Floor Of Building Research Articles

Numerical studies on the seismic response of a three-storey low-damage steel framed structure incorporating seismic friction connections

A 9 m high, near full scale three-storey configurable steel frame composite floor building incorporating friction-based connections is to be tested using two linked bi-directional shake tables at the International joint research Laboratory of Earthquake Engineering (ILEE) facilities, Shanghai, China, as part of the RObust BUilding SysTem (ROBUST) project. A total of nine structural configurations are designed and detailed. To have a better understanding of the expected system behaviour, as well as effects of other structural and non-structural elements (NSEs) on the overall system response, experimental testing at component level has been conducted prior to the shake table testing. This paper presents an introduction to the ROBUST project, followed by a numerical study on one of the nine configurations of the structure, having Moment Resisting Steel Frame (MRSF) in the longitudinal direction and Concentrically Braced Frame (CBF) in the transverse direction. Hysteretic properties employed in the numerical models are validated against component test results. The predictions of the building's seismic response under selected base excitations are presented indicating the likely low damage performance of the structure.

A novel formulation for transfer path identification and vibration prediction in the over-track building induced by trains.

Over-track buildings in metro depots become more and more prevalent in metropolis with the increase in population and the decrease of construction land. However, the train-induced vibration greatly reduces the comfort of occupants living in the over-track buildings. Owing to complex vibration sources and numerous transfer paths, it is a challenging task to analyze and predict the vibration characteristics accurately in the building. In this paper, a field measurement campaign of vibration was conducted in the Guanhu metro depot in Guangzhou, China. A novel formulation based on the operational transfer path analysis (OTPA) and singular value decomposition (SVD) is proposed to analyze the measured data and predict the train-induced vibration in the building. In this study, the vibration contributions from each transfer path to the target points in the building were obtained and the predominant transfer paths were identified further. Besides, the vibration at target points in the building was predicted using the vibration at path points and transmissibility functions from transfer paths. This study provides insights into the prediction and evaluation of vibration transmissions from vibration source to upper floors of over-track building.

A machine learning regression approach for pre-renovation construction waste auditing

The activity from which construction waste arises includes new construction, renovation, and demolition. Renovation waste was traditionally considered as trivial but in recent years, it has gradually come into the focus of construction waste management (CWM). Waste auditing prior to renovation (termed ‘pre-renovation auditing’ or PRA) provides a departure point for good CWM. The core of PRA is accurately predicting renovation waste generation. Benefiting from a valuable dataset containing 351 building renovation projects in Hong Kong, this research aims to develop a robust renovation waste estimation approach. By using machine learning regression, a model containing several easy-to-access features was developed. By simply inputting the feature data (including renovation work type and cost; building type, year, height, and floor area; as well as floor height and the number of renovated floors) into the model, the renovation waste generated from the project can be reliably estimated. Validation experiments indicate that the method has a root mean squared error (RMSE) of 141.52, mean absolute error (MAE) of 79.69, and R-square of 0.83. Comparative experiments show that our method performs better than prevailing ones as reported in the literature. This study thus contributes a novel waste prediction model for pre-renovation waste auditing. With proper modifications, the model can be applied to other regions with different building and renovation features. Future research is recommended to further explore advanced waste estimation methods by integrating new technologies for finer CWM.

Optimal Ensemble Scheme for Human Activity Recognition and Floor Detection Based on AutoML and Weighted Soft Voting Using Smartphone Sensors

