The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Haitham Ayoub - One of the best experts on this subject based on the ideXlab platform.
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Construction live loads on slab formworks before Concrete Placement
Structural Safety, 1994Co-Authors: Saeed Karshenas, Haitham AyoubAbstract:Abstract A description is given of a survey of live loads on slab formworks in multistory Concrete buildings during construction. The survey was conducted during the period 1987 to 1990 and embraced over 22 Concrete building projects in several different cities. In this survey, data were collected on the materials and equipment stored on slab formworks and the worker's load. The live loads supported by slab formworks change continously during construction. This paper studies the live loads on formworks before the Concrete slab is poured. The survey procedure and a statistical analysis of the collected data are presented. The statistical moments of equivalent uniformly distributed loads for formwork member load effects are obtained by using the covariance function developed for the observed live loads and formwork member load effect influence surfaces. A distribution function for formwork member load effects is investigated and fractiles of the calculated equivalent uniformly distributed loads are compared with the current formwork minimum design load recommendations.
Bruce R. Ellingwood - One of the best experts on this subject based on the ideXlab platform.
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Reliability-Based Load Requirements for Formwork Shores during Concrete Placement
Journal of Structural Engineering-asce, 2015Co-Authors: James Reynolds, Kim J.r. Rasmussen, Bruce R. EllingwoodAbstract:AbstractOne challenge in assessing the safety of Concrete formwork supporting structures is the difficulty in predicting the loads on shores. Very limited studies on shore loads are available in the literature. This paper presents the results of a shore load investigation undertaken at three construction sites in Sydney. The study is focused on the vertical loads on shores during and following Concrete Placement. The statistical characteristics of the dead load effect and live load effect are determined. Structural reliability analyses are conducted to evaluate the reliability implications of the allowable stress design and limit state design approaches for shoring structures. An optimal load combination is derived considering the probabilistic characteristics of shore loads.
Saeed Karshenas - One of the best experts on this subject based on the ideXlab platform.
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Dynamic Modeling of Slab Formwork during Concrete Placement
Journal of Structural Engineering, 1994Co-Authors: Saeed Karshenas, Stephen M. HeinrichAbstract:The static and dynamic loads applied to hand‐set slab formworks during the pouring of a Concrete slab are investigated. The spatial distribution and time history of the Concrete‐Placement loads and the resulting formwork response depend on the equipment used for placing the Concrete. The impact loads associated with the crane‐and‐bucket method of Concrete Placement are investigated. A number of factors affect the magnitude of the Concrete load when emptying a bucket. These factors include the height of fall, Concrete slump, bucket‐discharge rate, and the dynamic properties of the slab formwork. A single‐degree‐of‐freedom, variable mass, dynamic model is developed for calculating the Concrete‐Placement loads by taking into consideration the above‐mentioned factors. The Concrete‐flow rate from a bucket is modeled as a lognormal white‐noise random process. To verify the validity of the developed model, several lab experiments were performed using a 2.4m×2.4m(8ft×8ft) formwork deck. The lab's overhead crane w...
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Construction live loads on slab formworks before Concrete Placement
Structural Safety, 1994Co-Authors: Saeed Karshenas, Haitham AyoubAbstract:Abstract A description is given of a survey of live loads on slab formworks in multistory Concrete buildings during construction. The survey was conducted during the period 1987 to 1990 and embraced over 22 Concrete building projects in several different cities. In this survey, data were collected on the materials and equipment stored on slab formworks and the worker's load. The live loads supported by slab formworks change continously during construction. This paper studies the live loads on formworks before the Concrete slab is poured. The survey procedure and a statistical analysis of the collected data are presented. The statistical moments of equivalent uniformly distributed loads for formwork member load effects are obtained by using the covariance function developed for the observed live loads and formwork member load effect influence surfaces. A distribution function for formwork member load effects is investigated and fractiles of the calculated equivalent uniformly distributed loads are compared with the current formwork minimum design load recommendations.
James Reynolds - One of the best experts on this subject based on the ideXlab platform.
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Reliability-Based Load Requirements for Formwork Shores during Concrete Placement
Journal of Structural Engineering-asce, 2015Co-Authors: James Reynolds, Kim J.r. Rasmussen, Bruce R. EllingwoodAbstract:AbstractOne challenge in assessing the safety of Concrete formwork supporting structures is the difficulty in predicting the loads on shores. Very limited studies on shore loads are available in the literature. This paper presents the results of a shore load investigation undertaken at three construction sites in Sydney. The study is focused on the vertical loads on shores during and following Concrete Placement. The statistical characteristics of the dead load effect and live load effect are determined. Structural reliability analyses are conducted to evaluate the reliability implications of the allowable stress design and limit state design approaches for shoring structures. An optimal load combination is derived considering the probabilistic characteristics of shore loads.
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Shore load monitoring during Concrete Placement
Safety Reliability Risk and Life-Cycle Performance of Structures and Infrastructures, 2014Co-Authors: James Reynolds, H Zhang, K RasmussenAbstract:This paper presents the results of a shore load investigation undertaken in three construction sites in Sydney. The actual and theoretical axial loads occurring among shores in scaffold-type formwork supporting systems were determined and compared. In total, ten pour areas were investigated, accumulating valuable data. Both dead and live construction loads were measured prior to, during and post Concrete pour
Kim J.r. Rasmussen - One of the best experts on this subject based on the ideXlab platform.
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Reliability-Based Load Requirements for Formwork Shores during Concrete Placement
Journal of Structural Engineering-asce, 2015Co-Authors: James Reynolds, Kim J.r. Rasmussen, Bruce R. EllingwoodAbstract:AbstractOne challenge in assessing the safety of Concrete formwork supporting structures is the difficulty in predicting the loads on shores. Very limited studies on shore loads are available in the literature. This paper presents the results of a shore load investigation undertaken at three construction sites in Sydney. The study is focused on the vertical loads on shores during and following Concrete Placement. The statistical characteristics of the dead load effect and live load effect are determined. Structural reliability analyses are conducted to evaluate the reliability implications of the allowable stress design and limit state design approaches for shoring structures. An optimal load combination is derived considering the probabilistic characteristics of shore loads.