Frame Buildings Research Articles

Wind influence numerical simulations on stadium structures in RWIND module of the DLUBAL RFEM software

This paper examines the effect of wind load on the stadium building, designed as a possible replacement for the stadium in the city of Mariupol, which was destroyed as a result of hostilities. The problems of using domestic standards in the design of stadium structures are considered. The approach of European regulatory documents to taking into account the effect of wind influence is considered. An analysis of previous scientific studies concerning the determination of aerodynamic parameters for stadium structures has been carried out. An analysis of the domestic regulatory document regulating the collection of wind loads showed the need for additional research into the aerodynamic parameters for stadium structures. Using a special RWIND module as part of the Dlubal RFEM software package, numerical modeling was used to simulate the wind flow flowing around the model of the stadium building, which best corresponded to the adopted design decisions, as if it were carried out in a real wind tunnel. A project was considered for an ellipsoidal stadium, the configuration of the stands and the covering of which is a full bowl with an incomplete covering. The covering over the stadium stands is designed in the form of a canopy formed by cantilever flat steel trusses. The basis of the stadium building frame is made up of vertical steel frames with a rigid connection of nodes, to the central post of which cantilever trusses of the canopy are attached. The result of theoretical testing of the stadium model was distribution diagrams of aerodynamic coefficients, the maximum values of which were used to further determine the values of wind pressure on these structures. An analysis of the research results was was carried out. The use of numerical simulation tools for wind flows made it possible to increase the complexity of the system both at the level of the design solution and at the level of the calculation model. Analysis of the design solution allowed us to competently select the necessary design solutions for load-bearing structures, taking into account the requirements of current design standards and Eurocode 1 regulations.

Stress-strain state of building structures taking into account possible local failure of the element

The issue of choosing a structural design and material for supporting structures is an important technical and economic task at the stage of developing a design solution. It depends on a number of factors: consequence class of the structure, reliability of the design solution, savings in basic building materials. The publication provides a classification of design schemes and types of load-bearing structures used in the corresponding solutions. The disadvantages and advantages of using prefabricated and monolithic structures for the installation and subsequent operation of the structural scheme of buildings and structures are considered. Modern design requirements include ensuring the ability of a damaged structure to adapt to new conditions while continuing to function while ensuring the integrity of human life, property and equipment. New conditions mean the consequences of the occurrence of a certain emergency situation, accompanied by weakening or overloading of the load-bearing structures of a structure or soil foundation: a change in the structural design, a combination of new existing loads and a redistribution of internal forces. The publication reflects the results of assessing the redistribution of the stress-strain state of the elements of the “base - foundations - load-bearing structures” system as a result of the implementation of a hypothetical emergency situation with the exclusion of the load-bearing structure from operation. The case of the collapse of one of the vertical load-bearing elements (local failure of the pylon) of an underground floor, which can be used as a dual-use structure, is considered. Calculations for the stability of the structure against progressive collapse were carried out by numerical modeling in the LIRA SAPR-2019 software using a quasi-static calculation and the method of direct integration of dynamics over time. It has been demonstrated that the method of numerical modeling the joint work of a building with a soil base affects the results of a calculation of the progressive collapse of the building frame. The influence of local collapse of a vertical load-bearing element on the redistribution of stresses and strains in the foundation structures of a building section is assessed. The load on the piles under the pylons around the element removed under the local failure scenario is expected to increase by 15...25%.

Installation of portals in the sections of the column demolition during the re-equipment of Tagmet JSC workshops

Introduction. The article presents the materials on the activities, carried out in the pipe rolling shops of the Tagmet JSC during the modernization period, starting from 2007. The Research Institute of Building Constructions named after V.A. Koucherenko, conducted prolonged surveys of plant workshop structures in order to issue conclusions on their industrial safety and recommendations for the repair and strengthening of damaged elements in building structures for their further safe operation, including workshops, where the technological process has been changed due to the installation of new equipment.Aim. To demonstrate one of the ways to reconstruct industrial buildings using the example of workshops, located in the territory of the Tagmet JSC, based on a survey of combined structures, calculations and analyzes of their bearing capacity margins.Materials. The article provides the drawings of original metal structures and photographs of steel structures, already built to reinforce them and change the existing parameters of the building frame to suitable ones for new operating conditions.Results. Recommendations for structural strengthening, applicable for similar activities, are given. Due to the scientific and technical support for the design and construction of three modernized Tagmet workshops, the plant continuously increased its productivity in subsequent years.Conclusions. No defects and damage, which exceed the values, established by the current regulatory documents, and affect the operational suitability of buildings, were revealed during the inspection and operational safety examination of Tagmet plant structures. The results of the calculations, performed to the portal structures at the column demolition sections of the plant workshop building frames, proved the assurance of their strength and stability. The design solutions were successfully implemented during the reconstruction of workshops at the Tagmet JSC.

