scholarly journals Research Status on the Collapse Mechanism and Prevention Measures of Mega Composite Structural Systems

2018 ◽  
Vol 175 ◽  
pp. 04008
Author(s):  
Wei Zhang
Keyword(s):  
Composite Structures ◽  
Failure Modes ◽  
Progressive Collapse ◽  
Structural Systems ◽  
Collapse Mechanism ◽  
Research Status ◽  
High Rise ◽  
Collapse Mechanisms ◽  
Verification Methods ◽  
Study Results

Mega composite structural system presents wide application prospects in high-rise and super high-rise buildings. However, research concerning the important issues of the seismic behavior, collapse mechanism, and prevention from progressive collapse for such new structural systems under severe earthquakes is quite limited. This paper will summarize the current research status, followed by the discussions on the collapse and prevention mechanisms of high-rise and super high-rise mega composite structural systems under severe earthquakes, the theoretical basis on progressive collapse mechanisms, numerical simulation techniques, and test methods. The failure modes of high-rise mega composite structures were studied firstly, followed by the collapse mechanisms and the associated criteria and indices. In addition, a new numerical technique for simulating the non-linear structural collapses considering large deformations will be presented, along with the relevant test results. This study shows that analysis method, damage accumulation model, failure criteria, appropriate preventive measures, and improved collapse experimental verification methods are all important seismic design considerations for high-rise and super high-rise mega composite structures. Based on the study results, recommendations for collapse and prevention mechanisms of high-rise buildings are proposed.

scholarly journals Experimental study of the progressive collapse mechanism of excavations retained by cantilever piles

2017 ◽  
Vol 54 (4) ◽  
pp. 574-587 ◽  
Author(s):  
X.S. Cheng ◽  
G. Zheng ◽  
Y. Diao ◽  
T.M. Huang ◽  
C.H. Deng ◽  
...  
Keyword(s):  
Load Transfer ◽  
Progressive Collapse ◽  
Maximum Load ◽  
Influential Factors ◽  
Collapse Mechanism ◽  
Sudden Increase ◽  
Bending Moments ◽  
Transfer Coefficients ◽  
Collapse Mechanisms ◽  
Peak Increase

An increasing number of catastrophic progressive collapses of deep excavations have occurred throughout the world. However, the research on progressive collapse mechanisms is limited. In this paper, two categories of model tests were conducted to investigate the mechanism of partial collapse (sudden failures of certain retaining piles) and progressive collapse. The model test results show that partial collapse can cause a sudden increase in the bending moments of adjacent piles via an arching effect. The load-transfer coefficients are defined to be equal to the peak increase ratios of the maximum bending moments in adjacent piles (peak moments caused by collapse over the values before the collapse). When the maximum load-transfer coefficient is larger than the bearing capacity safety factor of the piles, the partial failure will lead to progressive collapse. The influential factors of the progressive collapse mechanism, such as the partial collapse extent, excavation depth, and capping beam, were also investigated. During progressive collapse, the previous failed pile could cause new stress arching; simultaneously, the soil behind certain nearest intact piles could become loosened and destroy the arch springing of the stress arching, causing the progressive collapse to cease gradually.

Pavements in the sky: the skybridge in tall buildings

2003 ◽  
Vol 7 (3-4) ◽  
pp. 325-332 ◽  
Author(s):  
Antony Wood
Keyword(s):  
Progressive Collapse ◽  
World Trade Center ◽  
Tall Buildings ◽  
Structural Systems ◽  
List Type ◽  
High Rise ◽  
Vertical Evacuation ◽  
Trade Center ◽  
The Uk ◽  
World Trade Center Towers

Since the World Trade Center Towers collapsed in full view of the watching world (FEMA, 2002), the improved safety of tall buildings has become of prime importance globally (Pearson, 2001). International groups such as the UK-based ‘Safety in Tall Buildings Working Group’ (Roberts, 2002), and Arups High Rise (Wainwright, 2002) which are considering these safety implications have made recommendations for improvement in three general areas: structural systems, especially with respect to progressive collapsefire proofing, to structure and fabricevacuation systems, concentrating specifically on vertical evacuation systems such as elevators and stairs.

