Nonstructural Building Components Research Articles

Recommendations for Ω0 for Anchorage into Concrete for Floor-Mounted Nonstructural Components

AbstractRelative to ductile anchors, nonductile anchors have long been subject to increased design safety margins in U.S. building codes for nonstructural building components. Historically, a safet...

In-situ seismic verification of non-structural components of unreinforced masonry buildings

An experimental campaign was developed to evaluate the response of non-structural elements of unreinforced masonry buildings for simulated earthquake loads. Eleven walls within 4 URM properties were subjected, in situ, to uniformly distribute static loads applied using a system of airbags. The buildings were located in Darlington, a suburb of Adelaide, South Australia. Three of them were built in the 1960s and the fourth was built in the 1980s. Accompanying material tests were done in situ and in the laboratory, enabling a comparison to be made between the old buildings material strength and the default material strengths recommended in the Australian Masonry Standards, AS3700. Tests were also conducted on 3 URM chimneys to establish their failure mechanism and strength. A highlight of this research is the findings that existing masonry chimneys are vulnerable to a ‘design earthquake’ in Australia. The results also suggest that despite masonry material strength being significantly lower than the code default values, the walls satisfied expected seismic force demands. The reasons include the beneficial effects of in situ wall boundary conditions on out-of-plane wall strength.

Performance of early masonry, cob and concrete buildings in the 14 November 2016 Kaikoura earthquake

The performance of historic buildings during the 14 November 2016 Mw7.8 Kaikoura, New Zealand earthquake is reported, focusing on early stone and clay brick masonry buildings, vintage concrete structures, cob cottages, and the non-structural masonry chimneys and veneers of buildings located in the upper part of the South Island (Marlborough and North Canterbury regions). To better document structural response, the intensity of horizontal and vertical ground motion from the nearest recording station is graphically placed alongside the assessed level of damage. In response to numerous strong earthquakes that have previously occurred in the area a large number of highly vulnerable buildings or non-structural building components were previously either seismically retrofitted or demolished, thereby reducing the level of damage and loss of life during the 2016 Kaikoura earthquake. Seismically retrofitted stone and clay brick masonry buildings and cob cottages exhibited good performance, while some vintage concrete structures and partially strengthened cob cottages suffered moderate to extensive levels of damage. A large stock of URM chimneys in Picton, Seddon and Rotherham were previously removed while in other locations chimneys presented a variety of responses. Rural masonry veneer dwellings located in Seddon and Waiau experienced high damage levels, typically resulting in out-of-plane collapse of the masonry veneer.

Gap between Code Requirements and Current State of Research on Safety Performance of Fiber-Reinforced Polymer for Nonstructural Building Components

Gap between Code Requirements and Current State of Research on Safety Performance of Fiber-Reinforced Polymer for Nonstructural Building Components

Reliability-Based Evaluation Of Loss Due To Distribution Of Nonstructural Components In Height

Abstract Structural and nonstructural components incorporate simultaneously and correspondingly in modern probabilistic performance evaluation to make decision making parameters which is usually economic loss in a predefined level of probability. However, far greater investment, relatively limited seismically design information and dependence of nonstructural components’ normative quantities to some architectural, economic and social features contribute to exceeded loss amounts and uncertainties under nonstructural components in comparison to structural ones. This paper addresses the question of how to distribute nonstructural components in height of a building accounting for more reliable economic loss subjected to seismic excitation through application of fully probabilistic reliability approach. This purpose has been captured through proposing a new modified distribution of building nonstructural components in height for three typical steel moment frames and conducting comparative assessments for two alternative distributions of nonstructural components with office occupancy. Dealing with discussions, it could be concluded that more reliable economic losses could be gained and also reduced by more astutely situating building nonstructural components in height considering type of dominated demands in a specific story without requirement to any alternation in component’s type or quantity.

Distribution of Building Nonstructural Components in Height Subjected to Cost of Damage for Low-Rise Office Buildings

Exceeded losses of nonstructural components from structural ones in most demolished buildings in previous earthquakes and its limitation on functionality of critical facilities and building serviceability after earthquakes should be got the point of view for accounting loss of building as a merit for building performance. This paper attempts to demonstrate the significant role of distribution pattern of building nonstructural components in height accounting for economic losses due to seismic excitation. To achieve this purpose a new modified distribution of nonstructural components in height is proposed for three typical steel moment frame models by office occupancy and comparative assessments between two competing distribution of nonstructural components are conducted. Dealing with discussions, it could be concluded that the economic losses could be reduced by more astutely situating building nonstructural components in height considering type of dominated demands in a specific story without requirement to any alternation in component's type or quantity.

