National Building Code Research Articles

Lateral Load and Design Disparity between BNBC1993 and BNBC2020

Building codes are the minimal requirements for design and construction to assure a safe and resilient structure. A building code recognized as the Bangladesh National Building Code (BNBC) is existent in Bangladesh (BD), just like in other developing nations. It's now a difficult task to comply with the code because of the extensive update after two decades. The main goal of this work is to compare the analytical and design requirements for lateral loads between BNBC2020 and BNBC1993. To do so, a large number of structural models are assessed using ETABS following the considered code procedure at different locations in the country. It also compares the lateral load parameters such as zone coefficient, wind velocity, building period, story shear, base shear, drift, deflection, reinforcement ratio etc. The parametric comparison of the outcomes has demonstrated that BNBC2020 is more conservative and boosts the safety factor against lateral loads. Engineers will be able to comprehend the differences in lateral load between these codes after perusing this study.

Estimation of historical earthquake-induced liquefaction in Fraser River delta using NBCC 2020 GMPEs in deterministic and probabilistic frameworks

Paleo-liquefaction features of sand dykes and sand blows were identified in the 1990s at multiple host sediments in the Fraser River delta in southern British Columbia all younger than 3500 BP. These paleo-liquefaction sites could be linked to Cascadia subduction earthquakes. Empirical magnitude-bound relationships are often used to estimate paleo-earthquake magnitudes. To determine the lower bound magnitude of Cascadia interface earthquakes that could have generated the paleo-liquefaction features, we use ground motion prediction equations for interface earthquakes from the sixth Canadian seismic hazard model of the 2020 National Building Code of Canada. We estimate the minimum M and its peak ground acceleration ( amax) of an interface earthquake required to initiate paleo-liquefaction in the study region. Starting with three full-rupture deterministic scenarios of varying source-to-site distance, we determine the minimum M required from Cascadia subduction zone interface mega-thrust earthquakes to induce liquefaction in the Fraser River delta spans 8.0–8.9 with a corresponding amax range of 0.09–0.13 g. We also perform a back-calculation paleo-liquefaction analysis in a probabilistic framework to incorporate aleatory uncertainties (cone penetration resistance, groundwater table, and amax) and epistemic uncertainties (liquefaction simplified model) via the Monte Carlo simulation. The developed probabilistic methodology is also applicable to a forward liquefaction assessment and other liquefaction sites globally. The median M from this probabilistic paleo-liquefaction for the four investigated sites lies between 8.8 and 9.0. Our probabilistic results also reveal that Cascadia interface earthquakes with M > 8.9 lead to a 31%–57% probability of liquefaction triggering in the Fraser River delta. In addition, we developed deterministic and probabilistic magnitude-bound curves specific to Cascadia interface earthquakes and representative site class E conditions. These curves provide more accurate magnitude estimations for predicting seismic-induced liquefaction from Cascadia interface earthquakes for sites in the Pacific Northwest than empirical bound curves.

Adaptive thermal comfort in naturally ventilated hostels of warm and humid climatic region, Tiruchirappalli, India

• Comfort range for hostel building was found between 26.1 and 32.8 °C. • The desired temperature was found to be 27.8 °C, while neutral temperature was 29.5 °C. • The comfort limit extended by 2.8 °C if air velocity rises from 0.1 to 1.1 m/s. • Sweating Acceptability extended the thermal acceptability limit from 31.8 to 32.4 °C. • At 26.6 °C temperature about 50% of the fans were found switched on. Thermal comfort is an important factor in hostel buildings when the aim is to maximize the productivity of the students. Due to the extreme weather conditions, achieving thermal comfort in a hostel building in a hot and humid climate is even more difficult. Studies conducted in naturally ventilated hostel buildings in warm-humid climates involved the influence of outdoor air temperature only up to 34.4 °C and have been conducted in a specific season. In contrast, the Tiruchirappalli climate is characterized by a higher range of environmental variables. Therefore, to understand the thermal comfort conditions and usage of the environmental controls in naturally ventilated hostel buildings at the higher range of the environmental variables, a thermal comfort field study spread over one year was carried out at the National Institute of Technology, Tiruchirappalli, India, in twenty-seven hostel buildings. This study relies on field observation and thermal comfort responses from 2028 questionnaires collected from the students between September 2019 to August 2020. The analysis revealed a neutral temperature of 29.5 °C and a comfort range from 26.1 °C to 32.8 °C, indicating a wide range of thermal adaptation than suggested by the National Building Code of India and ASHRAE standard 55. The preferred temperature was 27.8 °C, indicating that students preferred a cooler environment. Acceptability with sweating conditions extended the upper limit of thermal acceptability from 31.8 °C to 32.4 °C. The use of a mosquito net can increase the probability of opening a window. Results indicated that overall behavioral adjustment could extend the comfort limits. The study results would be helpful to develop guidelines and designs for naturally ventilated hostel buildings in warm and humid climates that will contribute to reducing energy demand.

