were mainly uplift forces due to wave loading, and resulting overturning moments. The qualitative analysis of the data showed that differences in structural stiffness throughout the structure will cause a different load distribution in the structure, e.g., overhanging eaves above the garage can provide unanticipated loading conditions, water traveling beneath the structure generates predominantly uplift forces, and the effect of waves breaking on or near the structure greatly increases the loading. The ratio of force from the windows closed condition to the windows open condition is approximately 2.5:1.
- Published
- 2009
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13. Recent Advances in Performance Evaluation and Flexural Response of Existing Bridges
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Rusmir Tanovic, Yail J. Kim, and R. Gordon Wight
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Engineering ,Quality assessment ,business.industry ,Load distribution ,Building and Construction ,Research needs ,Structural engineering ,Construction engineering ,Bridge (nautical) ,Flexural strength ,Structural load ,Bolted joint ,Bridge maintenance ,Safety, Risk, Reliability and Quality ,business ,Civil and Structural Engineering - Abstract
This paper presents a comprehensive overview of recent developments in the performance evaluation and flexural response of existing bridges from fundamental concepts to advanced topics. The focus is particularly on the structural evaluation to enhance the quality assessment of constructed bridge superstructures, taking into account a synthesis of the most important contributions to the flexural behavior of existing bridges, such as dynamic responses and lateral load distributions. This state-of-the-art paper provides a critical review of published literature and existing assessment methodologies in conjunction with corresponding analysis techniques, including technical comments on the code provisions. Detailed descriptions of the important parameters influencing flexural responses of existing bridges are discussed, such as the geometric effect, loading configuration, present condition of a bridge, and contribution of secondary structural elements. The review also includes the investigation methodologies, namely, the diagnostic and proof load tests. Finally, the current research needs to further advance the performance evaluation technologies for existing bridge superstructures are recommended.
- Published
- 2009
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14. Progressive Collapse Resistance of Hotel San Diego
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Mehrdad Sasani and Serkan Sagiroglu
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Engineering ,business.industry ,Mechanical Engineering ,Local failure ,Load distribution ,Progressive collapse ,Building and Construction ,Structural engineering ,Reinforced concrete ,Brittleness ,Mechanics of Materials ,Load redistribution ,Bending moment ,General Materials Science ,Geotechnical engineering ,business ,Civil and Structural Engineering - Abstract
Progressive collapse resistance of an actual six-story reinforced concrete frame structure is evaluated following predefined initial damage. The initial damage was caused by the simultaneous explosion (removal) of two adjacent exterior columns, one of which was a corner column. The mechanism of load redistribution and change in column axial forces (strains) are discussed. In the structure studied, the development of bidirectional Vierendeel (frame) action is identified as a major mechanism in redistribution of loads. Through careful instrumentation, the change in the direction of beam bending moments in the vicinity of the removed columns is demonstrated. In general, if such a change in the bending moment direction results in high tensile stress in bottom beam reinforcement at the face of a column, brittle local failure in the absence of proper anchorage can occur. This failure did not take place in this building. The nearly century old structure, without satisfying integrity requirements, resisted progre...
- Published
- 2008
- Full Text
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15. Parapet Strength and Contribution to Live-Load Response for Superload Passages
- Author
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Necip Onder Akinci, Judy Liu, and Mark D. Bowman
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Engineering ,business.industry ,Stiffness ,Load distribution ,Building and Construction ,Structural engineering ,Structural load ,Girder ,medicine ,Bending moment ,Geotechnical engineering ,medicine.symptom ,Parapet ,business ,Civil and Structural Engineering - Abstract
The main objective of this study is to evaluate the effects of parapets on the live-load response of slab-on-girder steel bridges subjected to superload vehicles and the effects of these loads on the parapets. A superload is a special permit truck that exceeds the predefined weight limitation. The presence of parapets can result in reduced girder distribution factors (GDFs) for critical girders, and this reserve strength can be considered for passage of a superload truck. This reduction is investigated, as well as the effects of discontinuous parapets and the capacity of parapets. Two steel bridges with significantly different geometric proportions were analyzed to evaluate the sensitivity of the structure to the effects of parapets. It was found that the GDFs can be decreased by as much as 30%, depending on the stiffness of the girders and the transverse truck position if the parapets are included in the analysis. The axial forces and bending moments resisted by the parapets were compared with the capaci...
- Published
- 2008
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16. Bolted Sleeve Joints for Connecting Pultruded FRP Tubular Components
- Author
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Fu Jia Luo, Yu Bai, Xiao Yang, and Ye Lu
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business.product_category ,Materials science ,business.industry ,Tension (physics) ,Mechanical Engineering ,020101 civil engineering ,Load distribution ,02 engineering and technology ,Building and Construction ,Structural engineering ,Fibre-reinforced plastic ,021001 nanoscience & nanotechnology ,Compression (physics) ,Fastener ,0201 civil engineering ,Cable gland ,Mechanics of Materials ,Pultrusion ,Ceramics and Composites ,Composite material ,0210 nano-technology ,business ,Joint (geology) ,Civil and Structural Engineering - Abstract
This paper investigates bolted sleeve joints for connecting tubular pultruded fiber-reinforced polymer (FRP) sections in tubular structures such as space frames. In the proposed joint, FRP profile and steel connector are telescoped and then clamped by mechanical bolts. Four batches of specimens were prepared and tested under static axial loading (tension and compression). Design parameters, namely the type of fastener (ordinary bolt or blind bolt), member size, and bolt group layout, were selected and examined. During experiments, failure modes, load-displacement and load-strain relationships were recorded to evaluate the joint performance. A staggered pattern within a bolted sleeve joint had a negligible effect on the load distribution compared with a nonstaggered pattern. The study showed that the joint capacity could be optimized effectively by adjusting the joint geometry. When blind bolts are used, a compromise between ease of cavity fixing and joint performance must be noted. Finally, a simp...