Textile Effluent Treatment Plant Sludge: Characterization and Utilization in Building Materials

The main objective of this study is to characterize and find a potential use of textile effluent treatment plant (ETP) sludge produced in Bangladesh. Textile ETP sludge collected from the local textile industries have been characterized in the laboratory. The physicochemical and engineering properties of the sludge have been studied. Collected ETP sludge has been processed to get cement-like fine powder that has been used for partial replacement of Portland cement/sand in the composition of the mortar and concrete specimens. Different mechanical (compressive and flexural strength), physical (water absorption) and morphological (porosity) properties of the test specimens have been evaluated. The test result shows that the addition of sludge in the mortar and concrete composition as a substitution of Portland cement or sand decreases the compressive strength and flexural strength, and increases the water absorption and porosity of the mortar and concrete specimens. Leaching study, conducted for the sludge-based mortar and concrete specimens following tank leaching test procedure, reveals that the concentration of leached metals is quite low than the limits specified by the Department of Environment in Bangladesh. These results amply demonstrate that textile ETP sludge can be utilized for making non-structural building components where lower strength is justified.

An Overview of the Current Code Provisions on the Seismic Response of Acceleration-Sensitive Non-Structural Components in Buildings

The seismic response of non-structural components in civil and industrial buildings, often neglected or disregarded in the common design/assessment practice, revealed its dramatic relevance in recent seismic events that resulted in significant damage observed in the wide class of “objects” referred to as “non-structural components” (e.g., partitions, masonry infill, suspended ceilings, finishing, specific equipment and so on. The observed damage, sometimes leading to collapse of these components and even loss of human lives, highlighted the lack of knowledge that still affects both analysis procedures and design/assessment methods currently adopted for analysing their seismic response. This paper is mainly intended at providing readers with an overview of both the historical development and the current state of the formulations adopted by codes and standards for evaluating the maximum accelerations induced by seismic shakings on non-structural components. The difference among these formulations is firstly outlined and the predictions based on the most up-to-date codes are compared with the results of a wide parametric analysis based on a 2DOF system, intended at simulating the coupled response of both main structure and non-structural component. This parametric comparison shows that the current formulations are not fully capable of reproducing the effect of the interaction between main structure and non-structural components

Landmark Data Set from the Building Nonstructural Components and Systems (BNCS) Project

A full-scale, five-story reinforced concrete building fully equipped with non-structural components and systems (NCSs) was tested to a near collapse condition on the large outdoor shake table at the University of California, San Diego in 2012. This landmark test program was intended to advance the understanding of the seismic behavior of NCSs installed in buildings, and for this reason it was named the Building Nonstructural Components and Systems (BNCS) project. The BNCS test specimen was monitored with digital still cameras, more than 80 video cameras, 500 analog sensors, and a global positioning system (GPS) and subjected to a suite of earthquake input motions of increasing intensity while in a base-isolated and fixed-base configuration. The resulting high-quality data set is now publicly available within the NEES repository (NEEShub; DOI: 10.4231/D38W38349). The goal of this paper is to outline the types of data available and provide a road map for navigating through it in an effort to support its future use by the community.

Simulation of earthquake-induced hazards of falling exterior non-structural components and its application to emergency shelter design

In addition to earthquake-induced structural collapse, hazards related to falling exterior non-structural components of buildings have also been recognized as a significant safety problem. A novel simulation method is proposed herein to reduce such type of hazard, which has rarely been studied in the existing literature. Using a multi-story concentrated-mass shear model and specific falling criteria for exterior non-structural components, the hazard ranges of falling objects in a building group are simulated. The uncertainty of ground motion is considered via the incremental dynamic analyses. Thus, the distribution probabilities of falling objects during the design life of a building group can be predicted. A residential community area is considered as a case study for calculating the distribution probabilities of falling objects over a design period of 50 years and for selecting a suitable and safe site for an emergency shelter. This study is expected to provide a useful reference for emergency and disaster management.