An Investigation into Implementation of Project Quality Management Plan on Building Projects in Awka, Anambra State, Nigeria

The study is aimed at an investigating into the implementation of Project Quality Management Plan on Building Projects in Awka Anambra State, Nigeria, with a view to establishing the level of awareness and advocate the benefits associated with implementation of Quality Management Plan on building projects. This study adopted the use of structured questionnaires and literature reviews. The sample size was 250 building site managers, to elicit relevant data, and were analyzed by using simple percentage and Principal Component Analysis (PCA), using SPSS 23 software. The result indicate that construction practitioners are aware of PQMP in Awka, Anambra State and often apply the document to all building projects. The top benefits of implementing project quality management plan, are that it increases project efficiency and saves cost. At the end of the work, I recommend that Anambra State government should domesticate the national building code. Builders should be given the desired opportunity to manage the building production process in order to achieve efficient, cost saving, and quality projects in Anambra State.

Seismic performance evaluation of self-centering balloon-framed CLT building

Balloon-framed cross-laminated timber (CLT) construction has a number of advantages when compared to platform-type construction; however, many international standards only include provisions for the latter as there is little research reported on the seismic performance of the former. In this paper, a seismic fragility assessment of a 4-storey balloon-framed CLT building in Vancouver, Canada, is presented. This structure is the first in North America that adopts a self-centering friction-based technology for the hold-downs (HDs). The seismic performance of the building was assessed by performing incremental dynamic analysis (IDA) on a three-dimensional finite element model using Cascadia Subduction Zone ground motions, and compared to a second building model with conventional dowel-type HDs. The analyses at the design intensity level showed that the self-centering building had an average maximum inter-story drift ratio of 0.67%, well below the 2.5% drift limit specified in the National Building Code of Canada. Based on the IDA and taking into account uncertainties, the building had a collapse margin ratio of 2.96 and a 5.2% probability of collapse at the design level. Compared to the conventional HDs, the friction-based HDs did not improve the building’s collapse capacity, but reduced the building drift by more than 20% at lower damage states, demonstrating the effectiveness of designing balloon-framed CLT structures with a resilient self-centering HDs in high seismic zones.

Wind pressure on a 45° gabled roof: verifying code provisions with field measurements and wind tunnel data

The wind load provisions for gabled roofs with a slope of 27° < α < 45° in the National Building Code of Canada (NBCC) were derived from wind tunnel studies conducted in the 1970s. The coefficients have remained basically unchanged until this time. The paper presents the results of full-scale measurements and wind tunnel experiments to verify the necessity to update the current NBCC provisions. A full-scale building with a gabled roof of 45° was instrumented with pressure taps, and the wind load was monitored for 15 months. Special attention is given to the roof overhang by considering the simultaneous pressure contribution from both the upper and lower surfaces. The building and surroundings were replicated at a wind tunnel scale and investigated by Concordia University and Western University. Based on these three sources of data, the study concluded that the corner and edge provisions for both cases—a roof with and without overhang—need to be increased. It is suggested to merge the corner and edge into a single “perimeter” load provision. This code simplification would help the roofing industry to reduce misleading interpretations of the code and minimize failure due to installation errors.

