Review on quick safety assessment of building structures in complex urban environment after extreme explosion events

Abstract

Extreme explosion events result in demands for emergency rescue service. From the civil engineering perspective, a quick safety assessment of building structures in the explosion’s vicinity will provide the emergency rescue committee with concrete support to make scientific decisions. In this paper, three primary issues, namely, inverse analysis of explosive characteristics, blast wave propagation in complex urban areas and blast-induced damage identification, are reviewed. These are often performed stepwise and form a multi-step whole to assist the emergency rescue service. The paper begins by introducing the inverse analysis of explosives based on craters, building damages and seismic or acoustic records. In this step, explosive characteristics, for example, charge type, original time, yield and location, could be produced and input into blast load calculation in the next step. Then, the existing literature on blast wave propagation and blast load determination is presented with close attention to complex urban environments. It shows that the current study remains in its infancy and relies on advancement in computational fluid dynamics (CFD). Besides, pressure–impulse (P-I) diagrams which predict the structural damage based on the calculated blast loads are illustrated. Onsite damage detection techniques, such as visual inspection, non-destructive testing (NDT) and vibration-based methods, are also discussed. The paper ends with a discussion of the shortcomings of previous work and the outlooks of further work.

Blast Effects on Hyperloop’s Cylindrical Thin-Shell Structures

“…It reveals that a mesh size larger than 25 mm produces slightly unstable values for stresses, creating inaccurate blast loading results. This is relatively similar to other studies in the area [45][46][47]. However, a mesh element size smaller than 15 mm is an unnecessary value as stress has reached a stable value where convergence time significantly increases.…”

“…Segments are unaware of venting holes for pressure, calculating results in spite of the pressure load acting on other segments. Whilst this characteristic is expected for empirical blast models and acceptable for calculating blast responses [45][46][47], further development using MM-ALE simulations will provide further insight into blast loading and pressure dissipation on hyperloop structures. This will form a part of our future research.…”

The Effect of Scaling Building Configuration Blast Experiments on Positive Phase Blast Wave Parameters

“…While a great deal is known about free-field explosions and their propagation across large distances without the presence of obstacles [8][9][10], research efforts are currently focussed on various built environment aspects as these are far less well understood. These include building geometry in singular structure experiments [11][12][13][14], environmental landscapes [15], protective structures [16,17], and the influence of cities [18][19][20] and street configurations [20,21], for example. For a review of blast wave interaction effects with structures conceptualised as obstacles, the reader is directed to Isaac et al [22], while Radcliff et al [23] contain a comprehensive review of blast loading in urban settings.…”

“…As laboratory studies are usually conducted at a smaller scale than real-life city explosions (for reasons of space availability, cost, and repeatability), the ability to perform small-scale "urban explosion" test cases to validate city-scale predictive modelling would be extremely attractive. Additionally, Shi et al [19] found that a large body of small-scale explosive trials can provide researchers with a reliable understanding of the structure's effects on blast wave propagation. Furthermore, it is important to determine whether these scaling laws are valid for an isolated building outside the areas of well-known blast-facing scenarios prior to tackling the complexities found in cityscapes.…”