Comparative response and performance of base‐isolated and fixed‐base structures

SummaryA building with a seismic isolation system, in an earthquake, is recognized as producing substantially smaller accelerations and deformations compared with a building that use other systems. This type of system is therefore expected to better protect the building's nonstructural components, equipment, and other contents that are essential for the activities conducted in the building. Unlike many available studies on building responses, only a small number of studies on a buildings' nonstructural component responses are available, and no study has directly addressed building performance with regard to nonstructural component protection. This paper therefore measures the performance of various seismically isolated buildings. Specifically, the effects of important structural parameters, namely, isolation stiffness, isolation damping ratio, and number of stories on the response of base‐isolated structures are investigated parametrically. Ground motions with 2% exceedence in 50years Maximum Considered Earthquake (MCE) are used. Performance is compared with that of fixed‐base structures in order to present data that will be useful in justifying the more costly technology. The buildings are 3, 9, and 20 stories, represented by MDOF shear‐beam models. As examples of displacement‐sensitive and acceleration‐sensitive components, partition walls and ceilings are considered, respectively. The Pacific Earthquake Engineering Research Center performance‐based earthquake engineering methodology is adopted to evaluate the failure return periods of the examples based on their available fragility curves. In addition, the curves are varied hypothetically to understand the sensitivity of the return period to the curve features. Then, the median and dispersion of fragility curves required to satisfy the components' desired failure return period are obtained. Copyright © 2015 John Wiley & Sons, Ltd.

Seismic nonstructural vulnerability assessment in school buildings

This paper addresses the large-scale classification of the seismic vulnerability of nonstructural components in school buildings. A rapid visual screening methodology is proposed that highlights the factors that likely have a major effect on the seismic behavior of nonstructural building components. This methodology is based primarily on questionnaire forms that are used to construct a nonstructural index and priority ranking that identifies the most vulnerable category of nonstructural components. Because numerical answers in the questionnaires can produce unreliable results, a calibration of the categories by weight is proposed via fragility functions to obtain a vulnerability index. Finally, the developed methodology is applied to a case study of school buildings in Italy.

Developing fragility curves and loss functions for masonry infill walls

The primary objective of this study is to summarize results from previous experimental tests on laboratory specimens of RC/steel frames with masonry infills, in order to develop fragility functions that permit the estimation of damage in typical non-structural components of RC frame buildings, as a function of attained peak interstory drift. The secondary objective is to derive loss functions for such non-structural components, which provide information on the probability of experiencing a certain level of monetary loss when a given damage state is attained. Fragility curves and loss function developed in this study can be directly used within the FEMA P-58 framework for the seismic performance assessment of RC frame buildings with masonry infills.

Utilization of Brine Sludge in Nonstructural Building Components: A Sustainable Approach

The characterization and influence of brine sludge on the properties of cement-fly ash-sludge binders are presented. The reaction products formed during the hydration of binder provide an interlocking framework to physically encapsulate the waste particles and are responsible for the development of strength. The utilization of brine sludge in making paver blocks and bricks and the effect of sludge concentration on the engineering properties of these products are also discussed. These results clearly exhibited that brine sludge up to 35 and 25% can safely be utilized for making paver blocks and bricks, respectively. The leachability studies confirm that the metals ions and impurities in the sludge are substantially fixed in the matrix and do not readily leach from there. The utilization of brine sludge in construction materials could serve as an alternative solution to disposal and reduce pollution.

Performance-based seismic design of nonstructural building components: The next frontier of earthquake engineering

With the development and implementation of performance-based earthquake engineering, harmonization of performance levels between structural and nonstructural components becomes vital. Even if the structural components of a building achieve a continuous or immediate occupancy performance level after a seismic event, failure of architectural, mechanical or electrical components can lower the performance level of the entire building system. This reduction in performance caused by the vulnerability of nonstructural components has been observed during recent earthquakes worldwide. Moreover, nonstructural damage has limited the functionality of critical facilities, such as hospitals, following major seismic events. The investment in nonstructural components and building contents is far greater than that of structural components and framing. Therefore, it is not surprising that in many past earthquakes, losses from damage to nonstructural components have exceeded losses from structural damage. Furthermore, the failure of nonstructural components can become a safety hazard or can hamper the safe movement of occupants evacuating buildings, or of rescue workers entering buildings. In comparison to structural components and systems, there is relatively limited information on the seismic design of nonstructural components. Basic research work in this area has been sparse, and the available codes and guidelines are usually, for the most part, based on past experiences, engineering judgment and intuition, rather than on objective experimental and analytical results. Often, design engineers are forced to start almost from square one after each earthquake event: to observe what went wrong and to try to prevent repetitions. This is a consequence of the empirical nature of current seismic regulations and guidelines for nonstructural components. This review paper summarizes current knowledge on the seismic design and analysis of nonstructural building components, identifying major knowledge gaps that will need to be filled by future research. Furthermore, considering recent trends in earthquake engineering, the paper explores how performance-based seismic design might be conceived for nonstructural components, drawing on recent developments made in the field of seismic design and hinting at the specific considerations required for nonstructural components.

