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On the anniversary of Haiti's devastating quake, Nicholas Ambraseys and Roger Bilham calculate that 83% of all deaths from building collapse in earthquakes over the past 30 years occurred in countries that are anomalously corrupt.

The escalating environmental threat of indoor overheating, exacerbated by global climate change, urbanisation, and population growth, poses a severe risk to public health worldwide, specifically to those regions which are exposed to extreme heat events, such as Australia. This study delves into the critical issue of overheating within residential buildings, examining the existing state of knowledge on overheating criteria and reviewing overheating guidelines embedded in (a) international standards and (b) national building codes. Each regulatory document is analysed based on its underlying thermal comfort model, metric, and indices. The advantages and limitations of each document are practically discussed and for each legislative document and standard, and the quantitative measures have been reviewed, analysed, and summarised. The findings illuminate a global reliance on simplistic indices, such as indoor air temperature and operative temperature, in the existing regulatory documents. However, other critical environmental parameters, such as relative humidity, indoor air velocity, and physiological parameters including metabolic heat production and clothing insulation, are often not included. The absence of mandatory regulations for overheating criteria in residential buildings in some countries, such as in Australian homes, prompts the call for a holistic approach based on a thermal index inclusive of relevant environmental and physiological parameters to quantify heat stress exposure based on human thermal regulation. Gaps and limitations within existing guidelines are identified, and recommendations are proposed to strengthen the regulatory framework for overheating risk assessment in residential buildings. The findings hold significance for policymakers, building energy assessors, architects, and public health professionals, providing direction for the improvement of existing, and development of new, guidelines that aim to enhance indoor thermal condition and population health while ensuring energy efficiency and sustainability in the building stock.

Relationships in ACI 318-14 for calculating the concrete contribution to shear resistance ([V.sub.c]) in reinforced concrete (RC) members (that is, non-prestressed) have been replaced in ACI 318-19 by one general relationship that considers the combined effects of member depth, percentage of longitudinal reinforcement, and the effect of axial stress on predicted shear strength capacity. This new relationship is [V.sub.c] = [(8[[lambda].sub.s][lambda][[[rho].sub.w]].sup.1/3][square root][f'.sub.c] + [N.sub.u]/[6[A.sub.,g]])[b.sub.w]d, where [[lambda].sub.s] is a size effect factor equal to [square root] (2/[1 + d/10])] that accounts for a reduction in shear stress capacity with increasing member depth. The frequently used expression in ACI 318-14, [V.sub.c] = 2[lambda][square root][f.sub.c'bwd], may continue to be used in members containing at least the minimum level of shear reinforcement. The one-way shear provisions for prestressed concrete (PC) members were not changed in this code cycle. The primary basis for the new RC provisions are test results compiled in databases developed and analyzed over the past two decades through a collaboration of Joint ACI-ASCE Committee 445, Shear and Torsion, and the German Committee for Structural Concrete (DAbStb). The process for developing these new provisions included an invitation to the ACI community to suggest new one-way shear design provisions. These suggestions were discussed within Joint ACI-ASCE Committee 445, and then evaluated and modified by ACI Subcommittee 318-E, Section and Member Strength, with consideration of their basis, accuracy, safety, ease-of-use, and range of application. Keywords: building code; database; design; experiments; shear.

A seismic hazard map for the national seismic design code of Pakistan (i.e., Building Code of Pakistan) is derived using probabilistic seismic hazard assessment (PSHA) approach. In order to update the seismic code, an updated seismic zoning map is required that should be based on usage of the recent seismic hazard elements. PSHA of Pakistan is an essential and important milestone. For this purpose, the standard Cornell–McGuire (1968–1976) approach is employed, and the computations are made over a rectangular grid of 0.1°. The main features of this study include usage of a recently compiled earthquake catalogue, recent ground motion prediction equations and an updated seismic source model. The resulting ground motions are obtained as peak ground acceleration (PGA) and 5% damped spectral acceleration (SA) at T = 0.2 s and T = 1.0 s for 475-, 975- and 2475-year return periods (RPs) (evaluated for the flat rock site conditions). Results of the study show that seismic hazard in Pakistan is highest in its central and northern parts. In the central part near Quetta, severe seismic hazard (PGA 0.40 g) is observed. Among the important cities in Pakistan, Balakot city is likely to experience a PGA value of 0.36 g, while Islamabad, Peshawar and Chitral are likely to experience 0.33 g. The cities of Gilgit, Karachi and Gwadar experience ground motion values of 0.34, 0.26 and 0.29 g, respectively, for the 475-year return period (RP). It has also been observed that ground motion values show variation in the distribution and magnitude in contrast to the hazard map of national design code. The hazard map presented in this study is the improved seismic hazard zoning map of Pakistan that would be helpful in developing pre-disaster mitigation strategies and risk assessment studies in Pakistan. It is concluded that the seismic zoning map of the national seismic design code of Pakistan underestimates the ground motion values, and it should be updated or replaced.

Given that less-destructive earthquakes in the developing world have typically cost $3 billion-$10 billion11, earthquake-proof reconstruction in Haiti is likely to cost an order of magnitude more than has been promised so far, even using local materials and local manpower. Because construction projects are likely to offer employment opportunities for many Haitians in the coming decades, earthquake engineers1,13 have already articulated the importance of training contractors and labourers in sound construction methods.