Research on Numerical Model for Earthquake Induced Progressive Collapse of High-Rise Buildings

2014 ◽  
Vol 716-717 ◽  
pp. 223-226
Author(s):  
Yi Xuan Wang ◽  
Lei Huang
Keyword(s):  
Structural Damage ◽  
Progressive Collapse ◽  
Cell Contact ◽  
Collapse Mechanism ◽  
The Finite Element Method ◽  
Contact Algorithm ◽  
High Rise ◽  
Whole Process ◽  
Collapse Behavior ◽  
Weak Zones

Progressive collapse is defined as the collapse of the whole building due to local weak stories or weak zones. In this paper, collapse should theoretically be avoided for any building under any earthquake, it is necessary to study the collapse behavior of buildings to acquire a better understanding of the collapse mechanism and to find efficient methods to prevent it. The collapse process highly depends on the feature of the whole structural system, so numerical simulation becomes a major method to study it. Based on the finite element method, by selecting the appropriate cell death and cell contact algorithm criterion can better simulate the structure collapsed in an earthquake under the continuity of the whole process of destruction, to help understand the causes and mechanism of structural damage. The real buildings are analyzed to study the failure mechanism of the structure. The models proposed are reasonable to study the seismic collapse mechanism of high-rise buildings.

scholarly journals Sensitivity and Uncertainty Analyses of Human and Organizational Risks in Fire Safety Systems for High-Rise Residential Buildings with Probabilistic T-H-O-Risk Methodology

2021 ◽  
Vol 11 (6) ◽  
pp. 2590
Author(s):  
Samson Tan ◽  
Darryl Weinert ◽  
Paul Joseph ◽  
Khalid Moinuddin
Keyword(s):  
Fire Safety ◽  
Residential Buildings ◽  
Fire Risk ◽  
Regulatory Regime ◽  
High Rise ◽  
Fire Engineering ◽  
Verification Methods ◽  
Uncertainty Analyses ◽  
Risk Methodology ◽  
Probabilistic Risk

Given that existing fire risk models often ignore human and organizational errors (HOEs) ultimately leading to underestimation of risks by as much as 80%, this study employs a technical-human-organizational risk (T-H-O-Risk) methodology to address knowledge gaps in current state-of-the-art probabilistic risk analysis (PRA) for high-rise residential buildings with the following goals: (1) Develop an improved PRA methodology to address concerns that deterministic, fire engineering approaches significantly underestimate safety levels that lead to inaccurate fire safety levels. (2) Enhance existing fire safety verification methods by incorporating probabilistic risk approach and HOEs for (i) a more inclusive view of risk, and (ii) to overcome the deterministic nature of current verification methods. (3) Perform comprehensive sensitivity and uncertainty analyses to address uncertainties in numerical estimates used in fault tree/event trees, Bayesian network and system dynamics and their propagation in a probabilistic model. (4) Quantification of human and organizational risks for high-rise residential buildings which contributes towards a policy agenda in the direction of a sustainable, risk-based regulatory regime. This research contributes to the development of the next-generation building codes and risk assessment methodologies.

scholarly journals Tower Crane Location Optimization for Heavy Unit Lifting in High-Rise Modular Construction

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 121
Author(s):  
Hosang Hyun ◽  
Moonseo Park ◽  
Dowan Lee ◽  
Jeonghoon Lee
Keyword(s):  
Low Cost ◽  
Modular Construction ◽  
Algorithm Optimization ◽  
Location Selection ◽  
Project Completion ◽  
High Rise ◽  
Tower Crane ◽  
Proposed Model ◽  
Study Results ◽  
Crane Selection

Modular construction, which involves unit production in factories and on-site work, has benefits such as low cost, high quality, and short duration, resulting from the controlled factory environment utilized. An efficient tower crane lifting plan ensures successful high-rise modular project completion. For improved efficiency, the lifting plan should minimize the reaching distance of the tower crane, because this distance directly affects the tower crane capacity, which is directly related to crane operation cost. In situations where units are lifted from trailers, the trailer-to-tower crane distance can have a significant impact on the tower crane operation efficiency. However, optimization of this distance to improve efficiency has not been sufficiently considered. This research proposes a genetic algorithm optimization model that suggests optimized tower crane and trailer locations. The case study results show that through the proposed model, the project manager can reflect the optimal location selection and optimal tower crane selection options with minimal cost.

Progressive collapse and robustness of modular high-rise buildings

2021 ◽  
pp. 1-13
Author(s):  
Huu-Tai Thai ◽  
Quang Vu Ho ◽  
Wenqian Li ◽  
Tuan Ngo
Keyword(s):  
Progressive Collapse ◽  
High Rise

Failure Analysis of Composite Structures Using Multiscale Technique

2020 ◽  
Vol 995 ◽  
pp. 209-213
Author(s):  
Young W. Kwon
Keyword(s):  
Composite Structures ◽  
Failure Modes ◽  
Cell Model ◽  
Fibrous Composite ◽  
Failure Criteria ◽  
Multiscale Approach ◽  
Interface Failure ◽  
Fiber Failure ◽  
Strain Rate Effects ◽  
Constituent Material

Failure analyses of laminated fibrous composite structures were conducted using the failure criteria based on a multiscale approach. The failure criteria used the stresses and strains in the fiber and matrix materials, respectively, rather than those smeared values at the lamina level. The failure modes and their respective failure criteria consist of fiber failure, matrix failure and their interface failure explicitly. In order to determine the stresses and strains at the constituent material level (i.e. fiber and matrix materials), analytical expressions were derived using a unit-cell model. This model was used for the multiscale approach for both upscaling and downscaling processes. The failure criteria are applicable to both quasi-static loading as well as dynamic loading with strain rate effects.

