Existing Building Codes Research Articles

A novel multi-objective generative design approach for sustainable building using multi-task learning (ANN) integration

Building Performance Optimization (BPO) plays a pivotal role in enhancing building performance, guaranteeing comfort while reducing resource consumption. Existing performance-driven generative design is computational demanding and difficult to be generalized to other similar buildings with difficult to be generalized to other building types or climate conditions. To fill this gap, this paper introduces a novel framework, which integrates multitask learning (MTL), code compliance check, and multi-objective optimization through NSGA-III algorithm. This framework is able to identify Paratoo Optimal design solutions, which comply with building codes, at low computation costs. The framework begins with selecting key design variables that are critical to building energy, comfort performance and life cycle cost. It then employs MTL to enhance the model's accuracy while reducing computational costs. Next, we designed a code compliance checking module followed by the NSGA-III optimization process, with the objective of identifying solutions that comply with existing building codes. The results indicate that the proposed MTL network achieved an R2 score of 0.983–0.993 on the test set. In the particular case study where equal weights are preferred, this approach yielded noteworthy reductions of 27.65%, 19.55%, and 31.13% in Building Energy Consumption (BEC), Life Cycle Cost (LCC), and Residue of continuous Daylight Autonomy (RcDA), respectively, for a rural dwelling, and exclude solutions that fail to satisfy regulatory standards. This framework allows designer to input the weights of each objective based on their preference and can be applied to other building types and climate regions. Last, we develop a solution selection tool based on the results output by the framework we proposed, which can be found at https://github.com/LiMingchen159/Village-House-Design-Strategy-in-Hebei-Province-China.

Ductility-related seismic modification factor for CLT shear-wall and glulam moment-resisting frame dual system

The cross-laminated timber (CLT) shear-wall and glulam moment-resisting frame (CLTW–GMRF) dual system is a recently completed research prepared for the British Columbia (BC) Forestry Innovation Investment Ltd. With the introduction of new structural systems, the need to update existing building code becomes evident. Accordingly, this study evaluates the ductility-related force modification factor ( Rd) of the CLTW–GMRF system for the National Building Code of Canada, utilizing the FEMA P-695 procedure. In two performance groups, 16 archetype buildings are designed considering different building storey heights, CLT shear-wall locations, and wall-frame moment proportions. Numerical model of the systems is developed in OpenSees and incremental dynamic analyses are conducted using 30 bi-directional ground motion records that represent the seismicity of Vancouver, BC, Canada. Collapse margin ratios are calculated to assess the adequacy of the trial Rd factors. The research determined that with an over-strength factor of 1.5, an Rd of 3 is found to be acceptable for the system.

Addressing sustainable urban flood risk: reviewing the role and scope of theoretical models and policies

Abstract Contemporary adaptation to urban flooding is based on risk management. Urban planners have both an active role in studying cities and a supportive role in helping to define policies. From 33 case studies, this review tries to give insight into how flood risk management fares in confronting international directives on disaster reduction and sustainability, by defining seven sustainability performance criteria. Most studies try to maximize the acceptability and feasibility of implementing solutions in cities (63.6%) and the revision of existing building codes and plans (51.5%), while fewer try to test existing urban practices for weak points (27.3%). Analyses do not fully consider urban habitats as holistic and complex systems, as citizen awareness (27.3%), costs (21.2%), and biodiversity (24.2%) are some of the least recurring and intersecting themes. The main findings should help planners define new lines of action on urban flooding and consider alternative aspects in their frameworks.

