Concrete Frame Systems Research Articles

Evaluation of space efficiency criteria in high-rise buildings based on functions: a case study of Türkiye

ABSTRACT High-rise buildings have become a significant solution to address the challenges posed by the rapid growth of urban populations and space limitations in cities. Efficient planning and design of these buildings, aiming to achieve more productivity, can be realized through ensuring space efficiency. This research compares architectural and structural design criteria affecting space efficiency in high-rises based on their functions, aiming to assess the degree of correlation among these criteria, space efficiency, and their interrelations. Currently, no studies examine the differences or similarities in space efficiency of high-rise buildings based on their functions. Additionally, selecting buildings from the same region as samples is a unique aspect of this study. Employing a case study method, the analysis encompasses 42 high-rises in Türkiye, ranging from 100 m to 300 m, and utilizes correlation analysis methods to examine the data. The comprehensive review of space efficiency in high-rises, based on their functions, yielded the following results: (i) Space efficiency ranged from 82.7% to 65.2% in high-rise case studies with different functions, with an average of 73.2%. (ii) A significant majority (83%) of the buildings followed orthogonal designs. (iii) Central core floor planning emerged as the preferred approach. (iv) Increasing elevator density reduced space efficiency. (v) Office buildings favored reinforced concrete frame systems, while residential buildings commonly used reinforced concrete shear wall systems. (vi) As building height increased, elevator and core areas expanded. These findings provide guidance for future high-rise building design and planning.

Deflection Behavior of Reinforced Concrete Beam Frame System with 3/4 Spacing Effective Height of The Beam

Deflection Behavior of Reinforced Concrete Beam Frame System with 3/4 Spacing Effective Height of The Beam

An Investigation of Seismic Behaviour of Prestressed Concrete Frame Structures using Pushover Analysis

Abstract: The prestressed concrete system is a prominent material in civil engineering, with applications ranging from buildings, bridges, foundations, piling, silos, stadiums, roadways, and other infrastructure. However, this work is primarily concerned with its applicability to building frame constructions subjected to seismic loading. The prestressed concrete system for frame constructions not only reduces the amount of structural components, but it is also a cost-effective technology that provides outstanding strength and stiffness, as well as quick and simple site erection. Hence, we will be able to use these prestressed concrete components to their full capacity, unlocking engineering and social benefits that were previously impossible. Prestressed concrete designs, as opposed to reinforced concrete designs, can give structures with substantially longer spans, no cracks, or fewer cracks with tiny crack widths. Nonetheless, research on the seismic behaviour of prestressed concrete frame structures is relatively restricted, with the majority of studies focusing on reinforced concrete structures. Finally, the provisional versions of modern building codes such as ACI 318, GB50010, and EC2 do not provide thorough processes for seismic design of prestressed concrete structures. In this work, the seismic design and behaviour of prestressed concrete building frames are explored using the most recent design code. Three model-building codes will be investigated and compared, including ACI 318- 14, Eurocode 2004-2, and Chinese GB500010-2010. The 10-story prestressed concrete frame system is subjected to gravity and seismic loading, and the strong-column weak beam mechanism is archived to conform with the newly implemented building design code. To examine the behaviour of prestressed concrete frame structures, nonlinear static pushover analysis is used to capture the reaction under earthquake loading. The stiffness and strength needed will be designed in compliance with the three major building codes indicated. In addition, the finite element model will be created using CSI Sap200 to capture its actions.

Progressive Collapse Behavior of a Precast Reinforced Concrete Frame System with Layered Beams

A possible way to improve the structural safety and robustness of precast building structures is to develop effective precast frame systems with layered beams, which combine prefabricated parts with cast-in situ ordinary concrete, high-performance concrete, fiber concrete, or FRP. The paper provides a new type of precast reinforced concrete frame system with layered beams for rapidly erected multi-story buildings resistant to accidental actions. Using a combination of the variational method and two-level design schemes, a simplified analytical model has been developed for structural analysis of the precast reinforced concrete frame system, both for serviceable and ultimate limit states as well as for accidental actions. The proposed model allows for determining shear deformations and the formation and opening of longitudinal cracks in the intermediate contact zone between precast and monolithic parts of reinforced concrete structural elements of the frame, as well as the formation and opening of normal cracks because of the action of axial tensile force or bending moment in these elements. The design model was validated by comparing the calculated and experimental data obtained from testing scaled models of the precast reinforced concrete frame system with layered beams. The paper investigates and thoroughly analyzes the factors affecting the stiffness and bearing capacity of the intermediate contact zone, discusses the criteria for the formation of shear cracks along the contact zone of precast and monolithic concrete, and examines the change in the stiffness and dissipative properties of layered elements at different stages of their static–dynamic loading. The robustness of the experimental models of the structural system was not ensured under the specified load, section dimensions, and reinforcement scheme. Following an accidental action, longitudinal cracks were observed in the contact joint between the monolithic and prefabricated parts in the layered beams. This occurred almost simultaneously with the opening of normal cracks in adjacent sections. A comprehensive analysis of the results indicated a satisfactory degree of agreement between the proposed semi-analytical model and the test data.