- Published
- 2016
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17. Behavior of Concrete-Encased CFST Members under Axial Tension
- Author
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Wu Xu, Zhong Tao, Lin-Hai Han, and Zhi-Bin Wang
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Engineering ,Bond strength ,business.industry ,Tension (physics) ,Mechanical Engineering ,0211 other engineering and technologies ,020101 civil engineering ,Load distribution ,02 engineering and technology ,Building and Construction ,Structural engineering ,Finite element method ,0201 civil engineering ,Core (optical fiber) ,Tensile behavior ,Mechanics of Materials ,021105 building & construction ,Ultimate tensile strength ,Steel tube ,General Materials Science ,business ,Civil and Structural Engineering - Abstract
This paper studies the behavior of concrete-encased concrete-filled steel tube (CFST) members under axial tension. Experimental results of thirteen specimens were reported. The variables in the test were the diameter of the steel tube, bond condition between the inner CFST and outer reinforced concrete (RC) components. Push-out tests were conducted to investigate the bond performance between the inner CFST and outer RC components. A finite element model (FEM) was then developed to perform further analysis on the tensile behavior of the concrete-encased CFST member. The internal load distribution between the inner CFST and outer RC components, the interaction between the core concrete and steel tube, and the interaction between the outer concrete and steel tube were investigated. The core concrete and steel tube worked together well, and the tensile strength of the steel tube was enhanced because of the “composite effect,” while the outer RC component was separated from the inner CFST and thus work...
- Published
- 2016
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18. Assessment of Load Transfer and Load Distribution in Bridges Utilizing FRP Panels
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John J. Myers, Antonio Nanni, Danielle D. Kleinhans, D. D., Kleinhan, J. J., Myer, and Nanni, Antonio
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Truck ,Materials science ,Structural material ,business.industry ,Mechanical Engineering ,Load distribution ,Building and Construction ,Structural engineering ,Fibre-reinforced plastic ,computer.software_genre ,Composite construction ,Load testing ,Mechanics of Materials ,Deflection (engineering) ,Ceramics and Composites ,Composite material ,business ,computer ,Design values ,Civil and Structural Engineering - Abstract
A primary means of demonstrating the feasibility and effectiveness of fiber-reinforced polymer (FRP) composite bridge materials is via in situ bridge load testing. For this study, the prescribed or assumed design factors for each of the study bridges were compared to those exhibited by the performance of the bridge. Specifically, the wheel load distribution factors and impact factors as defined by AASHTO were considered in order to assess the load transfer and distribution in structures utilizing FRP panels. The in situ testing configurations for the study bridges are outlined, including the truck and instrumentation placement to obtain the desired information. Furthermore, comparisons were drawn between the design values for deflection and those experienced by the structures during testing. It was found that although the deflections exhibited by the bridges were well within the design limits, further research is needed to be able to prescribe bridge design factors for FRP panels.
- Published
- 2007
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19. Load Proportion Factors for Metal Railing Systems
- Author
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Kimberly Lammert and Thomas Sputo
- Subjects
Engineering ,Visual Arts and Performing Arts ,business.industry ,Load sharing ,Stiffness ,Load distribution ,Building and Construction ,Structural engineering ,Architecture ,medicine ,medicine.symptom ,business ,Picketing ,Civil and Structural Engineering - Abstract
Computer models of 20 metal railing systems were created and analyzed to determine the lateral distribution of load and the sharing of load between posts in a multispan rail system. Single rail, double rail, triple rail, and picket rail pipe railing systems with two and four continuous spans of 0.9144 m (36 in.), 1.2192 m (48 in.), 1.524 m (60 in.), or 1.8288 m (72 in.) were considered. The resulting distribution of load between the adjacent posts was compared to the design nomograph that currently defines the practice. Trend line equations extracted from this data showed that the different railing types produced varied degrees of load sharing under the same loading conditions. Recommendations for load proportion factors that differ from the current recommendations are provided.
- Published
- 2007
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20. Axle Load Distribution for Mechanistic–Empirical Pavement Design
- Author
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Donn E. Hancher, Kamyar C. Mahboub, and Yuhong Wang
- Subjects
Engineering ,Traffic analysis ,business.industry ,Transportation ,Load distribution ,Structural engineering ,Load factor ,Transport engineering ,Axle ,Distribution (mathematics) ,Empirical research ,Software ,Axle load ,business ,Civil and Structural Engineering - Abstract
Mechanistic.empirical (ME) pavement design often demands default or assumed axle load spectrum data. Using single and tandem axles of the Vehicle Class 9 as examples, this study analyzed the spatial and temporal variations of the load distributions from the long-term pavement performance program traffic database. The study found that both spatial and temporal variations are significant; therefore, it may be questionable to use a single default load distribution factor (LDF) for each axle type of vehicle class in design. However, when conducting cluster analysis, the study found that the large amount of data can be classified into a limited number of clusters, from which multiple load distributions can be developed. These distributions, together with spatial and temporal information, may assist engineers in identifying more accurate load distributions for ME design. Based on trial design results using the mechanistic.empirical pavement design guide software, it was found that different LDFs resulted in months of the difference in predicted pavement lives at the same threshold levels for various types of distresses.