In this article, human activity recognition (HAR) attempts to recognize the activities of an object in a multistory building from data retrieved via smartphone-based sensors (SBSs). Most publications based on machine learning (ML) report the development of a suitable architecture to improve classification accuracy by increasing the parameters of the architecture pertaining to HAR. Due to robust and automated ML, it is quite possible to develop a versatile approach to improve the accuracy of HAR. This research proposes an optimal ensemble HAR and floor detection (OEC-HAFD) scheme based on automated learning (AutoML) and weighted soft voting (WSF) using SBS to improve the recognition rate. The proposed HAR-FD scheme is developed based on twofold mechanisms. First, an AutoML paradigm is employed to find optimal supervised models based on performance. Second, top-ranked (optimal) models are combined using the WSF mechanism to classify HAR on various floors of a multistory building. The proposed scheme is developed based on real-time SBS: accelerometer and barometer data. The accelerometer data are used to detect activity by observing the magnitude of the sensor measurements. Similarly, the barometer sensor detects floor height by using pressure and altitude data. Furthermore, we analyze the performance of the proposed optimal ensemble classifier (OEC) and compare them with the state-of-the-art classifiers. Based on the result analysis, it is clearly seen that the proposed OEC outperforms the performance of the individual classifiers. Moreover, our proposed HAR-FD can be leveraged as a robust solution to accurately recognize human activities in multistory buildings compared to the existing standalone models.

Full-Scale Floor System Testing for Future Hot-Rolled Asymmetric Steel I-Beams

The presented study conveys the initial full-scale experimental study for future hot-rolled asymmetric steel I-beams, termed A-shapes. The primary use for these beams is residential building floor systems. Current systems commonly utilize concrete solutions, which achieve a shallow depth for optimal floor-to-floor heights. However, these floor systems are relatively slow to construct because of the amount of formwork, rebar and post-tensioning placement, and shoring needed. The shallow-depth steel-concrete floor system concept explored in this research aims to improve the speed and efficiency of residential building construction. This increase in speed is achieved through hot-rolled steel A-shapes, which reduce the fabrication time for beam production. These steel shapes have a wide bottom flange that can support precast concrete panels or deep metal decking. Therefore, a relatively easy to assemble shallow-depth system can be achieved. The research study presented herein includes the experimental feasibility testing of a full-scale shallow-depth steel-concrete floor system to further the knowledge of A-shape performance in such systems. The floor system concept evaluated consisted of three steel A-shapes, precast hollow-core concrete panels, and a cast-in-place concrete topping slab. The testing involved taking measurements during construction, service live loading, and loading of the system to failure. The major unknowns were constructability, stability during construction, live load performance, and composite behavior. This experiment revealed that the system was constructed easily and rapidly and also remained stable during construction. The system performed well under service live load, experiencing deflections equivalent to L/3,000. The system failed due to the bond breaking between the concrete and steel, going noncomposite after experiencing partially composite behavior. This occurred at an actuator load equivalent to five times the design service live load. All of this indicates that the floor system concept using A-shapes is a legitimate path forward to faster construction of residential facilities. This validates the need for the research toward standardized A-shapes in the United States.

A Study on Communication and Conflict Management Using Social Networks: Analyzing Business Relations between Departments in Cheongju City

Good communication between members contributes to coordinating and resolving conflicts within the organization (Lee et. al., 2012). There was a special office space on the 3rd floor of the main building of Cheongju City Hall. That was BICHAENAUM, named after “Empty, fill, and share, and newness springs up”. In BICHAENAUM, about 50 officers from three departments worked freely in an open space. In this study, in preparation for the expansion of spatial innovation in the Cheongju City Hall, was to analyze the work relevance by the department and refer to the arrangement of departments with high relevance in the same space. The working relationship between departments was examined through social network analysis. As a result, departments in Cheongju City Hall were classified into 9 groups. In the long term, we hope that this study will serve as a basis for achieving the goal of improving working methods for spatial innovation.

West Sumatra Basketball Coaches Capacity Improvement In Making Physical and Mental Training Programs for Athletes

At present, the achievements of basketball in West Sumatra have not shown a significant increase. PERBASI West Sumatra has made various efforts through programs that have been made for basketball achievements in West Sumatra. To overcome this problem, it is necessary to add a program that also pays attention to the coach's side, where the coach is the person who is considered to have the most important role in improving the athlete's ability. This community service activity involved basketball coaches in West Sumatra in general and Pariaman City in particular. This trainer capacity building activity begins on 20-21 August 2022, at 09.00-12.00 WIB and takes place on the second floor of the LKAAM Building, Pariaman City, Pauh Barat Village, Central Pariaman District. Submission The physical exercise material presented recommends following the principles of Frequency, Intensity, Time, and Type. As for mental training, it is recommended to apply methods such as imagery and visualization as well as relaxation. The activity was attended by 25 participants. On the first day, the material for physical training was discussed, while the second day for mental training was the subject of discussion. Based on the results of the evaluation, it can be concluded that the participation of the basketball coaches and sports teachers who took part in this activity was quite good and the coaches and sports teachers also looked enthusiastic and enthusiastic.