Comparison of 5 and 10 Storey Frame Buildings and 5 and 10 Storey Shear Wall-Frame Buildings Under the Effect of Maras Earthquake According to the Turkish Building Earthquake Code 2018

In this study, the differences in the displacements, base shear forces, relative storey drifts and foundation stresses under different earthquake data on different storeys of shear wall frame systems and framed systems are investigated by using SAP2000 program. Within the scope of the study, four buildings with 5-storey frame, 5-storey shear wall frame, 10-storey frame and 10 storey shear wall frame are modelled. All four buildings were designed to be identical with 4 spans in X and Y directions and each span was designed as 5 meters. The height of each floor is designed as 3 meters for all four buildings. In sheared structures, shear walls are designed to be 4 meters from the corner columns to the columns closest to them. The earthquake data to be influenced on all four structures are the earthquake data from the Earthquake Hazard Map of Turkey published by AFAD at the coordinates of 41° latitude, 27° longitude of Kırklareli province, Luleburgaz district. Another earthquake parameter was taken from station 4615 during the earthquake in Kahramanmaras. The data recorded by station 4615 for the 7.6 Mw earthquake in Kahramanmaras was applied to all four structures. These two earthquake data were imposed on these four structures in order to compare the resulting displacements, relative storey drifts, base shear forces and foundation stresses. Since the structures are all symmetrical in both X and Y directions, only one direction of the displacements was calculated. As a result, when both the earthquake data from the Earthquake Hazard Map and the Kahramanmaras earthquake data were applied to these four structures, it was observed that the maximum values of the displacements occurred at the top floors of all structures and the effect of the Kahramanmaras earthquake data was higher in the displacements, relative storey drifts, base shear forces and foundation stresses than the effect of the other earthquake data.

Seismic Behaviour of RC Framed Building Supported on Combined Piled Raft Foundation in Sandy Soil

Seismic Behaviour of RC Framed Building Supported on Combined Piled Raft Foundation in Sandy Soil

Bayesian structural model updating with multimodal variational autoencoder

A novel framework for Bayesian structural model updating is presented in this study. The proposed method utilizes the surrogate unimodal encoders of a multimodal variational autoencoder (VAE). The method facilitates an approximation of the likelihood when dealing with a small number of observations. It is particularly suitable for high-dimensional correlated simultaneous observations applicable to various dynamic analysis models. The proposed approach was benchmarked using a numerical model of a single-story frame building with acceleration and dynamic strain measurements. Additionally, an example involving a Bayesian update of nonlinear model parameters for a three-degree-of-freedom lumped mass model demonstrates computational efficiency when compared to using the original VAE, while maintaining adequate accuracy for practical applications.

Prolonged Carbon Storage and CO2 Reduction by Circular Design with Wood

The benefits of circularity and biogenic carbon storage are often overseen. This study links the circular design of buildings with prolonged biogenic carbon storage. Circularity in architectural design can involve extending the service life of a building frame, whilst forests grow back and store more carbon. Following this approach, Stora Enso has developed a mixed-use building concept with flexible and adaptable structures. Static and dynamic life cycle assessment (LCA) has been carried out to assess different scenarios, modelling and quantifying its potential benefits regarding whole life carbon. While whole life carbon is lower in all timber scenarios compared to conventional concrete buildings, dynamic LCA makes clear the benefits of carbon storage and carbon sequestration. Total emissions, considering a reference service life of 50 years, are 2,84 kg CO2-eq./m² floor area/year, considering biogenic carbon storage and carbon sequestration in regrowing forests. An increase of the building lifetime to 80 years aligns with a longer rotation time of forest trees, resulting in whole life carbon of -0,09 kg CO2-eq./m² floor area/year. This demonstrates that the effective implementation of built-in flexibility and adaptability can extend the service life of a building, unlocking environmental benefits of biogenic carbon storage of wood products in buildings.