- Published
- 2007
- Full Text
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21. Field Test and 3D FE Modeling of Decked Bulb-Tee Bridges
- Author
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Sanjay Chaudhury, J. Leroy Hulsey, Jason L. Millam, and Zhongguo Ma
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Materials science ,business.industry ,Load distribution ,Building and Construction ,Structural engineering ,Finite element method ,Cable gland ,Structural load ,Shear (geology) ,Girder ,Ultimate tensile strength ,Fe model ,business ,Civil and Structural Engineering - Abstract
This paper summarizes field-testing of eight decked bulb-tee girder bridges as well as development of three-dimensional finite-element (FE) models. Using the calibrated 3D FE models, parametric studies have been performed to study the effect of shear connectors and intermediate diaphragms on live-load distribution and connector forces. It was found that: (1) in all cases studied, the live- load distribution factor (DF) for a single-lane loaded bridge was smaller than one for a double-lane loaded bridge; (2) connector forces caused by wheel loads were not uniform along the longitudinal joint—adding intermediate diaphragms tended to reduce the difference among horizontal shear forces in connectors; (3) the maximum horizontal shear force increased with the increase of the connector spacing—intermediate diaphragms reduced the maximum horizontal shear force in connectors; (4) the maximum vertical shear force and in-plane normal tensile force in connectors do not necessarily increase with the increase of the co...
- Published
- 2007
- Full Text
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22. Sensitivity of Live Load Distribution Factors to Vehicle Spacing
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Jay A. Puckett, Dennis R. Mertz, X. Sharon Huo, Michael D. Patrick, and Mark C Jablin
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Engineering ,Mathematical model ,business.industry ,Load distribution ,Building and Construction ,Structural engineering ,Bridge engineering ,Shear (sheet metal) ,Moment (mathematics) ,Distribution (mathematics) ,Structural load ,Sensitivity (control systems) ,business ,Civil and Structural Engineering - Abstract
Two slab-on-girder bridge superstructures are analyzed using grillage models. Different live load placement configurations are investigated to determine the sensitivity of live load shear and moment to vehicle spacing. Results from both bridges show that the distribution factors are relatively insensitive to vehicle spacing. Therefore significant computational speedups are available when applying vehicle loads on an influence surface with a fixed spacing.
- Published
- 2006
- Full Text
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23. Spatial and Temporal Variations in Axle Load Spectra and Impacts on Pavement Design
- Author
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S. Michelle Baker, Rod E. Turochy, and David H Timm
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Axle ,Data collection ,Road construction ,Forensic engineering ,Environmental science ,Axle load ,Transportation ,Statistical analysis ,Soil science ,Load distribution ,Spatial variability ,Spectral analysis ,Civil and Structural Engineering - Abstract
The distribution of axle loads can vary geographically and seasonally; ignoring these variations may impact the accurate characterization of traffic and ultimately the design thickness of new and rehabilitated pavements. A study of axle load spectra at thirteen sites on rural arterials in Alabama examined the statistical and practical significance of these spatial and temporal differences. In most cases, daily and monthly axle load spectra exhibited statistically significant differences from the composite distributions. Differences between distributions observed at each direction at a site and the site average were statistically significant, as were differences between the distribution at each site and the statewide average. However, in most cases, the resultant impact on pavement thickness design was negligible. At 92% of the study sites, use of the statewide distribution in lieu of site-specific data resulted in no more than a difference of 0.3 for structural number for flexible pavement and a 0.7 inch (1.8 cm) difference in rigid pavement depth; these differences were considered insignificant from a practical perspective.
- Published
- 2005
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24. Discussion on AASHTO LRFD Load Distribution Factors for Slab-on-Girder Bridges
- Author
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C.S. Cai
- Subjects
Engineering ,business.industry ,Load distribution ,Building and Construction ,Structural engineering ,Load factor ,Finite element method ,Arts and Humanities (miscellaneous) ,Structural load ,Girder ,Slab ,Curve fitting ,business ,Civil and Structural Engineering - Abstract
The present study developed a new set of formulas for load distribution factors that are more rational than the current AASHTO LRFD formulas. A formula to quantify the intermediate diaphragm effect on live load distribution was also proposed. Preliminary coefficients of these formulas were obtained from curve fitting either with the values of AASHTO LRFD formulas or with the results from finite element modeling. The load distribution factors predicted with the proposed formulas were compared with those from AASHTO codes, field measurements, and finite element analysis with or without considering the effects of intermediate diaphragms. While the present study was intended to shed some light in developing future AASHTO LRFD design formulas, development of complete load distribution factors is out of the scope of the present study.
- Published
- 2005
- Full Text
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25. Multilevel Formwork Load Distribution with Posttensioned Slabs
- Author
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Stephen L. Kajewski
- Subjects
Engineering ,business.industry ,Strategy and Management ,Load distribution ,Building and Construction ,Structural engineering ,Civil engineering ,Shoring ,Finite element method ,Industrial relations ,Slab ,Formwork ,business ,Design methods ,Analysis method ,Civil and Structural Engineering - Abstract
Formwork and the associated shoring represent a significant proportion of the costs associated with the construction of multilevel concrete structures. To minimize these costs, a limited number of formwork and shoring sets are recycled up the structure as construction progresses, eliminating the need for a new set of formwork and shoring with each new slab. When a slab is posttensioned using draped tendons, slab lift occurs as a portion of the slab self-weight is balanced. The formwork and shores supporting that slab are unloaded by an amount equivalent to the load balanced by the posttensioning. This produces a load distribution through the structure that is inherently different from that of a conventionally reinforced slab. This paper presents two design methods suitable for modeling the multilevel formwork process for posttensioned slabs: A modification to the simplified analysis method and a finite element model-both techniques will be of immediate use by industry practitioners and of interest to researchers examining the load distribution phenomenon. The paper also summarizes the findings of one of only a few research projects in which actual shore loads were monitored during the construction of a multilevel posttensioned building, which is used to validate the proposed design models.