The use and re-use of timber structure elements, within a waste hierarchy concept, as a tool towards circular economy for buildings

Wood is the only natural renewable building material, produced by photosynthesis. It has the ability to preserve the stored carbon in its molecular structure as long as it remains within a structure. Timber dwellings are re-gaining recognition worldwide, especially in remote areas due to their aesthetic superiority, durability and harmony with the natural landscape. Research findings, as well as industrial operations indicate that timber buildings present beneficial environmental impacts, compared to other common building materials. Specifically, timber has substantial strength characteristics, low embodied energy, less CO2 emissions and also an easy and fast construction, combined with minimum disruption to the environment. Moreover, timber buildings have a high potential to reduce waste at site and ability for re-use, when designed for future ease of deconstruction, providing the repeated utilization of the used material, known as, the cascading concept. It is already recognized that successful waste management is a measure towards the containment of climate change. Using timber structures enhances the chances to accomplish the contemporary waste hierarchy concept, which can be implemented according to the application of Design for Deconstruction and Reuse (DfDR) concept, at an early stage. These waste management techniques are strongly related to circular economy, but can only be achieved through the aim of a long-lasting design. Finally, in most countries, the existing building codes should be revised in order to overcome the imposed limitations on the re-use of building materials.

Performance-Based Design of an Irregular RC Structure with and without Supplemental Damping

Many countries are undertaking changes in earthquake design codes, the main reason for it is that the existing building codes do not specify the performance criteria of individual structural elements under various levels of shaking. Even though some buildings performed well in life safety aspects, many of those failed in safeguarding the building from high extent of structural damage under severe shaking. Retrofitting had also proved to be uneconomical for the buildings to perform better under severe shaking. In the current earthquake codes, the displacements and forces are within the elastic limit i.e., the assumed behaviour is linear. But the response of a structure to the major earthquakes is not elastic. There is a high chance of yielding and the development of plastic hinges in the members. Therefore, it is required to perform the non-linear analysis for assessing the inelastic behaviour of the structure. In the present study non-linear static analysis was adopted to assess the seismic performance of an irregular building in plan with re-entrant corners using the capacity spectrum method. If either the drift limit of the structure or the response of the hinges is exceeding the desired level of performance, the structure is fed with supplemental damping to ensure the required performance. It was observed that the formation of hinges crossed life safety level and entered the collapse prevention state. As the response exceeded the desired level of performance a methodology to calculate the required supplemental damping for the structure is proposed. Depending on the level of safety of the structure, an appropriate supplemental damping value can be obtained from the proposed performance plots.

Mathematical model for determining the optimal composition of mortars for restoration of historical monuments

The work covers the compression strength, tensile bending and adhesion of a modified mortar developed by the authors based on local gypsum for the restoration of the Ismail Samani mausoleum and the Kalyan minaret. It has been shown that the strength of the mortar is sufficient and meets the requirements of existing building codes. The recommended compositions of the modified restoration solutions based on gypsum and their strength indicators have been identified. Compositions of modified restoration solutions that contribute to an increase in their water resistance and durability have been studied. In addition, a graphical analysis of the degree of strength of mixtures has been given and mathematical models have been developed. The optimal compositions of mixtures have been determined using mathematical modeling. Based on the results obtained, conclusions have been drawn.

FIRE SAFETY COMPLIANCE AMONG HOSPITAL BUILDINGS: A CASE STUDY FROM NEPAL-ASIA

Purpose: Hospital building is more sensitive to fire as it has large number of patients who might need assistance during evacuation. The assessment focuses to the Compliance for fire safety by accessing different standards; availability of equipment and systems, exit requirements and awareness among the departmental staffs of Hospitals.Design/Methodology/Approach: The study confined to the 4 hospitals from Bharatpur Metropolitan, Nepal based on judgmental sampling viz; Bharatpur Hospital, BP Koirala Memorial Cancer Hospital, College of Medical Science and Chitwan Medical College building. Literature review was done followed by observation with checklist, questionnaire survey and key informant interview.Findings/Result: The study revealed that the fire safety preparedness was not a priority in the hospitals. All hospital buildings were designed following National building codes. Both private and public Hospitals, practically every one of them uncover a similar degree of readiness. Bharatpur hospital lacked many firefighting equipment such as smoke detector, heat detector, fire alarm and water hose reel. Water sprinkle was missed on all hospitals. Obstruction was found in the escape route. Lacked exit signs and floor indications. Staffs were found aware about the general component of the structure like structure plan, area for exit and assembly points but lacked awareness on emergency procedure.Originality/Value: This research complements the existing building code requirements and fire safety implementation especially for hospital building as Nepal is not having specific provisions for hospitals fire safety. It is assumed to be applicable for policy making in concerned authority & forms basis for further research.