Seismic Response Analysis of Steel Structure Isolation System Under Long-Period Seismic Motion

To analyze the seismic response of steel structure isolation systems under long-period seismic motion, a 9-story steel frame building was selected as the subject. Five steel structure finite element models were established using SAP2000. Response spectrum analysis was conducted on the seismic motion to determine if it adhered to the characteristics of long-period seismic motion. Modal analysis of each structural model revealed that the isolation structure significantly prolonged the structural natural vibration period and enhanced seismic performance. Base reactions and floor displacements of various structures notably increased under long-period seismic motion compared to regular seismic activity. Placing isolation bearings in the lower part of the structure proved more effective under long-period seismic motion. In seismic design engineering, it is essential to consider the impact of long-period seismic motion on structures and the potential failure of isolation bearings.

Seismic collapse fragility analysis of steel moment-resisting frames (MRFs) with stiffness and strength deterioration considering the spectral shape of ground motion records

In this paper, the seismic collapse fragility analysis of special steel moment-resisting frame (MRF) buildings with strength and stiffness deterioration is comprehensively evaluated, taking into account the effect of record selection based on the spectral shape parameters. For this purpose, three special steel moment-resisting frame buildings, including 3, 10, and 20-story structures as representatives of low-rise, mid-rise, and high-rise buildings, are investigated. The modified bilinear Ibarra-Medina-Krawinkler (IMK) relation is used for modeling the concentrated plasticity and considering cyclic degradation in beams and columns under earthquake effects in Incremental Dynamic Analysis (IDA). The ground motion records are selected and categorized based on the three parameters, including the epsilon, SaRatio, and Np from a large database consisting of 2000 earthquake records. The records are divided into 7 groups using the epsilon parameter. The SaRatio and Np parameters further divide the records into 5 categories. Additionally, a randomly selected set of 200 earthquake records is used. The effects of hysteretic deterioration and spectral shape parameters of earthquake records on the median IDA curves, collapse fragility curves, and collapse capacity of the steel MRF structures are investigated. In addition to the hysteretic deterioration of steel structural members based on the results of the previous experiments, different values of the deterioration parameter (λ) are used in the nonlinear time history analyses to parametrically study the effect of deterioration on the collapse capacity. Finally, the effect of various parameters on the seismic collapse capacity of the structures in the form of Tornado diagrams is illustrated. The results demonstrate that the randomly selected records yield results close to the records sets with Np = 1, SaRatio = 1, and ε = 0. Furthermore, for a constant deterioration level, increasing epsilon and SaRatio, and decreasing Np lead to an increase in the collapse capacity of the structures. The results also show that the effect of deterioration on the collapse capacity of the buildings, especially the low-rise 3-story building, is significant.

Inter-Storey Drift for Base Isolated R.C. Frame Buildings

Inter-Storey Drift for Base Isolated R.C. Frame Buildings

Directional alongwind and crosswind effects on the performance of a 15-storey steel braced frame building in seismic environment

The effect of crosswind loads on buildings has been studied since the 1980s, but only a few researchers reported on the nonlinear response of tall buildings under ultimate crosswind loads. Performance-based wind design procedures provide a structurally efficient and economical alternative to prescriptive code based design, however their establishment necessitates further research in the following areas: i) development of a straightforward procedure for the derivation of reliable wind time-history loadings from wind tunnel data; ii) assessment of the dynamic behavior of tall buildings excited by wind in the full range of response: linear-nonlinear-near collapse; and iii) quantification of the effect of directionality on building performance in the full range of response. Herein, local aerodynamic data are used to produce reliable estimations of the directional alongwind and crosswind time-history loadings for a 15-storey steel braced frame hospital building, in Montreal, Canada. The case study is designed to withstand the code-based wind and earthquake loads, as independent load combination cases. Then, advanced finite element models are employed to assess the effect of directional alongwind and crosswind loads on the building performance under increasing levels of input wind motion. Ten excitation angles from 0° to 90° are considered. Incremental dynamic analysis is employed to assess the building performance under recurring winds, including the wind directionality effect. To monitor fatigue failure, the rainflow counting method is used to approximate the number and amplitude of loading cycles exhibited by ductile brace members of the lateral force resisting system.