- Published
- 2005
- Full Text
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26. Simplified AASHTO Load and Resistance Factor Design Girder Live Load Distribution in Illinois
- Author
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Salah Y. Khayyat, Daniel H. Tobias, Kevin L. Riechers, Zeyn B. Uzman, and Ralph E. Anderson
- Subjects
Engineering ,business.industry ,Load distribution ,Building and Construction ,Load factor ,Civil engineering ,Bridge (nautical) ,Structural load ,State highway ,Girder ,Factor (programming language) ,Bending moment ,business ,computer ,Civil and Structural Engineering ,computer.programming_language - Abstract
Illinois began full transition to the American Association of State Highway and Transportation Officials load and resistance factor design (LRFD) bridge design specifications from the traditional load factor design code or standard specifications in 2002. To facilitate implementation of the new specification, engineers from the Illinois Department of Transportation undertook a series of investigations. The studies focused on interpretation of LRFD for the design of typical bridges in Illinois and the simplification of its procedures for determination of live load lane distributions to primary superstructure girders. Some important presented results from the conducted investigations are believed not only relevant to bridge design in Illinois, but to other states and jurisdictions which employ or will employ LRFD in the near future. The initial simplifications and interpretations focused on concrete deck-on-steel girder bridges and were subsequently expanded to include concrete deck-on-prestressed concrete ...
- Published
- 2004
- Full Text
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27. Evaluation of AASHTO Live Load and Line Load Distribution Factors for I-Girder Bridge Decks
- Author
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Peter Kocsis
- Subjects
Truck ,Engineering ,business.industry ,Specified load ,Girder bridge ,Load distribution ,Building and Construction ,Structural engineering ,Arts and Humanities (miscellaneous) ,Structural load ,Girder ,Line (text file) ,business ,Civil and Structural Engineering - Abstract
This paper evaluates the American Association of State Highway and Transportation Officials (AASHTO) line load and live load distribution factors. The standard AASHTO formulas for live load in some cases underestimate the live load moments by as much as 40%. The AASHTO distribution of line loads (dividing the loads equally among all girders) results in even larger underestimates of line load distribution, leading to unsafe designs. This paper shows how more reliable distribution factors can be obtained for line loads, AASHTO truck loads, and non-AASHTO live loads. A user-friendly computer program for calculating distribution factors is discussed. A useful concept for analyzing beams of variable section (equivalent girder) is also discussed.
- Published
- 2004
- Full Text
- View/download PDF
28. Nondestructive Evaluation of the I-40 Bridge over the Rio Grande River
- Author
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David V. Jáuregui and Paul J. Barr
- Subjects
Engineering ,business.industry ,Strain measurement ,Load distribution ,Building and Construction ,Bridge (interpersonal) ,Archaeology ,law.invention ,Prestressed concrete ,law ,Nondestructive testing ,Forensic engineering ,Safety, Risk, Reliability and Quality ,business ,Civil and Structural Engineering - Abstract
A nondestructive strength evaluation of the I-40 Bridge over the Rio Grande River in Albuquerque, N.M. was completed for the New Mexico Department of Transportation (NMDOT). The I-40 Bridge is a pr...
- Published
- 2004
- Full Text
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29. New Method for Prediction of Loads in Steel Reinforced Soil Walls
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Tony M. Allen, Dave L. Walters, Wei F. Lee, Richard J. Bathurst, and Robert D. Holtz
- Subjects
Engineering ,business.industry ,Stiffness ,Load distribution ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,Retaining wall ,Load factor ,Stress (mechanics) ,Soil structure ,Soil stabilization ,medicine ,Geotechnical engineering ,Geosynthetics ,medicine.symptom ,business ,General Environmental Science - Abstract
The paper describes a new working stress design methodology introduced by the writers for geosynthetic reinforced soil walls (K-Stiffness Method) that is now extended to steel reinforced soil walls...
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- 2004
- Full Text
- View/download PDF
30. Load Distribution for a Highly Skewed Bridge: Testing and Analysis
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Haoxiong Huang, Harry W. Shenton, and Michael J. Chajes
- Subjects
Engineering ,Structural load ,State highway ,business.industry ,Load distribution ,Building and Construction ,Structural engineering ,Field tests ,business ,Bridge (interpersonal) ,Civil and Structural Engineering - Abstract
The American Association of State Highway and Transportation Officials (AASHTO) specifications provide formulas for determining live load distribution factors for bridges. For load distribution fac...