Mechanical and durability properties of slag/fly ash based alkali-activated concrete reinforced with steel, polypropylene and polyamide fibers

In this study, mechanical, durability, and microstructural properties of fiber-reinforced slag-fly ash-based alkali-activated concretes were investigated. Polypropylene (PP), steel (ST), and polyamide (PA) fibers were used, and the mechanical properties such as compressive, tensile, and flexural behaviour were investigated. High temperature and freeze-thaw tests were carried out within the scope of durability properties. High-temperature tests were conducted at 300, 600, and 900 degrees. Freeze-thaw tests were applied in 250 cycles. Microstructural analyzes were also carried out to understand the matrix composition of fiber-reinforced slag-fly ash-based alkali-activated concrete. The fibers have improved many mechanical properties, such as tensile and flexural strength. Existing building codes have shown consistent results in predicting the compressive strength of fiber-reinforced alkali-activated concretes at high temperatures. In addition, comparisons were made using existing building codes for splitting tensile strength and flexural strength, and new models were proposed.

Application of Principal Component Analysis Approach to Predict Shear Strength of Reinforced Concrete Beams with Stirrups.

The reinforced concrete (RC) member’s shear strength estimation has been experimentally studied in most cases due to its nonlinear behavior. Many empirical equations have been derived from the experimental data; however, even those adopted in the construction codes do not thoroughly and accurately describe their shear behavior. Theoretically explained equations, on the other hand, are aligned with the experiment; however, they are complicated to use in practice. As shear behavior research is data-driven, the machine learning technique is applicable. Herein, an artificial neural network (ANN) algorithm is trained with 776 experiment results collected from available publications. The raw data is preprocessed by principal component analysis (PCA) before the application of the ANN technique. The predictions of the trained algorithm using ANN with PCA are compared to those of formulae adopted in a few existing building codes. Finally, a parametric study is conducted, and the significance of each variable to the strength of RC members is analyzed.

Factorial Design of Concrete Production in Hot and Warm Humid Zones in South East Nigeria

This study narrates the quality of concrete production as slump wet in warm and hot zones. The quality of concrete mixture is of inevitable concern to all stakeholders in the construction industry in the zones when the climatic conditions of the zones are considered. Absence of National standards, environmental and climatic conditions and other factors are the main factors that affect the quality of concrete produced in the area. The affected mix ratio is examined and all the prevailing construction/production practices are considered. All necessary measures for improving the quality of concrete produced are surveyed considering the relationships between various variables used in the mixture. Three major factors (variables) that are found to be influencing the quality of concrete in the south east, Nigeria. The absence or lack of implementing the existing building code, climatic conditions in the zones and types of construction materials available, all remain the major variable influencing the quality of present concrete production in the zones of south east, Nigeria.

DESIGN AND PERFORMANCE OF HIGH-RISE STRUCTURE USING ULTRA-LIGHTWEIGHT CROSS LAMINATED TIMBER FLOOR SYSTEM

The main objective of this paper is to study the structural performance of a high-rise structure when alternative lightweight material known as cross-laminated timber was used as a slab in floor system in lieu of conventional reinforced concrete slab. A numerical case study was conducted using a highly irregular RC frame building with its two 60-story towers joined at the top. Three major analyses were considered. First, modeling and analyzing the building with an RC slab was conducted to determine the design reference. Second, substituting the RC slab with the CLT slab was performed using the same building skeleton. Third, redesigning and optimizing the building skeleton with that CLT to observe skeleton material saving obtained using the same structural performance criteria. Major lateral loads applicable in the Eastern Province of Saudi Arabia were inputted. Strengths and serviceability requirements for floor diaphragm and lateral load resisting system were checked first before performing a comparative analysis between traditional RC and CLT slabs as floor diaphragm. The structural performance criteria to be used for comparative study between RC and CLT slabs included total drift, inter-story drift due to lateral loads, and base reactions. Structural periods and acceleration responses for each floor were investigated and contrasted with the existing building code. The foundation demand was also investigated based on the structural weight and reactions generated from the RC and CLT floor systems.