Resistance of Reinforced Concrete Frames with Masonry Infill Walls to In-Plane Vertical Loading

2016 ◽  
Vol 711 ◽  
pp. 982-988
Author(s):  
Alex Brodsky ◽  
David Z. Yankelevsky
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Progressive Collapse ◽  
Lateral Loading ◽  
Masonry Walls ◽  
Reinforced Concrete Frame ◽  
Masonry Infill ◽  
Concrete Frame ◽  
Vertical Loading ◽  
Infill Masonry

Numerous studies have been conducted on the in plane behavior of masonry infill walls to lateral loading simulating earthquake action on buildings. The present study is focused on a problem that has almost not been studied regarding the vertical (opposed to lateral) in-plane action on these walls. This may be of concern when a supporting column of a multi-storey reinforced concrete frame with infill masonry walls undergoes a severe damage due to an extreme loading such as a strong earthquake, car impact or military or terror action in proximity to the column. The loss of the supporting column may cause a fully or partly progressive collapse to a bare reinforced concrete frame, without infill masonry walls. The presence of the infill masonry walls may restrain the process and prevent the development of a progressive collapse. The aim of the present study is to test the in-plane composite action of Reinforced Concrete (RC) frames with infill masonry walls under vertical loading through laboratory experiments and evaluate the contributions of infill masonry walls, in an attempt to examine the infill masonry wall added resistance to the bare frame under these circumstances. Preliminary results of laboratory tests that have been conducted on reinforced concrete infilled frames without a support at their end, under monotonic vertical loading along that column axis will be presented. The observed damages and failure modes under vertical loading are clearly different from the already known failure modes observed in the case of lateral loading.

Fiber Composite Strength Modeling With Extension to Life Prediction

2005 ◽  
Vol 128 (1) ◽  
pp. 41-49
Author(s):  
Edward M. Wu ◽  
John L. Kardos
Keyword(s):  
Composite Structures ◽  
Life Prediction ◽  
Failure Modes ◽  
Fiber Composite ◽  
Probability Model ◽  
Load Sharing ◽  
Local Load ◽  
Statistical Parameters ◽  
Composite Strength ◽  
Fiber Manufacturing

This paper focuses on the probability modeling of fiber composite strength, wherein the failure modes are dominated by fiber tensile failures. The probability model is the tri-modal local load-sharing model, which is the Phoenix-Harlow local load-sharing model with the filament failure model extended from one mode to three modes. This model results in increased efficiency in the determination of fiber statistical parameters and in lower cost when applied to (i) quality control in materials (fiber) manufacturing, (ii) materials (fiber) selection and comparison, (iii) accounting for the effect of size scaling in design, and (iv) qualification and certification of critical composite structures that are too large and expensive to test statistically. In addition, possible extensions to proof testing and time-dependent life prediction are discussed and preliminary data are presented.

Study on Selection and Optimization of Vertical Transportation Equipment for High-Rise Construction

2010 ◽  
Vol 168-170 ◽  
pp. 2376-2381
Author(s):  
Xi Jing Qi ◽  
Xiao Hu Zhou ◽  
Ming Liang Song ◽  
Feng Ming Li
Keyword(s):  
Project Management ◽  
Evaluation System ◽  
Comprehensive Evaluation ◽  
Close Attention ◽  
Transportation Equipment ◽  
High Rise ◽  
Practical Project ◽  
Study Results ◽  
Objective System ◽  
Comprehensive Evaluation System

High-rise buildings in China has developed rapidly in recent years and problems such as construction and vertical transportation have been paid close attention more and more by society. The safety project management objective system mentioned in this article has comprehensively considered the characteristics of high-rise construction and vertical transportation and provided a comprehensive evaluation system for vertical transportation equipment for high-rise construction, which may be used for guiding equipment selection and optimization of equipment use. Meanwhile, the study results are applied in practical project to verify its effectiveness and practicability, so as to guide the enterprises to reasonably select and use vertical transportation equipment for high-rise construction and to realize the integration benefits of the project.

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