Seismic Performance Assessment of Conventional Construction and Ductile Concrete Moment Frames Using Performance-Based Unified Procedure

A Performance-Based Unified (PBU) procedure has recently been proposed by the National Research Council Canada (NRC) to systematically evaluate seismic design requirements available in the National Building Codes (NBC) of Canada. Conventional Construction reinforced Concrete Moment-resisting Frame (CC-CMF) and Ductile reinforced Concrete Moment-Resisting Frame (D-CMF) systems were used in this paper to first assess the proposed PBU procedure and second determine the adequacy of the basis for seismic design requirements in NBC and see its performance margin against different structural performance levels. Results indicate that the detailed screening in the PBU procedure efficiently reduces the number of Incremental Dynamic Analyses (IDA) by more than 60% for CC-CMF while providing remarkable accuracy. It was also found that the CC-CMF system designed for the Normal importance category can provide an adequate margin against Life Safety (LS) performance level objectives, while the D-CMF system designed for the same importance category passes the Collapse Prevention (CP) performance level criteria.

SURVEY AND RECONSTRUCTION OF LOW-RISE REINFORCED CONCRETE FRAME BUILDINGS

This article examined the technical condition of a 2-story retail and household complex located in the city of Tashkent, and provided the necessary recommendations for reconstruction. The building is a reinforced concrete frame system and the survey process used existing methods and computer software.

Evaluating and strengthening low-rise reinforced concrete buildings constructed in Nepal

In Nepal, the reinforced concrete (RC) frame system is commonly used to construct low-rise buildings. In last three decades, a significant number of such buildings were proportioned and constructed in accordance with Nepal National Building Code NBC 205:1994 and NBC 205:2012—also known as the Mandatory Rule of Thumb (MRT). In the aftermath of 2015 Gorkha Earthquake (Mw 7.8) which resulted in large scale social and economic losses, the efforts to formulate improved seismic design provisions led to the development of NBC 105:2020. Considering that MRT-designed low-rise RC frame buildings still constitute a significant part of existing building stock, this study is aimed to conduct a comparative seismic performance evaluation of several case study structures under a comprehensive set of ground motions. Using the nonlinear analysis and seismic fragility assessment of four low-rise RC frame buildings (designed using all three code versions), it is shown that the structural performance and seismic losses can be significantly reduced by following NBC 105:2020 provisions. Several retrofitting solutions are also explored to improve the seismic performance of buildings designed using MRT. It is shown that the concrete or steel jacketing of RC columns can significantly increase the lateral strength and energy dissipation, and reduce the damage probability of such buildings. Lastly, based on the developed results, a machine learning approach is employed to correlate the peak ground acceleration with structural drifts for convenient practical applications.

Numerical Simulation of Soil–Structure Interaction of RC Frame

An Attempt has been made to study the effect of soil media on the response of RC frame structure. Therefore, the present work focuses on the implementation of a two dimensional finite element model of reinforced concrete frame and pile foundation system which explicitly incorporates the soil response. The superstructure members have been represented by means of three-node isoperimetric beam elements with three degrees of freedom per node. The soil mass is idealized by the eight-node isoperimetric quadrilateral element at the near field and five nodes isoperimetric infinite element to simulate the far-field behavior of the soil media. The applicability of this model was demonstrated by analyzing a multi-story building. The results have shown that the influence of the soil behavior on the overall response of the structure.

Experimental and Analytical Investigation of Moment-Carrying Capacities of Reinforced Concrete Frame Systems Corroded by Accelerated Corrosion Method

Technical investigations carried out after the devastating earthquakes in Turkey in the last 25 years show that one of the main causes of damage to reinforced concrete structures is reinforcement bar corrosion. The deterioration caused by reinforcement corrosion in reinforced concrete elements reduces the parameters that define the performance level of the structure, such as ductility, stiffness, bond-slip relationship, load carrying capacity, and energy absorption capacity. Therefore, determining the specified performance levels of reinforced concrete structures exposed to corrosion before any seismic activity occurs is of great importance in preventing loss of life and property. Cross-section behavior in reinforced concrete structures represents the load-bearing element behavior In order to accurately determine the section behavior, the Moment-Curvature relationship must be defined. In this study, the structural behavior of reinforced concrete frames exposed to corrosion was examined experimentally and analytically. For this purpose, 4 of the 5 reinforced concrete frame specimens constructed were corroded at different ratios using the accelerated corrosion method. After the corrosion process was completed, in the experimental part of the study, all specimens were tested under the effect of a 20% constant axial load and reversal-cyclic loading. In the analytical study, as a result of the cross-sectional analyzes carried out by taking into account the material-mechanical properties changing with the effect of corrosion, it was determined that the calculated moment values were in high predicted with the experimentally measured moment values.