Seismic hazard and risk in Bhutan

We present the first modern seismic hazard and risk assessment in the Bhutan Himalaya. We used a fault-based probabilistic seismic hazard analysis based on fault locations, slip-rates, and paleoseismic earthquake data. We worked with two seismic intensity measures: the peak-ground acceleration (PGA) and Modified Mercalli Intensity (MMI). We extend the hazard analysis to risk by using local building distribution data and making various assumptions about building distribution and fragility. We find, unsurprisingly, that the Main Himalayan Thrust (MHT) is the primary source of hazard, with oblique strike-slip faults cutting across and beneath the Himalaya, and extensional grabens on the northern edge of Bhutan a secondary hazard. The hazard is highest in the southern part of Bhutan where the MHT is shallow, and site conditions lead to amplification of shaking. The risk does not reflect the hazard solely, but also the distribution of exposure, which is concentrated in the cities. We also simulated the 1714 MW8 earthquake, producing 10,000 possible shakemaps in terms of PGA and MMI; we find that many locations could experience PGA values of over 1 g, and on average, up to 18% of the Bhutanese population could be affected. Refining the probable frequency of larger events on the MHT in this region, developing local ground motion prediction equations, creating tailored vulnerability models for typical Bhutanese buildings, and improving the exposure mapping would most improve the hazard and risk results shown here. The existing building code of Bhutan, adopted from the Indian Seismic Zonation of 2002 (BIS-1893 in Indian standard criteria for earthquake resistant design of structures, Part 1—General provisions and buildings, New Delhi, 2002), uses a PGA of 0.36 g uniformly applied across the entire country. Our study, however, presents a non-uniform hazard level across the country and thus questions the relevancy of the current code of construction practices in the country.

Evaluation of the seismic performance factors for steel diagrid structural systems using FEMA P-695 and ATC-19 procedures

The diagrid structural systems are mainly used for their structural capabilities and architectural aesthetic possibilities which are provided by the unique geometric configurations of these systems. However, the seismic performance factors of these structural systems are not yet explicitly recommended in the existing building codes. In this study, the seismic performance factors (SPFs) of 6- to 24-story steel diagrid structures are determined considering the post-buckling behavior of diagonal members in compression. Also, the effect of change in span length and the diagonal angles on the SPFs of diagrid structures is studied. The ATC-19 coefficient method is used for calculating the SPFs while FEMA P-695 approach is adopted for evaluating the accuracy of the computed factors. Also, the seismic collapse capacity of these structures considering uncertainties in ground motion, modeling, design, and test data is evaluated based on the FEMA P-695 methodology. The OpenSees software is used for modeling and performing the numerical analyses. The obtained results indicate that by increasing the height of diagrid structures, the over-strength, the response modification factor and the median collapse intensity decrease while the ductility factor increases. It is also concluded that the adjusted collapse margin ratios of the diagrid archetypes are larger than the limits suggested by FEMA P-695.

Seismic Design of Timber Buildings: Highlighted Challenges and Future Trends

Use of timber as a construction material has entered a period of renaissance since the development of high-performance engineered wood products, enabling larger and taller buildings to be built. In addition, due to substantial contribution of the building sector to global energy use, greenhouse gas emissions and waste production, sustainable solutions are needed, for which timber has shown a great potential as a sustainable, resilient and renewable building alternative, not only for single family homes but also for mid-rise and high-rise buildings. Both recent technological developments in timber engineering and exponentially increased use of engineered wood products and wood composites reflect in deficiency of current timber codes and standards. This paper presents an overview of some of the current challenges and emerging trends in the field of seismic design of timber buildings. Currently existing building codes and the development of new generation of European building codes are presented. Ongoing studies on a variety topics within seismic timber engineering are presented, including tall timber and hybrid buildings, composites with timber and seismic retrofitting with timber. Crucial challenges, key research needs and opportunities are addressed and critically discussed.