A prototype low-carbon segmented concrete shell building floor system

Concrete shell structures offer a mechanically efficient solution as a building floor system to reduce the environmental impact of our buildings. Although the curved geometry of shells can be an obstacle to their fabrication and implementation, digital fabrication and affordable robotics provide a means for the automation of their construction in a sustainable manner at an industrial scale. The applicability of such structures is demonstrated in this paper with the realisation of a large-scale concrete shell floor system, completed by columns, tie rods, and a levelled floor. The shell was prefabricated off-site in segments that can be transported and assembled on-site, and which can be disassembled to enable a circular economy of construction. This paper presents the conceptual and structural design; the automation of fabrication, thanks to an actuated, reconfigurable, reusable mould and a robotic concrete spraying process; the strategy and sequence of assembly and disassembly on-site using standard scaffold elements; and the sustainability assessment using life-cycle analysis. This prototype offers a reduction of about 50% of cradle-to-gate embodied carbon benchmarked against regular flat slabs before further improvement and optimisation.

The Gap in Insurance Liability for Blood and Research Gamma Irradiators.

In 2019, a federal contractor accidently breached a 2,900 Ci 137 Cs sealed source while decommissioning it from a University of Washington research building, releasing a single digit curie of its contents. This event contaminated 13 people as well as all seven floors of the research building, which housed the radiation source. Estimates for clean-up costs and lost revenue exceeded $150 million. The magnitude of this cost prompted licensees in possession of such radioactive sources to question whether their insurance coverage is adequate to cover a large-scale incident and if coverage for such exposure even exists. In this article, we identify potential gaps in commercially available insurance policies by evaluating and assessing associated risks, damages, and accountability. While insurance can mitigate the expense associated with remediation, it is unlikely that sufficient limits would exist to fully protect healthcare institutions from direct financial liability in the event that their radioactive sources are implicated in a nuclear, chemical, biological, or radiological (NCBR) (sometimes called CBRN in other literature) mass contamination event. This paper seeks to outline how the risks and liability to healthcare institutions having such gamma irradiators can be reduced significantly by removing them rather than seeking to insure against the cost of remediation in the event of a leak and/or mass contamination. As such, licensees are encouraged to check their policies for the correct coverage and make sure any coverage restriction is removed from their policies. In addition, licensees are also encouraged to explore financial incentives offered by the US government programs to not only dispose of their present gamma irradiator sources at no cost but also to provide financial support to replace them with alternative technologies.

A Fast Method for Identifying Room Configurations from Unit Boundaries in Existing Residential Buildings

Prediction of interior room layout from observations on the exterior boundaries of a unit is sometimes needed in cases of emergencies when unit entry is denied. Seeing that 3D laser scanners are becoming smaller, lighter, and easier to carry around, this paper attempts to offer a fast method that can automatically reconstruct a room model relying merely on the 3D point cloud of the unit boundaries. The method first partitions the building floor space to generate the so-called “room seeds” from the intersections of lines that are extended from the detected wall segments. Then, the grammar approach compares different possible room configurations through a trial-and-error process to find the most possible one. The proposed method is tested on a real residential building case for validation. The proposed method may be useful in emergent cases when exact floor plans are not available. The method can be extended to other Manhattan-type buildings as long as the grammar rules are settled.