Robustness of reinforced concrete frames with elements experiencing bending with torsion

The article presents the results of experimental and theoretical studies of deformation, cracking and fracture of frame structural systems under accidental impacts. The elements of frame structures may exhibit bending with torque as a consequence of the occurrence of an abnormal event. The study provides an energy-based approach to determining internal forces in such structural systems under a scenario in which a column is removed. It also presents a computational model that evaluates the robustness of a reinforced concrete frame of a multi-story building. The model permits the determination of dynamic effects within a structural system, at varying levels of static loads acting within it, and enables the investigation of deformation patterns within the spatial cross-section, including those experiencing bending and torsion. It also allows for the calculation of the robustness parameter of frame systems. In order to validate the proposed computational model, the study employs the outcomes of tests conducted on scale models of reinforced concrete frames with beams subjected to bending and torsion. The experimental frames were loaded in two stages. In the initial stage, the frame structures were subjected to static loading. At the second stage, scaled models were exposed to dynamic loading, which was caused by the sudden removal of columns. A comparison of calculated and experimental results for the investigated structures demonstrates the reliability and efficiency of the proposed calculation model. Consequently, it can be used to calculate the progressive collapse resistance of reinforced concrete frames of multi-storey buildings.

Database of tall pre-Northridge steel moment frames for earthquake performance evaluations

This article describes a detailed database of tall steel moment frame buildings that are representative of the construction practices in San Francisco prior to the 1994 Northridge earthquake. The database contains design details that affect the structural performance of steel moment frames, including frame geometry, member cross-section sizes, and gravity system characteristics. This database also captures irregularities that might impact seismic response, such as podiums, setbacks, mass concentrations (mechanical, electrical, and plumbing (MEP) floors), interrupted column lines, and atriums. The database includes information on 89 moment frame buildings, 14 of which were built before 1960 and are constructed with riveted connections, while the remaining 75 have welded flange connections like those that suffered brittle fracture during the 1994 Northridge earthquake. The buildings are further distinguished between space frame, perimeter frame, and partial space frame systems. For about half (41/89) of the buildings in the database, section sizes of representative structural members were collected, which enabled the evaluation of the seismic design, elastic, and inelastic response using computational workflows. The design diagnostics indicate that most of the buildings meet the minimum seismic strength and strong-column weak-beam requirements of modern building codes, even though they were not necessarily designed with this intent. On the contrary, about one-third of the buildings do not meet the seismic design drift limit of current codes, and about half of them have weak beam-column panel zones. This database, associated structural analysis models, and processing scripts are published at DesignSafe https://doi.org/10.17603/ds2-wjad-r340 to facilitate collaboration and continued development of open-source data for high-resolution simulations to inform risk mitigation strategies on a regional scale.

Seismic Response History Analysis of RC Frame Building with Different Position of Shear Walls by using ETABS

Seismic Response History Analysis of RC Frame Building with Different Position of Shear Walls by using ETABS

Method to identify if torsional mode of a building is its first mode

Torsionally flexible buildings (that have torsional mode as fundamental mode) twist during earthquake shaking, and may collapse partially or completely depending upon the direction and level of shaking. The problem is aggravated when the building is torsionally unsymmetrical. Some design codes (like Eurocode, Indian Code) explicitly prohibit the design of such buildings. This paper presents a simple approximate method to identify torsionally flexible RC Moment Frame and RC Structural Wall buildings at the initial proportioning stage itself without carrying out a detailed structural analysis. It is possible to identify whether or not the first mode is torsional mode of a building (i.e., torsionally flexible building) if Natural Period Ratio τ>1 by modelling the building with rigid diaphragm and distribution of mass & stiffness along the height of building, and estimating: (1) radius of gyration of rotational mass rm of each floor plan geometry by lumping the masses of slabs, beams and all vertical elements at each nodes, (2) radius of gyration of twisting stiffness rKθ of all vertical elements using their translational and torsional stiffnesses (considering flexibility of adjoining beams and vertical elements accounting for both flexural and shear deformations), and (iv) τ (=rm/rKθ). The method is validated with 3D Modal Analysis (using τ =Tθ/T, where Tθ is Uncoupled Torsional Natural Period and T Uncoupled Translational Natural Period) of hypothetical buildings using a commercial structural analysis software. Also, parameters are identified that lead to τ>1, and solutions suggested to avoid torsional flexibility in buildings. Further, the method helps identify vertical stiffness irregularity in buildings. Draft provisions are suggested for inclusion in seismic codes. Also, poor performance of multi-storey building (with τ>1) is demonstrated using nonlinear static and nonlinear time history analyses.

PROCEDURE FOR TECHNICAL SURVEY OF BEARING STRUCTURES OF MULTISTORY BUILDINGS CONSTRUCTED TAKEN INTO ACCOUNT OF THEIR EARTHQUAKE RESISTANCE

This article describes in detail the procedure and sequence of survey the technical condition of frame buildings made of multi-storey reinforced concrete structures.

