Review of Tunnel Fire Damage Assessment Methods and Techniques

2021 ◽  
pp. 036119812098722
Author(s):  
Nan Hua ◽  
Negar Elhami-Khorasani ◽  
Anthony Tessari
Keyword(s):  
Numerical Models ◽  
Structural Response ◽  
Concrete Lining ◽  
Future Research ◽  
Fire Damage ◽  
Gas Temperature ◽  
Tunnel Fire ◽  
Emergency Responder ◽  
Fire Scenarios ◽  
Damage In Concrete

Major tunnel fires can have catastrophic consequences, including loss of life, property damage, and long-term service disruptions. The rapid rise of gas temperature in excess of 1,000°C (1,832°F) inside a confined tunnel space as well as long fire duration because of limited emergency responder access necessitate special design considerations when evaluating the structural response to fire. Although tunnel stability is not challenged in most cases, severe damage to the concrete lining is observed after major fire events. This paper provides a detailed review of assessment methodologies and techniques of fire damage in concrete tunnel linings, including guidance on the determination of fire scenarios, concrete spalling, and tunnel safety from existing codes and guidelines, experiments, and numerical models. Based on the review, the need to develop relevant guidelines is emphasized, the knowledge gaps in the existing research are identified, and future research directions are proposed.

scholarly journals Research on Hydroelastic Response of an FMRC Hexagon Enclosed Platform

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1110
Author(s):  
Wei-Qin Liu ◽  
Luo-Nan Xiong ◽  
Guo-Wei Zhang ◽  
Meng Yang ◽  
Wei-Guo Wu ◽  
...  
Keyword(s):  
Time Domain ◽  
Numerical Models ◽  
Structural Response ◽  
Deep Ocean ◽  
Surface Model ◽  
Large Area ◽  
Floating Structure ◽  
Small Depth ◽  
Response Amplitude Operators ◽  
Hydroelastic Response

The numerical hydroelastic method is used to study the structural response of a hexagon enclosed platform (HEP) of flexible module rigid connector (FMRC) structure that can provide life accommodation, ship berthing and marine supply for ships sailing in the deep ocean. Six trapezoidal floating structures constitute the HEP structure so that it is a symmetrical very large floating structure (VLFS). The HEP has the characteristics of large area and small depth, so its hydroelastic response is significant. Therefore, this paper studies the structural responses of a hexagon enclosed platform of FMRC structure in waves by means of a 3D potential-flow hydroelastic method based on modal superposition. Numerical models, including the hydrodynamic model, wet surface model and finite element method (FEM) model, are established, a rigid connection is simulated by many-point-contraction (MPC) and the number of wave cases is determined. The load and structural response of HEP are obtained and analyzed in all wave cases, and frequency-domain hydroelastic calculation and time-domain hydroelastic calculation are carried out. After obtaining a number of response amplitude operators (RAOs) for stress and time-domain stress histories, the mechanism of the HEP structure is compared and analyzed. This study is used to guide engineering design for enclosed-type ocean platforms.

Analysis of the Structural Response of a Mid-span Multi-girder Composite Bridge submitted to different Fire Scenarios

2014 ◽  
Vol 102 (43) ◽  
pp. 71-78
Author(s):  
José Alós Moya ◽  
Ignacio Payá Zaforteza ◽  
Antonio Hospitaler Pérez ◽  
José Aguado López
Keyword(s):  
Structural Response ◽  
Fire Scenarios ◽  
Composite Bridge

scholarly journals Performance of a bridge deck as solar collector in a thermal energy storage system

2020 ◽  
Vol 205 ◽  
pp. 07009
Author(s):  
Di Wu ◽  
Gangqiang Kong ◽  
Hanlong Liu ◽  
Xi Zhu ◽  
Hefu Pu
Keyword(s):  
Wind Speed ◽  
Solar Energy ◽  
Solar Collector ◽  
Bridge Deck ◽  
Collection Efficiency ◽  
Numerical Models ◽  
Storage System ◽  
Structural Response ◽  
Radiation Energy ◽  
Heat Element

Solar energy can be stored in subsurface and extracted to melt snow and deice in winter. In summer, the bridge deck heat element in a bridge deicing system could serve as a solar energy collector without additional cost. Numerical models were developed in this study to investigate the performance of a bridge deck solar collector. The effects of radiation intensity and wind speed on the solar energy collection efficiency of a bridge deck solar energy collector were discussed and analyzed. The results show that the temperature of the slab was decreased during the solar collection process, and the solar energy collection efficiency of the bridge deck solar collector was about 26~47%. The collection efficiency of solar energy at a given wind speed was increased with the decreasing of the radiation energy, and this effect was more pronounced when the wind speed was higher. The solar energy collection was beneficial to the durability of the top asphalt layer as well as the structural response of the bridge because the magnitude and gradient of the slab temperature were much lower when the bridge deck served as a solar energy collector.

Modelling the response of structure-tuned liquid damper systems under large amplitude excitation using SPH

2021 ◽  
pp. 1-31
Author(s):  
Kevin P. McNamara ◽  
Michael J. Tait
Keyword(s):  
Experimental Data ◽  
Large Amplitude ◽  
Numerical Models ◽  
Model Performance ◽  
Structural Response ◽  
System Response ◽  
Tuned Liquid Damper ◽  
Tall Structures ◽  
Incompressible Sph ◽  
Lower Excitation

Abstract The tuned liquid damper (TLD) is a system used to reduce the response of tall structures. Numerical modelling is a very important tool when designing TLDs. Many existing numerical models are capable of accurately capturing the structure-TLD system response at serviceability levels, covering the range where TLDs are primarily intended to perform. However, these models often have convergence issues when considering more extreme structural excitations. The goal of this study is to develop a structure-TLD model without convergence limitations at large amplitude excitations. A structure-TLD numerical model where the TLD is represented by a 2D incompressible SPH scheme is presented. The TLD contains damping screens which are represented by a force term based on the Morison equation. The performance of the model is assessed by comparing to experimental data for a structure-TLD system undergoing large amplitude excitations consisting of four-hour random signals and shorter transient signals. The model shows very good agreement with the experimental data for the structural response. The free surface response of the TLD is captured accurately by the model for the lower excitation forces considered, however as the excitation force is increased there are some discrepancies. The large amplitude excitations also result in SPH fluid particles penetrating the boundaries, resulting in degradation of the model performance over the four-hour simulations. Overall, the model is shown to capture the response of a structure-TLD system undergoing large amplitude excitations well.