Full-scale load testing of prefabricated combined floor of residential building built of the early 1950s

A detailed full-scale survey of building structures was carried out as a part of scientific and technical support on changing the functional purpose of building premises built in the 1950s. The purpose of the technical condition survey was to assess the bearing capacity of structures and develop conditions for mechanical building safety. Special attention was paid to the study of floor-to-floor overlapping. Over a long period of operation, numerous changes were made to the original structural solution of the building. These changes transformed the design scheme of static work of structures, floors in particular. Due to the multifactorial and difficult-to-control conditions, it wasnt easy to determine the actual bearing capacity of the overlaps with the required degree of reliability using the existing calculation methods. Therefore, in order to confirm the proposed design assumptions, full-scale tests of the overlaps were carried out by loading, which confirmed their bearing capacity determined by the calculation. The conducted field tests made it possible to avoid expensive reinforcement of structures and extend the building life.

Dynamic Characteristics of TAIPEI 101 Skyscraper from Rotational and Translation Seismometers

ABSTRACTContinuous data streams from translational and rotational seismometers installed in TAIPEI 101 enable monitoring of the natural frequencies on different time scales. Using the 2014 seismic data recorded on the 90th floor of this high-rise building and the meteorological data from a weather station located just 1 km away, we explored the characteristics and controlling factors of the ambient vibrations in TAIPEI 101. Using the random decrement technique, the three modal frequencies in translation were identified as 0.15 Hz (F1), 0.43 Hz (F2), and 0.78 Hz (F3). For rotation around the vertical axis, the modal frequencies were 0.23 Hz (R1), 0.59 Hz (R2), and 0.93 Hz (R3). In translation, TAIPEI 101 exhibits a trend of increasing modal frequency with increasing temperature but decreasing modal frequency with increasing wind velocity. The trend with temperature is reversed in rotation motion. The different frequency versus temperature relationship seen for rotational and translational motion demonstrates the importance of introducing rotational motion analysis into structural health monitoring. The change in modal frequencies were also found to decrease with growing amplitude. It is intriguing that F1 exhibits a weaker dependency with amplitude with respect to the higher modes, which may be associated with the suppression of F1 vibration caused by the damper installed in TAIPEI 101. Other than long-term (seasonable) variation, we also highlight the hourly variation of the first-mode amplitude throughout a day by comparing with weather and mobility data. Other than the atmospheric conditions that strongly influence the modal frequencies in long-term behavior, we found that human activities may play an important role in the short-term vibration characteristics of the building.

Study on the Relationship between Indoor Vertical Greening and Oxygen Content in High-Rise Buildings

This article clarifies the quantitative relationship between vertical greening, indoor ventilation, and the oxygen content in high-rise buildings, with the aim of determining values for a high-oxygen-content threshold to assess the ventilation and greening of high-rise buildings. The quantitative index could be provided to architects to assist in the sustainable design of vertical greening in high-rise buildings. The quantitative index offers an effective, convenient, and environmentally friendly oxygen-content-testing method for interior spaces, while avoiding the air pollution caused by the current red phosphorus combustion method. Firstly, a floor of a high-rise building in Harbin was selected for on-site and fixed-point experiments. Secondly, through the design of a candle-burning experiment in a gas bottle, we measured the change in candle-burning time before and after installing vertical greening, as well as under different ventilation states. Finally, the changes in relative oxygen content in each functional space before and after vertical greening and under different ventilation states were statistically analyzed. The results showed that there was a potential correlation between indoor oxygen content and vertical greening placement in high-rise buildings; this correlation was found to be directly related to room orientation, the degree of the plants’ photosynthesis, and indoor airflow. In general, vertical greening should be placed in south-facing rooms. For daily ventilation, two or more windows should be opened to ensure convection in rooms, which can increase their oxygen content.

Influence of built environment on building energy consumption: a case study in Nanjing, China.