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- 2004
- Full Text
- View/download PDF
31. Simplified Analysis Method for Micropile Pullout Behavior
- Author
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Anil Misra, Raj Oberoi, Andy Kleiber, and C.-H. Chen
- Subjects
Engineering ,Mathematical model ,business.industry ,Vertical deflection ,Foundation (engineering) ,Model parameters ,Load distribution ,Geotechnical Engineering and Engineering Geology ,Soil structure interaction ,Geotechnical engineering ,business ,Scaling ,Analysis method ,General Environmental Science - Abstract
Micropiles are being applied in foundation rehabilitation projects to enhance the pullout capacity of the existing foundation system and minimize the vertical deflection of the structures. Consequently, the pullout load-displacement behavior is important for the design of micropiles used for the rehabilitation of foundations subjected to pullout. In this paper, we present and evaluate analytical relationships for micropile pullout load-displacement behavior, which explicitly considers the micropile–soil interaction. The analytical relationships are kept simple and accessible to designers by assuming the micropile–soil interface to be elastoplastic. The model parameters are combined into scaling factors and a normalization factor that are found to significantly influence micropile load-displacement behavior. The closed-form analytical relationships are used to study the effect of model parameters on the predicted micropile yield behavior. The micropile load transfer behavior calculated by the model is disc...
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- 2004
- Full Text
- View/download PDF
32. Design Models of Light Frame Wood Buildings under Lateral Loads
- Author
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M. S. Collins, Bo Kasal, Phillip Paevere, and Greg Foliente
- Subjects
Engineering ,Mechanics of Materials ,business.industry ,Mechanical Engineering ,Frame (networking) ,General Materials Science ,Load distribution ,Building and Construction ,Structural engineering ,Full scale test ,business ,Finite element method ,Civil and Structural Engineering - Abstract
In this paper, different methods of lateral force distribution and design are described and compared with the results of experiments on a full-scale woodframe test house, and with a detailed three-...
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- 2004
- Full Text
- View/download PDF
33. Steel Girder Design per AASHTO LRFD Specifications (Part 1)
- Author
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Gregor P. Wollmann
- Subjects
Engineering ,Dependency (UML) ,business.industry ,Steel structures ,Load distribution ,Building and Construction ,Structural engineering ,Design load ,Notation ,Load factor ,Buckling ,Girder ,business ,Civil and Structural Engineering - Abstract
The primary objective of this paper and its companion is to give the practicing engineer tools for quick design of steel and composite girders in flexure and shear and to provide a reference to aid with the transition to the AASHTO LRFD Specifications. The AASHTO equations are presented in a modified form, using newly introduced notation that allows formulation of most of the equations without explicit dependency on the steel strength. Based on these modified equations, charts are developed that help to visualize the sometimes complex design equations and which also may be found useful as design aids for preliminary designs. For noncompact sections the AASHTO equations are expressed consistently in a dual form that emphasizes the distinction between slender and nonslender elements. This is the first of two papers and addresses the design of I-girders for flexure.
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- 2004
- Full Text
- View/download PDF
34. Steel Beam-Column Design: New, Fast, and Practical Approach
- Author
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Abbas Aminmansour
- Subjects
Engineering ,Bending (metalworking) ,business.industry ,Steel structures ,Load distribution ,Building and Construction ,Structural engineering ,Load factor ,Range (mathematics) ,Arts and Humanities (miscellaneous) ,Steel columns ,Rational method ,Beam column ,business ,Civil and Structural Engineering - Abstract
A new approach and tables developed for design of steel beam-columns are presented. The new method, which was adopted by the American Institute of Steel Construction (AISC) and has been included in the third edition of the AISC-LRFD Manual of Steel Construction, is an exact, fast, and rational method for effective design of members subjected to combined axial and bending stresses. Numerical example problems are presented to illustrate effective use of the method and tables. Tables developed cover a wide range of W-sections; however, the general approach applies to all sections. Further, the load and resistance factor design (LRFD) method is used in all discussions and examples presented, but the concepts apply equally to design of beam-columns based on the allowable stress design (ASD) method as well.
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- 2004
- Full Text
- View/download PDF
35. Effect of Live-Load Deflections on Steel Bridge Performance
- Author
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Charles W. Roeder, Karl E. Barth, and Adam Bergman
- Subjects
Background information ,Engineering ,business.industry ,Load distribution ,Survey result ,Building and Construction ,Structural engineering ,Civil engineering ,Bridge engineering ,Computer analysis ,Structural load ,Deflection (engineering) ,Research studies ,business ,Civil and Structural Engineering - Abstract
This paper presents an evaluation of the influence of AASHTO live-load deflection criteria on the performance of steel I-girder bridges. Background information is provided regarding previous research studies focused at understanding the role and suitability of live-load deflection limits on steel bridge design. Further, the results of an extensive survey of state transportation departments regarding the use of these limitations is provided. The results of a computer analysis package developed to evaluate the variability of these survey results are also presented. Last, a series of analyses of existing steel bridges conducted to examine the effects of the live-load deflection limits on typical and damaged bridges to determine the role that these limits play in overall superstructure performance is provided.
- Published
- 2004
- Full Text
- View/download PDF
36. Behavior of a Semiintegral Bridge Abutment under Static and Temperature-Induced Cyclic Loading
- Author
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R. M. Barker, Sami Arsoy, and J. M. Duncan
- Subjects
Engineering ,business.industry ,medicine.medical_treatment ,Load distribution ,Building and Construction ,Expansion joint ,Structural engineering ,Temperature induced ,Bridge engineering ,medicine ,Cyclic loading ,Geotechnical engineering ,Bridge (dentistry) ,business ,Civil and Structural Engineering - Abstract
This paper presents results from an experimental study of semiintegral bridge abutments. Primary aims were to investigate: 1) potential problems with the particular detail tested; 2) rotational characteristics of the semiintegral abutments; and 3) ability of specimens to withstand cyclic loading induced by temperature variations during the expected life of the bridge. 16 experiments were conducted on 3 large-scale specimens. Test results have shown that semiintegral abutments can significantly reduce the moments transferred from the superstructure to the foundation piles. Test results have also shown that semiintegral abutments can tolerate the number of displacement cycles that a bridge will experience during the course of its economic life.