Seismic microzonation mapping of Greater Vancouver based on various site classification metrics

The goal of the multi-year seismic microzonation mapping project for Greater Vancouver, British Columbia, Canada, is to produce seismic hazard maps inclusive of local site effects, in particular seismic hazard specific to one-dimensional site response and three-dimensional Georgia sedimentary basin amplification, as well as liquefaction and landslide hazard potential. We explore the variability in key seismic site characterization measures most often used for seismic microzonation mapping to evaluate the impact on mapping and communication of seismic microzonation of Greater Vancouver. This study focuses on the comparison of seismic microzonation maps of Greater Vancouver based on up to three seismic site term parameters and their associated classification schemes: 1) the time-averaged shear-wave velocity (Vs) of the upper 30 m (Vs30) and associated Canadian National Building Code (NBC) site class; 2) Vs30-based site classification proposed for the updated Eurocode 8; 3) site period (T0) determined from microtremor site amplification spectra; and 4) a hybrid site classification based on T0 and the average Vs and thickness of soil. 810 Vs30 and 2,200 T0 values are determined to evaluate sub-regional differences in these important seismic site parameters in Greater Vancouver. We find that the seismic microzonation of Greater Vancouver depends on the chosen seismic site parameter (Vs30, T0, or a combination of parameters) and that classification schemes with greater class divisions are beneficial to communicating the great variability in seismic site conditions in Greater Vancouver. We recommend that either one hybrid classification map or two classification maps of Vs30 and T0 together are required for effective communication of the seismic microzonation of Greater Vancouver.

Architectural Layout for a Three-Story Dormitory Integrating a Rainwater Harvesting Infrastructure

Residing within a college dormitory entails convenient strolls to classes, easy access to friends just down the corridor, and an immersion in the vibrant campus social milieu. The paper emphasizes the efficacy of the building's structural design in terms of robustness and durability, as well as how the building's aesthetics can hold a competitive edge on a global scale, all while adhering to the safety standards outlined in the building regulations of the Philippines. The design of the dormitory, complete with a rainwater harvesting system, encompasses various stages. These include the collection of data to establish the project's foundation, the creation of an architectural design to conceptualize the project, structural design and analysis to ascertain the building's strength and load-bearing capacity, electrical design to outline lighting and power plans, plumbing design to organize water distribution and determine suitable pipe sizes, a comprehensive work program detailing construction timelines and schedules, and cost estimates to gauge labor, equipment, and material expenses. The project's design, validated through tools like structural design software, adhered to the Philippines' National Building Code and National Structural Code, meeting all requirements without encountering failure or errors. The building's prerequisites underwent meticulous evaluation and verification. Consequently, it is implied that the project holds practical value and is both feasible and worthwhile.

Architectural Plan for A Bi-Level Annex Structure at Kasili Lakeside Resort and Hotel

The core focus of civil engineering lies in structural design, with the foundational principle in structural engineering being the creation of elemental components and sections for buildings. An annex building serves as an extension to the main edifice, fulfilling diverse user needs. This study's primary objectives encompass crafting an annex structure capable of rivalling the aesthetic appeal of prominent hotels, engineering resilience against climatic phenomena, addressing lakeside challenges, and assessing compliance with the National Building Code and National Structural Code of the Philippines. The study diligently fulfilled the aesthetic prerequisites set forth by the LGU of Mainit. Accounting for wind, earthquake, dead, and live loads directly impacting the structure, the researcher conducted a comprehensive analysis, leveraging resultant moments to design each structural element. Given the project's location atop an embankment, the researchers conservatively employed the weakest soil pressure to underpin footing design. Rigorous evaluation by industry professionals, aligned with the stipulations of the National Building Code of the Philippines, substantiated the structure's integrity, resulting in official approval.