Built environment plays a significant role in optimizing building energy consumption. However, few studies have explored the comprehensive effect between built environment metrics on building energy consumption. Thus, this study aims to explore interrelationships between built environment on building energy consumption focused on moderating effect. In this study, we established a built environment measure system from the perspective of land use and land cover, landscape structure and building configuration. This study explored the correlation between built environment and building energy consumption and analyzed the moderating effect of building configuration emphatically. Results show that: for integrated grids group, normalized difference vegetation index (NDVI) and modified normalized difference water index (MNDWI) have a positive influence and impervious area (IA) has a negative influence, with NDVI has the greatest impact. Building floor (BF), building coverage ratio (BCR) and aspect ratio can weaken the positive relationship between NDVI and energy use intensity of grid ( ). BCR weakens the positive effect of MNDWI on . The moderating effect of building configuration on EUI varies in the same grid group and among different grid groups. For sample 1, BCR inhibits the negative effect of mean perimeter-area ration (PARA-MN) on . For sample 2, BF promotes the negative effect of number of patches and land use richness index (R) on . And sky view factor inhibits the positive effect of IA on . This study reveals the pathways of built environment on building energy consumption. As a result, the keys of optimizing building energy consumption are the reasonable planning and optimization of the urban built environment of different land cover. The online version contains supplementary material available at 10.1007/s10668-023-02930-w.

Seismic-induced vibration control of a multi-story building with double tuned mass dampers considering soil-structure interaction

This paper presents a methodology for the optimization of double tuned mass dampers (TMDs) positioned on the top floor of a multi-story building subjected to ground motions considering soil-structure interaction (SSI). In the optimization process, it is considered that double TMDs are connected both in series and in parallel. STMD and PTMD are used to denote the series TMDs and parallel TMDs, respectively. The equations of motion for an n-story shear building controlled by STMD and PTMD are derived by considering the SSI effect and the optimum parameters of both devices are obtained by minimizing the amplitude of the displacement transfer function for the top floor of the building in the frequency domain analysis. The effectiveness of the PTMD and STMD designed using the Jaya algorithm (JA) is verified by numerical examples of a ten-story shear building under twelve earthquake records with different frequency content and the comparison with the traditional TMD is also performed. In order to investigate the effect of earthquake frequency content on the control performance of the TMDs, earthquakes considered are divided into three different groups as low, intermediate, and high-frequency contents. In addition, the influence of the soil stiffness on the optimum parameters and effectiveness of the PTMD and STMD is discussed. Numerical results show that the optimally designed PTMD and STMD effectively suppressed the maximum floor displacements and accelerations of the building. It is also shown that SSI effects can be ignored when the building is built on stiff soil. In addition, it is concluded that the SSI and earthquake frequency content have a significant effect on the control performance of TMDs and the seismic response of the building.

Neighborhood-scale dispersion of traffic-related PM2.5: Simulations of nine typical residential cases from Nanjing

Three-dimensional computational fluid dynamics (CFD) simulations based on the discrete phase model were performed to explore the spatial distribution of traffic-related PM2.5 in summer and winter in nine typical neighborhoods (300 × 300 m) established through investigating realistic samples in Nanjing, China. These cases have different building typologies, building heights, and neighborhood layouts. The focus was on the pollutant dispersion along horizontal and vertical directions and the average near-façade (0.5 m away) concentration of different floors. The harm to residents’ health caused by excessive concentration (>25 μg/m3) was quantified by decrease in life expectancy (DLE). Results show the pollutant dispersion distance along the horizontal direction was limited, up to 100 m; and the concentration decreased, following a nonlinear trend, with increasing height. Façades experiencing excessive concentrations were found to be mainly in the upwind areas for neighborhoods with 3 floor and 6 floor buildings, while in the downwind areas for those with 11 floor and 18 floor buildings. The median DLE was lower than three years, and only a few floor positions experienced a DLE of above 20 years. This study provides insight into pollutant dispersion patterns in typical neighborhoods, which is helpful to improve the early design.