Study on Non-Linear Behavior of Unstiffened Steel Plate Shear Walled Building Frames

Study on Non-Linear Behavior of Unstiffened Steel Plate Shear Walled Building Frames

Seismic design optimization of space steel frame buildings equipped with triple friction pendulum base isolators

To increase the seismic resilience of structures, it is necessary to utilize seismic isolation to increase structural periods and reduce story drifts. When seismic isolation is implemented, structures are capable of deforming by remaining within safe limits. Thus, more seismically resilient designs are achieved compared to conventional fixed-based structures since lighter structural design weights are attained. The principal aim of this study is to achieve the comparative design optimization of space steel frame buildings equipped with seismic base isolation and to examine the effect of seismic base isolation on optimum structural design weight by comparing the same structures with conventional rigid-based ones. For seismic base isolation, triple friction pendulums are implemented into steel frame buildings. For this aim, four different space steel frame buildings with 4-, 6-, 8-, and 10-story are treated as design examples. A novel design optimization algorithm is encoded, which includes nature-inspired metaheuristic artificial bee colony, crow search, and Archimedes optimization algorithms to achieve design optimizations of triple friction pendulums equipped with seismic-isolated space steel frame buildings. The practice code provisions of load and resistance factor design specification for structural steel buildings have been applied to control the structural design constraints of inter-story drift, top-story drift, strength, displacement, and connections geometry of beams and columns. Eventually, it has been remarked that seismic base isolation significantly reduces the structural optimal design weight of space steel frame buildings.

Development of Seismic Fragility Functions for Reinforced Concrete Buildings Using Damage-Sensitive Features Based on Wavelet Theory

In this study, wavelet-based damage-sensitive features are employed to derive the seismic fragility functions/curves for reinforced concrete moment-resisting frames. Two different wavelet transform functions, namely, Bior3.3 and Morlet mother wavelet families, were applied to absolute acceleration time histories of building frames to extract the wavelet-based and refined wavelet-based damage-sensitive features (i.e., DSF and rDSF). The accuracy of seismic assessments and certainty in predicting structural behavior strongly depend on the specific optimal intensity measures selected, reliability of wavelet-based damage-sensitive features, and some such intensity measures as PGA, PGV, PGD, Sa, and Sdi as the conventionally utilized measures to detect the damage state of a structure. These measures were examined against their statistical properties of efficiency, practicality, proficiency, coefficient of determination, and sufficiency to select the appropriate optimal intensity measures, which were then used to drive the fragility curves disclosing the failure or other damage states of interest. For the purposes of this study, three different concrete moment-resisting frames with four-, eight-, and twelve-story building frames were adopted for implementing the proposed approach. The findings demonstrate that the wavelet-based damage-sensitive features (DSFs/rDSF) simultaneously satisfy all the statistical properties cited above. This is evidenced by the low variance and dispersions observed in the frame damage state predictions by the fragility functions derived from the wavelet-based DSF when compared with those derived from the classical fragility analyses such as spectral acceleration at the first mode period of the structure. A final aspect of the study concerns the superior performance and efficiency of the fragility curves derived by the Bior3.3 wavelet-based DSF over those derived from Morlet wavelet-based DSF.

Assessing the Impact of Ground Motion Duration on Losses in Typical Modern Steel Moment Frames

This research was undertaken to study the duration effects on the seismic economic risk of steel moment frame (SMF) buildings, a prominent class of buildings in commercial stock. Firstly, a modified version of FEMA P-695 ground motion scaling, tailored for seismic loss estimation purposes and incorporating two sets of spectrally matched bi-directional short- and long-duration ground motions, is proposed to study code-compliant plan-symmetrical SMFs with different heights (i.e., two to 20 stories). It is shown that long-duration ground motions increase the collapse risk of SMFs, on average, by 28.0% at the MCE level. Next, a component-based loss estimation methodology was adopted for evaluating the seismic losses under each set of ground motions. These losses are studied separately for building components (i.e., structural and nonstructural) and contents. Moreover, we propose an approach for calculating average annualized loss (AAL) as a prominent risk meter that segregates contributions of short- and long-duration ground motions to attain hazard consistency. Loss analyses showed the minimal impact of building height on the contribution of these two types of earthquakes. The seismic risk analysis of buildings also revealed that collapse risk is influenced mainly by duration effects followed by building and content losses.