Façade requirements in the 2021 edition of the US International Building Code

SummaryFollowing the Grenfell Tower tragedy in London, the US requirements for fire safety of façades were revisited. The 2018 edition of the key US regulation, the IBC, had associated shortcomings, in spite of the fact that no US fire losses with fatalities have resulted from complying wall assemblies. This is contained in Chapter 14, Exterior Walls.The key fire test used for exterior assemblies (façades) in the US is a large‐scale test, namely NFPA 285. The test evaluates the vertical and lateral flame‐propagation potential of any exterior wall assembly system with combustible components, typically including insulation. The systems are evaluated as flat specimens containing neither corners nor projections. The “typical” fire scenario modeled corresponds to a fire in a room, venting through a window opening and exposing the exterior wall from both inside and outside. The fire test equipment is a two‐story structure with a test room on each story and a window opening. Two burners expose the test specimen: one is placed inside the ground floor test room and the other one is placed outside, near the window opening. The fire test contains pass/fail criteria based on measuring the following phenomena:• Vertical and lateral flame propagation over the exterior,• Vertical and lateral flame propagation inside the combustible core,• Vertical flame penetration into the second story,• Temperature rise on the exterior and within any wall cavities.The IBC includes requirements for a variety of products and also detailed requirements for three specific assemblies: metal composite materials, high‐pressure decorative exterior‐grade compact laminates, and exterior insulation and finish systems (known in Europe as external thermal insulation composite systems). It also includes requirements for fire‐retardant‐treated wood, water‐resistive barriers, and exterior wall coverings, such as siding and very detailed requirements for foam plastic insulation (as tested on its own and within the assemblies). This work shows multiple changes made when revising the 2018 IBC to the 2021 IBC.Concerns have been expressed regarding the applicability of NFPA 285 to fire scenarios associated with the twin effects of either (a) vertical (such as angled walls) or horizontal (such as balconies) projections or (b) wind. No changes to that effect were made for the 2021 IBC.Three concepts were discussed in detail but not adopted into the code using the “16 ft. parallel panel test” (from FM 4880), either as an alternate or as an additional test, incorporating the effect of wind during the NFPA 285 test and considering the effect of corners and/or projections from flat surface during a modified NFPA 285 test. Also a requirement was incorporated into the International Existing Building Code to conduct an NFPA 285 test when façades are added, replaced, or modified.In summary, this work provides a comprehensive overview of the requirements for façades (both materials and assemblies) in the USA in the presently applicable building code (IBC 2018) and in the next edition (2021) of the applicable building code.

Design of the out-of-plane strengthening of masonry walls with fabric reinforced cementitious matrix composites

Fabric reinforced cementitious matrix (FRCM) composites, made of high strength textiles externally bonded with inorganic matrices, experimentally proved effective to enhance the capacity of masonry walls. With the aim of fostering the transfer of knowledge from scientific research to engineering practice, this paper proposes an approach for the design of the out-of-plane flexural strengthening of masonry walls by FRCM systems. The mechanical properties of the reinforcement are derived by combining the results of tensile tests on textile specimens and FRCM-to-substrate shear bond tests. An expression for the preliminary design of the reinforcement is proposed, according to a limit analysis approach, based on tensile and bond strength of FRCM. Whereas, for structural assessment, strain compatibility is enforced, and the bending moment capacity of the reinforced wall is based on FRCM stiffness, tensile and bond strains, consistently with existing building codes. An estimate of the out-of-plane displacement capacity is also developed, which is particularly useful in seismic assessment. A wide experimental database is used to validate theoretical relationships, tune calibration coefficients and derive safety factors, in accordance with the design-by-testing framework of Eurocode 0 for ultimate limit state design.