The study presented in this paper aims to assess the recent novelties proposed by new generation building codes about the extension of some concepts at the base of linear analyses to the procedures of nonlinear static analysis. The nonlinear static analysis (pushover) is an extensively adopted approach by engineers and practitioners for purpose of assessing the seismic performance of new and existing buildings, although several drawbacks characterize this methodology, as evidenced by the existing scientific literature. In order to overcome the well-known limitations characterizing nonlinear static analysis, and to offer an alternative to nonlinear dynamic analysis, the recent upgrades of some building codes, such as the Italian one, provide different rules to employ in nonlinear static procedures. Among these new provisions, one regards the possibility to use a horizontal load profile proportional to the storey forces derived from a response spectrum analysis in all cases (i.e., also for irregular buildings). The main goal of this study is to demonstrate the reliability of this new load profile when strong irregularities arise. To this scope, the seismic behaviour of a sample of archetype buildings characterized by increasing in-height irregularity was investigated. The sample of buildings was subdivided in two subsets characterized by different design levels, one conceived by considering the prescriptions of the new Italian building code and one designed according to the oldest Italian building code (i.e., without considering anti-seismic details). The sample of buildings, simulating new and existing cases, was firstly modelled and after investigated through nonlinear static analyses by employing both traditional (i.e., inverse triangular- and uniform-like) and new (i.e., derived from response spectrum analysis) load profiles. After, nonlinear dynamic analyses were run, in order to assess the capacity of both traditional and new load profiles to capture the dynamic behaviour of the investigated archetype buildings. The performed analysis campaign demonstrated the efficiency of the new load profile proposed by the code, and the output of the work provided an answer to the main question posed by the authors: does it make sense to extend the concepts of response spectrum analysis to nonlinear static analysis?

Civil structures are prone to dynamic loadings such as strong winds or ground excitations where torsion becomes an ongoing issue. This arises from a lack of coincidence of the center of mass (CM) and rigidity (CR), known as eccentricity. Seismic design codes often introduce two types of eccentricity: inherent (geometric) and accidental. To account for structural or ground motion uncertainties, an assumption-based solution is provided by many code provisions, which considers the accidental eccentricity as a percentage (5% or 10%) of the building length perpendicular to the direction of exposed ground motion. In this study, as an alternative way to the code design parameters, a new design eccentricity formula that considers the frequency ratio (torsional frequency/translation frequency) and an effective radius of gyration to account for torsional irregularity is considered. For the extended validation of the proposed method, eighteen model buildings with six different floor plans were chosen, representing low, medium-height, and high-rise buildings. Each floor plan had model buildings with three, seven, and twelve stories. The buildings were subjected to selected bidirectional earthquake ground motions and had time history analyses performed. The results of the proposed method were compared to code provision methods, obtained using equivalent lateral force procedures, and also to those obtained utilizing the time history analysis results. It was shown that the proposed method was more effective in estimating the impact of torsional eccentricity and provided a better understanding of its impact on structural dynamic characteristics.

The transition from the Uniform Building Code (UBC-97) to the International Building Code (IBC-21) marked a major shift in the definition of seismic hazard. The term “seismic hazard” in the form of peak ground acceleration (PGA) is replaced by spectral acceleration. This paper investigates the effect of using new seismic hazards on the structural performance of reinforced concrete (RC) buildings. It also looks into the financial impact on the capital costs of new buildings. Useful insights are made to understand the structural performance and financial impact of adopting IBC 21 for structural design in contrast to UBC 97. This study was carried out from the perspective of a developing country, Pakistan. Reinforced concrete moment resisting and dual frames are used as the main structural system of a typical 7-story residential building to investigate the aforementioned effect. The frames are assumed to be located in two locations with high and low seismic hazards. The effect on structural performance is investigated via nonlinear pushover analysis. Financial impact is judged mainly through cost estimation for steel and concrete. A detailed discussion is also presented on the seismic design guidelines in both codes.

Despite the intensity of the 2018 Camp Fire, many structures survived in heavily burned areas. Logistic regressions were run to determine which structural and parcel characteristics predicted structure survival using two data sets. The first, CAL FIRE’s Damage Inspections (DINS) dataset, included 14 518 destroyed and 622 partially damaged structures. The second, combining information from the DINS and Defensible Space (DINS+DSPACE) databases, had many more attributes and was better balanced between destroyed (n = 728) and surviving (n = 676) structures, but was much smaller. Several approaches were compared for filtering out records with null values. Results were largely consistent with previously literature, finding that structural hardness factors (e.g. double-paned windows, enclosed eaves, ignition-resistant roofs and siding, no vents, etc.) are important in determining structure survival. Newer structures, built after California’s recent (2005 and 2007) fire safe building code updates, were more likely to survive, as were homes with higher improvement values. Mobile homes were far more likely to be destroyed. The role of fuel mitigation around structures was less conclusive; defensible space clearance had only a weak association with structure survival, although DINS+DSPACE results suggested a slight reduction in risk due to removing leaves and needles from gutters/roofs and keeping surrounding dead grass mowed.

Buildings are a major contributor to global energy consumption and energy-related carbon dioxide emissions. In light of the climate crisis, changes in the way we design, construct and use buildings are needed to reduce their environmental impact. Green Building Codes (GBCs) and rating systems have been developed around the world as a basis for green building practices. However, several studies raised doubts about the actual performance of certified buildings. Moreover, they use a per unit area approach to assess the use of resources rather than per capita, penalizing small buildings or those with high occupancy, ignoring the concepts of equity and shared common effort which are central to sustainable design. In this paper we propose adjustments to GBCs to encourage new ways of designing and evaluating green buildings. We introduce the Occupancy Correction Factor (OCF) which prioritizes smaller and more densely occupied buildings reducing land use, total operational energy consumption and embodied energy. Results show changes in their energy ratings of one to three levels both up and down, compared to their original ratings. In addition, we propose the prioritization of high-efficiency Low-Energy and Nearly Zero-Energy buildings over Net Zero Energy buildings, encouraging innovative urban design to enhance solar access and electricity production potential on-site or nearby.