- Published
- 2004
- Full Text
- View/download PDF
37. Volumetric Threshold Shear Strain for Cyclic Settlement
- Author
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Chu-Chung Hsu and Mladen Vucetic
- Subjects
Particle-size distribution ,Strain measurement ,Shear stress ,Load distribution ,Geotechnical engineering ,Direct shear test ,Plasticity ,Geotechnical Engineering and Engineering Geology ,Saturation (chemistry) ,Geology ,Soil mechanics ,General Environmental Science - Abstract
The volumetric cyclic threshold shear strain for cyclic settlement, γtv, is evaluated for seven different sands and clays at different degrees of saturation, S, from the results of 11 Norwegian Geo...
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- 2004
- Full Text
- View/download PDF
38. Understanding Capacity Rating of Bridges from Load Tests
- Author
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Mohsen Shahawy and C.S. Cai
- Subjects
Engineering ,Ideal (set theory) ,business.industry ,Extrapolation ,Load distribution ,Building and Construction ,Structural engineering ,Upper and lower bounds ,Field (computer science) ,Arts and Humanities (miscellaneous) ,Girder ,Bolted joint ,Bearing capacity ,business ,Civil and Structural Engineering - Abstract
The paper discusses a few issues related to capacity rating of existing bridges using field test results. The principles of proof and diagnostic load tests for capacity evaluation are presented through discussing the rating formulas for both tests. The proof load rating is proven a lower bound method. The diagnostic rating is proven the same as linear extrapolation, meaning an upper bound approach in nature. Two different methods used in the literature in calculating load distribution factors are discussed. The two methods are proven theoretically equal in an ideal case, but could be significantly different for field bridges due to the effects of many field factors. To distinguish the two methods, one is defined as load distribution factor ~LDF! and the other as girder distribution factor ~GDF!. An example is used to demonstrate the discussions. The results indicate that, on one hand, the measured LDF, though calculated from measured strains, cannot fully reflect the capacity conditions of field bridges. It reflects only a relative load distribution among girders. On the other hand, the GDF approach may overestimate the bridge capacity, because it includes all the beneficial effects. Some beneficial effects may not be reliable for ultimate capacity and thus need to be removed from the capacity rating.
- Published
- 2003
- Full Text
- View/download PDF
39. Predicting Truck Load Spectra under Weight Limit Changes and Its Application to Steel Bridge Fatigue Assessment
- Author
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Gongkang Fu, Fred Moses, Wassem Dekelbab, and Harry Cohen
- Subjects
Truck ,Engineering ,business.industry ,Load distribution ,Building and Construction ,Structural engineering ,Load factor ,Bridge (nautical) ,Bridge engineering ,Limit (music) ,Spectral analysis ,Bearing capacity ,business ,Civil and Structural Engineering - Abstract
Truck weight-limit regulations have significant influence on truck operating weights. These regulations directly influence loads applied to highway facilities, such as bridges and pavements. Truck ...
- Published
- 2003
- Full Text
- View/download PDF
40. Load-Sharing and Redistribution in a One-Story Woodframe Building
- Author
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Greg Foliente, Phillip Paevere, and Bo Kasal
- Subjects
Engineering ,business.industry ,Mechanical Engineering ,Load sharing ,Load distribution ,Building and Construction ,Structural engineering ,Inelastic response ,Construction industry ,Structural load ,Mechanics of Materials ,Load redistribution ,Shear wall ,General Materials Science ,Redistribution (chemistry) ,Geotechnical engineering ,business ,Civil and Structural Engineering - Abstract
This paper presents the results of a series of experiments on a full-scale one-story L-shaped woodframe house. The major objective of the experiments was to collect data for use in the validation of analytical models, and to examine the load redistribution in a nonsymmetrical light-frame structure under lateral loading. In these experiments, the distribution of the reaction forces underneath the walls, and the displaced shape of the house were measured in detail under static and static-cyclic loading. The experimental results have provided the most detailed picture of the reaction forces beneath a nonsymmetrical light-frame structure under lateral loading ever recorded. It was shown that there is potential for significant sharing and redistribution of applied lateral load, between the main shear walls of a light-frame house under both pseudoelastic and inelastic response conditions. Commonly used techniques for lateral load distribution in light-frame structures do not accommodate redistribution of the loading between the walls in the structure.