Увеличение этажности жилых зданий как элемент концепции «Компактный город» (на примере Казани)

The concept of “compact city” involves the intensive development of the central and middle zones of large settlements by increasing the efficiency of using the territories that have the greatest value. One of the directions contributing to the implementation of this concept, which consists in the development of the vertical component of the city, increasing the height and number of floors of buildings, is known in geourbanism as “superurbanization”. The increase in the number of floors of buildings is a modern trend in the development of cities in almost all highly urbanized countries. The purpose of this work is a spatiotemporal analysis of changes in the number of floors of residential buildings in the city of Kazan. The authors created a register of housing construction objects in Kazan, built over the period 1860–2016, which contains information about 5317 multi-apartment residential buildings; a thematic map reflecting the distribution of residential buildings in the city of Kazan, depending on the number of floors of these objects, was built. Within the analyzed period, there was a tendency to increase the construction of residential buildings with an increased number of floors, as well as high-rise buildings. The number of high-rise apartment buildings built in 2001–2016 increased especially intensively: their number was 11.4 times higher than the same indicator for 1986–2000. As a rule, spatial differences in the number of floors of residential buildings have a clearly expressed historical conditionality and administrative height regulation: peripheral, relatively young areas (where there is no regulation on building height) are characterized by indicators of the average number of floors of buildings erected there within 12–14 units. High-altitude restrictions during construction in the central, historical part of the city led to lower average number of floors, which is 8 units. This measure is aimed at preserving the unique architectural appearance of historical buildings. The introduction and implementation of the ideas of “vertical” urbanism contribute to the spatial concentration and compact distribution of the activities of the population in the urban space.

Seismic resistance evaluation of multi-story buildings using the modern LIRA-SAPR SP

This article presents the results of evaluating the seismic resistance of high-rise buildings on real records of the accelogram and on regulatory documents using the LIRA-SAPR SP. The maximum and minimum values of bending moments, longitudinal forces, shear stresses are determined, and the most vulnerable areas where cracking in load-bearing structures is possible are determined. It was found that the values of force factors arising in buildings under the action of the accelogram turned out to be 2 times less than the values obtained from the data based on regulatory documents. Along with this, it was found that the results of the calculation for the seismic resistance of high-rise buildings according to real accelerograms and according to regulatory documents showed that the higher the building, the greater the magnitude of displacements, bending moments and longitudinal forces on the upper floors of buildings. This requires the development of appropriate measures to reduce the vibrations of the upper floors of multi-story buildings.

Design of cross-laminated timber (CLT) floors for human-induced vibrations

Cross-laminated timber (CLT) is an innovative engineering wood product made by gluing layers of solid timber boards placed in an orthogonally alternating orientation to the neighbouring layers. CLT panels provide an efficient solution for floors in single and multi-storey buildings. Due to their light weight and often long-span, the design of these floors is generally governed by serviceability limit state criteria, that is, deflection or vibration limits. Vibrations induced by dynamic actions, such as people walking and their everyday activities, cannot result in structural failure but may cause discomfort to occupants if vibrations are not properly controlled. This paper gives an overview of some available methods for the vibration serviceability design of residential CLT floors. Differences between these methods are discussed through the consideration of criteria and their limit values. Although some criteria are common to certain methods, it may happen that the same criteria take into account different factors. In order to get a better description of the actual behaviour of floor structure, certain classifications of floors based on vibration serviceability performance were introduced in design methods.

Simulation case study of stack pressure impact on thermal load in high-rise buildings

The reference building models in the EnergyPlus tool do not consider the stack effect. This is not an issue for small and low-rise buildings. However, this is significant in evaluating the heating and cooling load of high-rise buildings. This study evaluates and quantifies this stack effect in building energy simulation, EnergyPlus. The high-rise commercial building model in the EnergyPlus reference building set was used as a simulation test bed. The vertical multi-stories shaft zones were added inside the core zone in the existing building model. Then, the airflow network model was set in EnergyPlus so the internal airflow including the vertical and horizontal directions through the shaft zone as well as the core and perimeter zones were configured. The simulation model was calibrated against the actual pressure distribution between the core and perimeter zones in all floors of high-rise buildings from the literature. This model calibration was conducted manually by changing the discharge coefficient of the openings between thermal zones. The heating and cooling load of the proposed model were compared to the existing model which does not consider the vertical airflow through the shaft zones. The quantification with relative load mismatch was analyzed by floors and environment including the temperature difference between indoor and outdoor, and wind speed. Moreover, the impact of the air mixing and infiltration on the heating and cooling load was quantified. The result of this study reveals the significance of the stack effect in calculating the heating and cooling load.