Design of a Dome Utilizing Sustainable Energy Sources

In recent times, there has been a notable upsurge in the utilization of dome structures, recognized as highly efficient architectural forms. These structures offer optimal space coverage with minimal larger volumes, devoid of obstructive columns, resulting in enhanced efficiency and cost-effectiveness. Domes, particularly for circular spaces, provide lightweight roofing solutions. This study endeavors to present a design for a steel dome that adheres to the principles of the green building code. The Municipality of Sison, driven by the necessity for a versatile facility to accommodate a spectrum of events and activities, past and future, is the focal point of this proposal. The researcher intends to develop a dome design that aptly caters to these multifarious needs. Employing diverse theories within structural engineering, the structural analysis and design were manually computed, employing methods such as the slope deflection technique. The envisioned dome encompasses various facilities, including a basketball court and seating for up to 4,000 attendees. To meet energy requirements, solar power is harnessed, necessitating 138 units of 60-amp solar charge controllers to charge a 12 V 279,600 Wh battery, paired with a 69,900 W solar array. The dome's design underwent evaluation in collaboration with LGU-Sison and other key stakeholders. The estimated budget for the entire project approximates 102.6 million pesos. The structural design aligns with the guidelines stipulated by the National Building Code of the Philippines (NBCP) and the National Structural Code of the Philippines (NSCP). With earthquake-resistant attributes and adherence to energy efficiency standards specified by green building criteria, the design attains a comprehensive blend of safety and sustainability

Creating a Blueprint for a Tri-Level SSCT International Residence

The Surigao State College of Technology's International House at the Del Carmen Campus serves as an on-campus edifice catering to both local and foreign students' lodging needs. This establishment symbolizes an educational domain that transcends academic confines, fostering a milieu of shared experiences and diverse perspectives within the academic. At the core of this initiative lies the overarching objective of crafting an SSCT International House that not only assures a sense of contentment but also guarantees resident satisfaction. To actualize this vision, the research embarked on a comprehensive trajectory commencing with preliminary site inspection and meticulous data acquisition. With the endorsement of the campus director, the researchers executed a thorough assessment and conceptualization of every aspect of the entire structure. This endeavor aligns with the prevalent concrete framing system, a staple structural methodology. The structural design was subjected to rigorous evaluation in alignment with the National Building Code of the Philippines, National Structural Code of the Philippines, Fire Code of the Philippines, Sanitary/Plumbing of the Philippines, BP344, and the Green Building Code. The design was calibrated to factor in the effects of wind and seismic parameters, in addition to dead and live loads germane to the structure's integrity. The driving tenets of the Green Building Code further anchor the project, infusing an ethos of economic viability and environmental consciousness, sans substantial escalation in costs. The fruition of this project has culminated in meticulous documentation that satisfies the institutional requisites. Through stringent evaluation and validation processes, the structural soundness was verified by professionals, attesting to the alignment with code mandates, thereby garnering the coveted "approved" status. The designation of the SSCT International House as an on-campus entity underscores its significance as a secure haven for students, aligning with the educational institution's commitment to fostering a safe and conducive environment for its learners

About the Use of Concrete Damage Plasticity for Modeling Masonry Post-Elastic Behavior

Considering the high vulnerability of existing masonry buildings, which often have strategic or cultural value, professionals and specialized engineers are frequently required to model complex historical buildings. The approaches proposed by National Building Codes may not always be suitable for such cases, but more detailed approaches are necessary, relying on FEM continuum modeling and inelastic constitutive law. There are many constitutive laws proposed in the literature that allow us to accurately reproduce the mechanical behavior of masonry. However, they require the identification of several parameters that are not easy to determine. In this study, a sensitivity analysis of the parameters of a nonlinear constitutive law very popular for masonry modeling (the “Concrete Damage Plasticity—CDP” model) is conducted, considering literature tests of masonry panels under shear stress as the benchmark. The aim is to assess the influence of the main parameters of the model and compare them to one of the more commonly used Mohr–Coulomb failure criteria.

Seismic Resilience and Design Factors of Inline Seismic Friction Dampers (ISFDs)

While damping devices can provide supplemental damping to mitigate building vibration due to wind or earthquake effects, integrating them into the design is more complex. For example, the Canadian code does not provide building designs with inline friction dampers. The objective of this present article was to study the overstrength, ductility, and response modification factors of concrete frame buildings with inline friction dampers in the Canadian context. For that purpose, a set of four-, eight-, and fourteen-story ductile concrete frames with inline seismic friction dampers, designed based on the 2015 National Building Code of Canada (NBCC), was considered. The analyses included pushover analysis in determining seismic characteristics and dynamic response history analysis using twenty-five ground motion records to assess the seismic performance of the buildings equipped with inline seismic friction dampers. The methodology considered diagonal braces, including different 6 m and 8 m span lengths. The discussion covers the prescribed design values for overstrength, ductility, and response modification factors, as well as the performance assessment of the buildings. The results revealed that increasing the height of the structure and reducing the span length increases the response modification factors.