- Published
- 2003
- Full Text
- View/download PDF
41. Performance of Long Rectangular Barrettes in Granitic Saprolites
- Author
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G.H. Lei and Charles Wang Wai Ng
- Subjects
Engineering ,Design analysis ,business.industry ,Effective stress ,Excavation ,Load distribution ,Foundation engineering ,Geotechnical Engineering and Engineering Geology ,Building process ,Long period ,Soil properties ,Geotechnical engineering ,business ,General Environmental Science - Abstract
In the last three decades, barrettes, namely, excavated rectangular piles, have been increasingly used as foundations to resist large vertical and significant horizontal loads. Empirical approaches are commonly used for the design analyses of barrettes, due to insufficient understanding of the fundamental behavior of the barrettes. In order to improve current design analysis, the behavior of the shaft resistance of long barrettes (ranging from 36 to 63 m long) under vertical loading is investigated in this paper. Fifteen well-documented and reliable tests on long rectangular barrettes founded in granitic saprolites in Hong Kong are selected for critical review and analysis. A database is compiled from these tests. The writers were heavily involved with the construction, testing, and analysis of three of the 15 barrettes. The barrette shaft resistance is quantitatively analyzed with respect to local displacements, in situ soil properties, and the effective stress principle. In addition, the effects of construction including grouting, construction time, side scraping, and excavation tools on the mobilization of the barrette shaft resistance are also investigated. For the barrettes considered, a minimum local displacement of 20 mm is required to mobilize the side resistance of barrettes fully. Grouting along the shaft of barrettes improves the side resistance. On the contrary, construction time has an adverse effect on the shaft resistance, possibly resulting in 45% reduction in capacity if there is a long period of standing time prior to concreting.
- Published
- 2003
- Full Text
- View/download PDF
42. Load Distribution Factors in Simply Supported Skew Bridges
- Author
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Hasan Mirzabozorg and Ali R. Khaloo
- Subjects
Engineering ,business.industry ,Skew ,Load distribution ,Building and Construction ,Structural engineering ,Span (engineering) ,Skew angle ,Finite element method ,Bridge engineering ,Transverse plane ,Girder ,business ,Civil and Structural Engineering - Abstract
Simply supported bridges consisting of five I-section concrete girders are analyzed using the finite-element method. The main parameters of this study are: girder spacing (1.8–2.7 m), span length (25–35 m), skew angle (0–60°), and different arrangements of internal transverse diaphragms. Results of reliable analysis based on the finite-element method show that, in right bridges, American Association of State Highway and Transportation Officials distribution factors are conservative and in skew bridges, these factors are very conservative.
- Published
- 2003
- Full Text
- View/download PDF
43. Extreme Wind Design of Self-Supported Steel Structures: Critical Review of Related ASCE Publications
- Author
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Mehran Keshavarzian
- Subjects
Engineering ,Traffic signal ,Arts and Humanities (miscellaneous) ,Construction industry ,business.industry ,Steel structures ,Load distribution ,Building and Construction ,Structural engineering ,business ,Highway engineering ,Civil engineering ,Civil and Structural Engineering - Abstract
Depending on the application, self-supported tubular steel pole (cantilever) structures in the United States are designed for extreme wind loadings based on either ASCE 74 (for electric utility applications), ANSI/TIA/EIA 222 (for antenna applications), AASHTO (for highway sign and traffic signal applications), or ASCE 7 (for general applications, such as stadium billboards). This paper compares the margins of safety of self-supported tubular steel structures designed for extreme wind loadings based on ASCE 74, TIA/EIA, AASHTO and ASCE 7. Based on this comparison, a critical review of the ASCE publications and their respective design requirements and safety factors are presented.
- Published
- 2003
- Full Text
- View/download PDF
44. Flexural Performance of Drilled Shafts with Minor Flaws in Stiff Clay
- Author
-
Khaled M. Hassan, Hazem A. Sarhan, and Michael W. O'Neill
- Subjects
Pier ,Engineering ,Deformation (mechanics) ,business.industry ,Load distribution ,Structural engineering ,Field tests ,Geotechnical Engineering and Engineering Geology ,Drilled shaft ,Flexural strength ,Nondestructive testing ,Geotechnical engineering ,business ,General Environmental Science ,Shear capacity - Abstract
Lateral loads are often the primary forces that act on drilled shafts when they support retaining walls, bridge piers, or building foundations. The construction of drilled shafts often inadvertently introduces flaws that are not always detectable with well-performed nondestructive evaluation (NDE) techniques. The effect of such undetectable minor flaws on the lateral-load performance of drilled shafts needs to be assessed and subsequently considered in the design. This paper summarizes a field study that consisted of NDE of six, full-scale drilled shafts with preinstalled voids and lateral-load tests that were performed on the six test shafts. Results from the field study indicated that undetectable (by NDE) void flaws occupying areas of up to 15% of the cross-sectional area of the drilled shaft could reduce free-head shear capacity up to 16%. A subsequent numerical analysis was performed to filter out all variables, other than void flaws, that could affect the lateral-load deformation of drilled shafts. Numerical analysis results validated the field tests measurements. A parametric study of variables affecting the load-deformation behavior of drilled shafts suggests that a reduction in moment capacity of up to 27% is possible with undetected voids present in the shafts that were tested.
- Published
- 2002
- Full Text
- View/download PDF
45. Strengthening and Load Testing of Three Bridges in Boone County, Missouri
- Author
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Antonio Nanni, M. Huck, Renato Parretti, and S. Schiebel
- Subjects
Engineering ,business.industry ,Load distribution ,Building and Construction ,computer.software_genre ,Civil engineering ,Bridge engineering ,Load testing ,Upgrade ,Arts and Humanities (miscellaneous) ,Forensic engineering ,business ,Highway engineering ,computer ,Road traffic ,Civil and Structural Engineering - Abstract
Three bridges in Boone County, Missouri—Brown School Road, Coats Lane, and Creasy Springs Bridges—were selected for strengthening with carbon-fiber-reinforced polymer laminates in both shear and flexure. The objective of the rehabilitation program was to remove the 15-ton load posting that had been imposed on each of the bridges. To verify the results of the upgrade, load tests were performed before and after strengthening on tow of the bridges—Brown School Road and Coats Lane Bridges. This paper presents the procedures followed in the design, installation, and load testing of the bridges. A recommendation regarding the removal of the load posting is made.