Enhancing Emergency Response Management using Emergency Description Information Technology (EDIT)

2016 ◽  
pp. 1264-1278
Author(s):  
Michael A. Erskine ◽  
Will Pepper
Keyword(s):  
Emergency Response ◽  
Process Model ◽  
Large Scale ◽  
Design Science ◽  
Future Research ◽  
Sporting Events ◽  
Emergency Responder ◽  
Response Information ◽  
Novel Approach ◽  
Future Research Directions

This paper presents a novel approach toward facilitating the effective collection and communication of information during an emergency. Initially, this research examines current emergency response information workflows and emergency responder dispatch criteria. A process for the optimization of these workflows and criteria, along with a suggested method to improve data collection accuracy and emergency response time using a mobile device application, are suggested. Specifically, a design-science approach incorporating the development of an expert system designed to facilitate efficient and effective sharing of emergency information is applied. The resulting benefits could improve emergency communications during large-scale international gatherings, such as sporting events or festivals, as well as the sharing of industry-specific safety incidents. A process model for conducting analyses of additional emergency response processes is also presented. Finally, future research directions are discussed.

scholarly journals Numerical Models of Subsurface Flow Constructed Wetlands: Review and Future Development

2020 ◽  
Vol 12 (8) ◽  
pp. 3498
Author(s):  
Chunbo Yuan ◽  
Ting Huang ◽  
Xiaohong Zhao ◽  
Yaqian Zhao
Keyword(s):  
Constructed Wetlands ◽  
Reactive Transport ◽  
Transport Model ◽  
Numerical Models ◽  
Degradation Process ◽  
Research Direction ◽  
Future Research ◽  
Comprehensive Model ◽  
Advantages And Disadvantages ◽  
Model Complex

Numerical model as a simulation tool was used to describe the pollutants transformation and degradation process in constructed wetlands (CWs). It can help provide insight into the “black box” and increase the understanding of the complex processes in CWs. In the last few decades, several process-based numerical models were developed to depict the pollutants removal processes in CWs, which include biochemical model, hydraulic model, reactive-transport model, plants model, clogging model, and coupling model combining two or more sub-models. However, there was a long way to go before fully understanding the decontamination mechanisms of CWs. On the one hand, single or a composite model coupling a small number of sub-models cannot fully reveal the decontamination processes. On the other hand, a comprehensive model including all sub-models of current cognition involves numerous parameters, most of which are interaction and cannot quantitatively determined, thus making the model complex and leading to diffuse interaction. Therefore, in order to describe the reaction processes in CWs more accurately, it is expected that all parameters should be quantified as far as possible in the future model. This study aims to provide a review of the numerical models of CWs and to reveal mechanism of decontamination. Based on the advantages and disadvantages of existing models, the study presented the improvement method and future research direction: (1) new detection/monitoring technique or computing method to quantitatively assess the parameters in CWs models, (2) correcting the simulation errors caused by the assumption of Activated Sludge Models (ASMs) and developing a complete biofilm reaction sub-model, (3) simplification of the comprehensive model, and (4) need of emerging pollutants modeling.

A Brief Review on Numerical Studies on Film Cooling Effectiveness

2016 ◽  
Vol 852 ◽  
pp. 699-706
Author(s):  
Prakhar Jindal ◽  
Shubham Agarwal ◽  
R.P. Sharma
Keyword(s):  
Film Cooling ◽  
Complex Analysis ◽  
Numerical Models ◽  
The Body ◽  
Coolant Fluid ◽  
Future Research ◽  
Cooling Systems ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Trade Offs

Film cooling is employed for effective cooling in nozzles and combustion chambers using a spray of coolant fluid in the mainstream flow to cool the body. Experimental analysis was performed elaborately in the past years to get an exact analysis of film cooling effectiveness with different parameters. This approach was however discouraged due to its high cost and time consumption. Recently, researchers switched to the use of numerical platforms for investigation of complex film cooling systems. The paper discusses in detail the numerical analysis of the film cooling systems done so far and the numerical models employed for such a complex analysis along with the advantages and trade-offs of such a numerical approach. This study was carried out to extend database knowledge about the numerical film cooling for its various applications. Therefore, an appropriate cooling technique should be designed to protect these parts. Film cooling is one of the most effective external cooling methods. Various numerical film cooling techniques presented in the literature have been investigated. Moreover, challenges and future directions of numerical film cooling techniques have been reviewed and presented in this paper. The aim of this review is to summarize recent development in research on film cooling techniques and attempt to identify some challenging issues that need to be solved for future research.

The maximum gas temperature rises beneath the ceiling in a longitudinal ventilated tunnel fire

2021 ◽  
Vol 108 ◽  
pp. 103672
Author(s):  
Yongzheng Yao ◽  
Kun He ◽  
Min Peng ◽  
Long Shi ◽  
Xudong Cheng
Keyword(s):  
Gas Temperature ◽  
Tunnel Fire
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