Planning and Design of Residential Building

Abstract: This project analyzes and design a residential building.The structure has been designed Using pile foundation. The proposed residential building is to be constructed at Mendhasal, Bhubaneswar. The area of the proposed building 1500 sq ft (G+2) will be constructed framed structure. The analysis of frames to compute the force and moment will be carried out with staad pro software. AutoCAD software will be used for planning of the building. Staad pro software will be used for analysis of building as well as IS 456:2000 code of practice for plain and reinforced cement concrete. The structural members are like slabs, beams; columns are designed with limit state method using national building code and IS 456:2000 grade concrete and grade of steel are to be used. The project is to develop independent and creative thinking fundamental theoretical knowledge we obtained during the course of the study practical application of field.

Design Demands of RC Buildings Due to Irregularities

The RC-framed building is one of the most common construction technique for seismic-resistant structures due to its ductile nature. However, the seismic performance of RC structures can be significantly influenced by different factors, irregularities being one of the most important aspect. Irregularities on buildings increase the lateral seismic forces and inter-storey drifts thus increasing seismic demands in the structural elements. Due to architectural or functional requirements, many times irregularities cannot be avoided even though such arrangements are discouraged in the building codes including the Nepal National Building Code (NBC) 105:2020. Although many studies have been performed to quantify the effects of such irregularities internationally, design effect has not been analyzed in the context of Nepal and NBC 105:2020. Therefore, this study aims to present the variation in design demand for RC buildings in different irregularities scenarios. Three buildings models exhibiting irregularities in torsion, stiffness, and diaphragm are taken and analyzed in Finite Element platform SAP 2000 and compared with a regular building in terms of storey drift, internal forces, etc. The final design of the structural elements shows that the design demand in terms of section size and reinforcements can be significantly influenced by the presence of such irregularities.

A new shear test setup for determining shear strength of normal and high strength concrete

Since the start of the 20th century various investigators proposed different shapes, sizes of specimens to determine the shear strength of concrete and proposed several models. Several disagreements and discussions were surrounding the concept of shear strength, particularly in case of High strength concrete (HSC). In order to compare the shear strengths of Normal Strength Concrete (NSC) with High Strength Concrete, a “New shear test setup” was proposed in this study. From literature and different standard codes, it was found that, the shear strength of plain concrete becomes constant after certain compressive strength. Different authors and codes proposed different strength of concrete beyond which the shear strength becomes constant. The aim of the study was to find the compressive strength beyond which the shear strength becomes constant using the proposed shear test setup. In order to obtain the shear strength, 42 cubes of 150 mm × 150 mm × 150 mm of concrete of varying strength of 20 MPa to 80 MPa were cast and tested. The experimental results were compared with a numerical model based on FEM software ATENA and the existing models proposed in the literature. It was found from the experimental work that the shear strength became constant after a compressive strength of 50 MPa- 60 MPa. According to the shear strength results, there was a significant correlation between experimental results and results predicted using ATENA software. Moreover, the experimental results were compared with the shear strength values predicted by various national building codes and various shear models proposed using the different shear test setups. It was found that the experimental results closely match with the values obtained by AS: 3600–2018 equation and Mattock equation's based on the push-off specimen.

Different orientations of shear wall in a reinforced concrete structure to control drift and deflection

While Dhaka, the capital city of Bangladesh, adapts to more and more high-rise buildings and skyscrapers, concerns remain about their design efficiency and ability to withstand shear loads from seismic movements. In this study, several orientations and placements of shear walls in a regular G +15 story reinforced concrete building were assessed to observe the nature of the structure subjected to earthquake seismic loads by adopting the Equivalent Static Analysis. CSi ETABS 2019 was utilized to analyze the story shear, drift, displacement, stiffness, torsional irregularity and compared against eight separate models with different shear wall placements. The significance of this study lies in its contribution to the area of designing earthquake-resistant structures with appropriate shear wall locations following the recent Bangladesh National Building Code 2020 (Seismic criteria as per ASCE 7-05). Results reveal that shear walls placed symmetrically and along the shorter span for the selected structural plan have shown less lateral drift and displacement than structures with other shear wall orientations.