Floor Accelerations in Yielding Special Moment Resisting Frame Structures

Severe damage to acceleration sensitive nonstructural components in recent earthquakes has resulted in unprecedented losses. Recent research has been aimed at increasing the understanding of acceleration demands on nonstructural components in buildings. This investigation subjects a set of four special moment resisting frame (SMRF) building models to a suite of 21 far-field ground motions using the incremental dynamic analysis procedure. Full three-dimensional models including floor slabs are used to extract both the horizontal and vertical responses. Floor acceleration response spectra are generated to assess the acceleration demands on elastic nonstructural components. Changes to the current code provisions that include the influence of structural period are proposed. An alternative design approach that directly amplifies the ground acceleration spectrum to achieve the desired floor acceleration spectrum is presented.

Evaluation of current seismic design equations for nonstructural components in tall buildings using strong motion records

SUMMARYA recently completed California Strong Motion Instrumentation Program (CSMIP) data interpretation project used recorded ground and floor motion data to evaluate a key ASCE/SEI 7‐05 (and 7‐10) equation for seismic design of acceleration‐sensitive building nonstructural components. CSMIP motions from 73 earthquakes recorded in 151 fixed‐base buildings were used in the evaluation. An improved equation was developed with two categories of revisions. First, the current code formula considers a linear relationship between the peak floor acceleration (PFA) and the relative height of the component in the building with a roof PFA that is three times that of the peak ground acceleration. The analyses of the recorded motions showed that improved results could be obtained by using a nonlinear relationship and by considering both the building approximate period, Ta, and the level of ground motion. Second, the code formula considers a component amplification factor, ap, that takes values between 1.0 and 2.5 depending on the flexibility of the nonstructural component. Analyses showed that component amplification factor can be better represented using a three‐segment spectrum composed of a linear rise from 1.0 to maximum value of ap at short periods, a flat segment with the maximum value of ap at medium‐range periods and a nonlinear decaying segment at longer periods. The shape and amplitude of the spectrum were found to vary depending on Ta. This paper evaluates tall buildings with at least 15 stories using the proposed equations and confirms that the revisions provide improvements in matching design equations with recorded response. Copyright © 2011 John Wiley & Sons, Ltd.

Study of Loading Protocols in Light-Gauge Stud Partition Walls

This paper examines the influence of two reversed cyclic loading protocols on the response of gypsum light-gauge metal-stud partition walls, which are common in office, hotel, and laboratory buildings. Two identical full-scale three-dimensional specimens were constructed to represent a typical room in an office building. The specimens were tested quasi-statically along two axes using different loading protocols. The loading protocols were applied to observe the sensitivity of loading protocol on damage progression. The loading protocols were developed for the Applied Technology Council ATC-58 project published in FEMA 461, which, among others, addresses the racking protocol of nonstructural building components for use within a performance-based earthquake engineering framework. Details are given about the damage progression of the specimens to the loading protocols and their lateral force-displacement response characteristics.

DAMAGE TO NON-STRUCTURAL COMPONENTS IN LARGE ROOF BUILDINGS FAILED DURING THE IWATE-MIYAGI NAIRIKU EARTHQUAKE IN 2008 OR AN EARTHQUAKE IN THE NORTH SHORE OF IWATE PREFECTURE IN JULY 24TH OF 2008

Damage to non-structural components in large roof buildings, failed during the Iwate-Miyagi Nairiku Earthquake in 2008 or an earthquake in the north shore of Iwate prefecture in July 24th of 2008, is reported.The northeastern region of Japan had been hit by major earthquakes frequently in recent years. Nevertheless, the similar damage had been repeated, since the failed parts had been fixed and recovered always with no essential improvements.

2008年岩手・宮城内陸地震, 岩手県沿岸北部地震における大規模集客施設の非構造材被害について

2008年岩手・宮城内陸地震, 岩手県沿岸北部地震における大規模集客施設の非構造材被害について