Study of the real work of constructions of translucent facade systems

The issues of actual operation of structures, the most common stay-brace-and-cross-beam translucent facade systems used in the fencing of buildings and structures are studied, taking into account the spatial rigidity of the elements of the system. The existing building codes of the Russian Federation, in the absence of specialized methods for calculating such systems, offer static calculation schemes for the supporting frame without taking into account the other elements of the system, including the translucent modules themselves, which do not take into account the behavior of the actual structure and often leads to an increase in the cross section of the bearing elements and their value. Thus, in order to study the actual work and bearing capacity of the structures of translucent facade systems, numerical and experimental tests were carried out with modeling of the actual operating conditions, studies were performed for a fragment of the facade system, the stress-strain state of the system structures was analyzed taking into account their spatial work. Results were obtained on the actual operation of the structures, and behavioral features were revealed under the action of critical forces, which must be taken into account when further calculating and designing such systems.

The Main Changes Made to the Building Codes and Regulations of the “Solar Hot Water Installations” to Increase Energy Efficiency of Projected Solar Power Plants

The progress of work on the revising of building codes and regulations of the “Solar Hot Water Installations”, operating in the territory of the Republic of Uzbekistan is shown. The goal of the work is to create a modified republican regulatory document that meets modern requirements and provides an increase in the energy efficiency of designed solar hot water installations by 30%. The analysis was conducted with domestic and foreign experience in the design, and construction and operation of solar hot water installations for various purposes was studied and summarized. The selection of advanced technical achievements and scientific research of different countries in the field of energy saving and efficient use of solar energy has been carried out. In the process of revising the regulatory document, outdated regulations were excluded; new regulatory requirements were included, taking into account the current level of scientific and technological achievements, design and construction practices, and regional features of the Republic of Uzbekistan. The article introduces and substantiates main changes made to the previously existing building codes and rules, developed on the basis of the analysis of generally accepted results of completed research, development and experimental work, the study and synthesis of domestic and foreign experience in designing, building and operating solar hot water installations for various purposes.

Vibration behaviour of steel-timber composite floors, part (2): Evaluation of human-induced vibrations

The vibration of lightweight floors under service loads may cause annoyance to the occupants of buildings, particularly when the fundamental natural frequency of the floor is close to the range of frequencies 4–8 Hz to which the human body is sensitive. Accordingly, the vibration response of the floors is a governing factor in the structural design of steel-timber composite (STC) flooring systems, which have been proposed as an innovative alternative to conventional steel-concrete floors. The current study is part-2 of a comprehensive experimental and numerical study on serviceability performance of the STC floors under human-induced excitations. Natural frequencies are often used as measure of the acceptable vibration performance of the floors. Accordingly, the finite-element (FE) models calibrated and validated against the experimental results in part-1 are used to predict the natural frequencies of the typical STC floors with medium to long spans, and the effect of the geometry of the floor, the mechanical properties of the connections and the magnitude of superimposed loads on the natural frequencies of the STC floors are investigated through a paramtric study. In addition, dynamic analyses are carried out to predict the vibration response (i.e. displacements, velocities and accelerations) of the STC floors, developed in the parametric study, subject to human activities and the vibration performance of the floors with respect to acceptability criteria derived from various building codes is assessed. Lastly, some floor design recommendations are made to ensure satisfactory performance of the STC floors under human-induced vibrations according to the existing building codes.

The Return of Spatial Dimension into Architecture

The aim of the paper is to explore and establish a base for a possible development of a more holistic and spatially-inclusive method for evaluating energy performance of buildings. This is to be achieved by envisioning building envelopes as arrangements of spatial zones, which could improve the overall energy balance of buildings but at the same time reduce the usage of construction materials and thus consumption of production energy and built-up space. The wall deconstructed in spatial zones, as shown e.g. in Antivilla by Brandlhuber-+, opens a series of questions about the future of existing building codes and certification tools. The potentials are discussed based on the aspects of flexibility, responsiveness, adaptability, replaceability and affordability. The analysis outlines the benefits of the inclusion of those paradigms in the definition of sustainable architecture, and at the same time exposes the lack of possibility to reflect their potential by the established certification criteria. The paper aims at opening the discussion about the limits and traps of quantifying architecture and calls for rethinking of established schemes of sustainability in building sector.