Vertical floor spectra in low- and mid-rise elastic RC moment resisting frame buildings

To examine how floor spectral accelerations affect the design force of flexible Non-Structural Components (NSCs), the present study discusses the estimation of floor response spectra resulting from strong vertical seismic motion. 3-, 6-, 9- and 12-storey reinforced concrete buildings with moderately ductile moment-resisting frame systems, designed in accordance with the National Building Code of Canada [25] were selected for this research. 65 sets of historical records relating to 31 severe earthquakes from across the world were used to analyze the linear behavior of these structures. A constant amplification of the Vertical Floor Spectral Acceleration (FSAV) was observed along the building height. This amplification was noticeably elevated for slab nodes, especially at the center of the interior slab and in shorter buildings. Furthermore, the vertical component of the earthquake had a greater impact at shorter periods, since the maximum vertical acceleration occurred at periods lasting less than 0.35 sec. Finally, equations to estimate FSAV corresponding to the input vertical ground acceleration were proposed for typical code-conforming RC frame buildings.

A national seismic risk model for Canada: Methodology and scientific basis

Canada is exposed to rare but potentially destructive earthquakes that threaten densely settled metropolitan centers in many parts of the country. To assess the impacts and consequences of future natural-hazard events and help advance policy goals and objectives of the Sendai Framework for Disaster Risk Reduction, Natural Resources Canada, through a collaborative partnership with the Global Earthquake Model Foundation, produced a national seismic risk model. Developing this model has required the creation of a national exposure inventory, Canadian-specific fragility and vulnerability curves, and significant simplification of the Canadian Seismic Hazard Model which forms the basis for the design seismic hazard values of the National Building Code of Canada. Using the Global Earthquake Model Foundation’s OpenQuake Engine, probabilistic stochastic risk modeling is completed under baseline and simulated retrofit conditions to assess seismic risk at the neighborhood level for all settled areas in Canada. Output risk metrics include the expected immediate physical impacts of earthquake events such as building damage, casualties, and direct economic losses. This article documents the technical details of the modeling approach including a description of novel data sets in use, a summary of the extensive sensitivity testing undertaken, and characterization of quality control implemented in the absence of usable validating earthquake loss data. The results from this model, such as loss exceedance curves and annual average losses, provide an open, accessible and quantitative base of evidence for decision-making at local, regional, and national levels. As a large country with a complex seismic hazard model and dispersed populations, this Canadian study is unique. However, the challenges faced and solutions offered are likely to be of interest to other nations pursuing similar programs.

A Community Building Energy Modelling – Life Cycle Cost Analysis framework to design and operate net zero energy communities

Despite building codes and standards helping build energy-efficient structures, most focus only on typical individual buildings. Second, they do not discuss community-based renewable energy adoption strategies as part of the standards. However, to facilitate the transition to net zero emissions in the upcoming decades, policies and recommendations from standards must enhance their scope from the buildings to communities and exploit the maximum energy retrofit opportunities available within the community premises. This study proposes a Community Building Energy Modelling – Life Cycle Cost Analysis (CBEM - LCCA) decision-making framework to analyze the techno-economical feasibility of the residential community-wide implementation of any building retrofit scheme. The framework developed is applied in a 14-building residential community in Mumbai, India, to compare the techno-economic benefit of implementing community-wide renewable installations against the existing national Energy Conservation Building Code (ECBC). The results reveal that all the communities together have the potential to generate 333 MWh of electricity per year from solar rooftops alone against the consumption of 369 MWh. The communities are observed to be capable of achieving nearly net-zero energy after adopting a community-wide rooftop solar photovoltaic installation with fewer than eight years of simple payback period (SPP). A thorough sensitivity analysis also reveals that the community rooftop solar strategy proves economically far superior to ECBC compliance of individual building envelopes. Among the retrofits, the roof-wall combination gave the minimum SPP of 8.38 years at a 100 % cooling space fraction. The findings provide evidence for why only a small number of states support ECBC code compliance, and it is recommended that policymakers use the proposed CBEM-LCCA framework to create appropriate energy policies for developing community-wide rather than individual building-level retrofit strategies.