- Published
- 2002
- Full Text
- View/download PDF
46. Universal Column Formula
- Author
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Burl E. Dishongh
- Subjects
Engineering ,business.industry ,Design specification ,Load distribution ,Building and Construction ,Structural engineering ,Curvature ,symbols.namesake ,Compressive strength ,Arts and Humanities (miscellaneous) ,Buckling ,Deflection (engineering) ,Euler's formula ,symbols ,business ,Axial symmetry ,Civil and Structural Engineering - Abstract
The relationship among the moment, deflection, and buckling load of a structural member is used to develop an elegantly simple and unique expression referred to as the universal column formula (UCF). The UCF relates critical compressive stress to the entire range of member slenderness values for axially loaded columns with or without minor load eccentricity. The UCF is straightforward in appearance and application, yet it is sufficient to perform any axially loaded timber and steel column analysis and design. The UCF unifies the various formulations of column curves common to the field of structural engineering. Comparisons with the secant formula, the Euler curve, and The National Design Specification for Wood Construction and the AISC Design Specifications for Structural Steel Buildings are presented, and a practical application of the UCF is demonstrated.
- Published
- 2002
- Full Text
- View/download PDF
47. Capacity of Drilled Shafts in Burlington Limestone
- Author
-
Brett Gunnink and Chad Kiehne
- Subjects
Load capacity ,Engineering ,business.industry ,Foundation (engineering) ,Geotechnical engineering ,Load distribution ,Bearing capacity ,Field tests ,Geotechnical Engineering and Engineering Geology ,business ,Load cell ,General Environmental Science - Abstract
Field load tests of three drilled shafts socketed in Burlington limestone were conducted using the Osterberg load cell. The objective of the testing was to compare the load capacities obtained from...
- Published
- 2002
- Full Text
- View/download PDF
48. Wind Pressures on Parapets of Flat Roofs
- Author
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R. Bedair, P. Saathoff, and Ted Stathopoulos
- Subjects
Visual Arts and Performing Arts ,business.industry ,Load distribution ,Building and Construction ,Structural engineering ,Wind direction ,Wind engineering ,Flat roof ,Architecture ,Parapet ,business ,Roof ,Wind tunnel test ,Geology ,Civil and Structural Engineering ,Wind tunnel - Abstract
A wind-tunnel study has been carried out to assess wind pressures acting on parapets, including their top surfaces. Local and area-averaged pressure coefficients were measured on parapets of flat-roof models with a length to height ratio (L/H) of 1:1, 2:1, and 3:1. The results were obtained for full-scale equivalent parapet heights of 1 and 2 m and for wind directions ranging from zero to 315°. The local wind load on the parapet was found to be approximately 30% larger at the windward corner of the building than at the midspan location. Maximum parapet loads for the low building model were approximately 30% larger than those for the cubical model. Parapet height did not significantly affect the peak local load on the parapet except in the corner region, where the inward load (toward the roof) for the 1 m parapet was 25% higher than that for the 2 m parapet.
- Published
- 2002
- Full Text
- View/download PDF
49. Distribution of Wheel Loads on Continuous Steel Spread-Box Girder Bridges
- Author
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Magdy Samaan, John B. Kennedy, and Khaled Sennah
- Subjects
Engineering ,Parametric analysis ,business.industry ,Composite number ,Box girder ,Load distribution ,Building and Construction ,Structural engineering ,Finite element method ,Flexural strength ,Deflection (engineering) ,Geotechnical engineering ,business ,Civil and Structural Engineering ,Parametric statistics - Abstract
Composite concrete-steel spread (multispine) box girder bridges remain one of the most common types constructed. Current design practices in North America recommend few analytical methods for the design of such bridges in simply supported construction. However, the effects of continuous construction have not been dealt with fully. In designing a continuous bridge, it is important to determine the maximum negative and positive stresses, maximum reactions, and shears in the bridge subjected to various loadings. This paper presents an extensive parametric study using a finite-element model in which 60 continuous bridge prototypes of various geometries, each subjected to various loading conditions, are analyzed for the distribution of flexural stresses, deflection, shears, and reactions. The parameters considered in the study are span length, number of spread boxes, and number of lanes. Distribution factors for maximum flexural stresses, deflection, shears, and reactions, suitable for design, are deduced for ...
- Published
- 2002
- Full Text
- View/download PDF
50. Funicular Shapes for Submerged Arches
- Author
-
C. Y. Wang and Chien Ming Wang
- Subjects
Engineering ,business.industry ,Mechanical Engineering ,Hydrostatic pressure ,Arch height ,Load distribution ,Building and Construction ,Structural engineering ,Span (engineering) ,Water depth ,Mechanics of Materials ,General Materials Science ,Arch ,business ,Civil and Structural Engineering - Abstract
This paper is concerned with the determination of the funicular shapes of submerged arches. A universal set of curves is generated, from which the shapes of funicular arches under hydrostatic forces may be extracted. The method of extraction of the funicular arch shape depends on the specified design parameters such as the water depth, arch height, and arch span. More importantly, this study shows that depending on the specification of the design parameters, there may not exist any funicular arch solution or there may be occasions in which there could be more than one funicular arch solution for the problem.
- Published
- 2002
- Full Text
- View/download PDF
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