Seismic Design of a Typical Mid-Rise Residential Building in Serbia Using Confined Masonry and Reinforced Concrete Frame Systems

Masonry has been widely used for the construction of residential buildings in Serbia and the majority of European countries. Confined masonry (CM) is a contemporary masonry technology that consists of load-bearing masonry walls enclosed in lightly reinforced horizontal and vertical reinforced concrete (RC) confining elements. CM has been widely used for the construction of low-rise and mid-rise residential buildings in Serbia and the region (Yugoslavia) since the 1960s. The design case study of a typical multi-family residential building located in Niš, Serbia (the third-largest urban center in the country), is discussed in this paper. This building was initially designed as a five-story CM structure in accordance with the 1981 Yugoslav seismic design code PTN-S, which was enforced in Serbia until 2019, when the Eurocode was adopted for official seismic design codes. Due to architectural constraints, the original design solution involving the CM system was not compliant with the code; hence, an alternative design using an RC-frame system with masonry infills was adopted. A comparison of two different design solutions provides insight into the different requirements of seismic design codes that have been used in the region. It is important to observe that seismic forces for RC structures determined in accordance with the PTN-S code are considerably lower compared to the ones determined according to EC 8-1, with the ratio ranging from 0.37 to 0.69. The seismic shear force according to Eurocode 8 is 1.46 times higher than the force that was used for seismic design according to the PTN-S code in the case of RC-frame structures. The results of an analysis of CM structures show that the seismic shear force in accordance with Eurocode 8 is almost 2.6 times higher than the force that was used for seismic design in accordance with the PTN-S code. The findings of this study are believed to be useful for understanding the difference in seismic design solutions for previous seismic design codes (which were used in the region for more than 40 years) and the present codes (Eurocodes).

STUDY AND COMPARISON OF STRUCTURE HAVING DIFFERENT INFILL MATERIALS USING ETABS

Reinforcement concrete structure frame system widely used around the world. In building structure, structure element is generally taken as Beam, column, foundation. The dead & live load is transferred from beam to column, column to footing then ultimately load distributed into the soil. The wall load is taken by beam. In building design, we mentioned the whole wall on the beam is possible, if it is not possible, we taken concealed beam into the slab below the wall. During the analysis of frame structure, we consider wall as non-structural element. But including walls in the structure analysis is play important role. This study deals with the examination of the impact of infill in structure and their behaviour in structure. In present situation high rise building constructed with the various type of infill wall materials. Some of them generally use for example red brick, AAC wall, Hollow concrete block, lightweight Aluminium & Steel panels. So three types of models are created on ETABS software. In this study 9 storey high rise building is designed in ETABS with taking 3 infill materials like Fly Ash brick, AAC block and Hollow concrete block taken for study which on the most critical earthquake zone IV analysis (Dynamic) is done using ETABS, soil properties assumed medium and importance factor is taken 1.2 . The all three infill wall models compare with the basic design parameter like moment, shear force, displacement. The all three models that I passed under seismic loading helped me to reach the conclusion on how all three models perform in the case of seismic loading. And by comparing the percentage growth in the displacement and storey drift we can decide the most efficient building. Because the AAC block has the lowest density hence it should have the least moment generated compared to other bricks almost 20-30 percent difference is expected. And the model with Strut member should have least deflection compared to other models. The difference of 15-20 percent is expected atleast. Keywords: ETABS, Structural Analysis, masonry infill, RC frame, earthquake, displacement, drift, base shear, AAC blocks, Hollow concrete block, Bending moment, Diagonal Strut

Survivability of reinforced concrete frame systems with complex stressed elements

Survivability of reinforced concrete frame systems with complex stressed elements

Seismic performance of full-scale self-centering reinforced concrete beam-column joints: Experimental, numerical and theoretical analysis

A reinforced concrete (RC) frame system with a self-centering joint connected with post-tensioned (PT) tendons and bolted angles was developed to overcome the limitations of precast system without reliable connection. The self-centering beam-column joints with a gap at the beam-column interface are capable to resist severe earthquake with negligible residual deformation and minimal mechanical damage. However, a comprehensive understanding on effect of joint connectors including bolted angles and PT tendons on the seismic performance of self-centering joint (SCJ) is lacking. Three full-scale SCJ specimens were thus designed and tested under cyclic loading to determine the mechanical performance of SCJ and its influencing factors. The effects of bolted angles as energy dissipater and PT tendons as displacement controller were separately explored. The structural performance of SCJ was analyzed by finite element model, showing good agreement with the experimental results. A parametric study was conducted to further analyze the contribution of PT force and bolted angle to hysteretic response. Finally, the lateral load model of SCJ was established and the contribution of bolted angle and PT tendon was theoretical studied. The results indicate that the component elements (beam and column) remained undamaged after cyclic test, while the bolted angles experienced large deformation, dissipating substantial seismic energy. The gap at the beam-column interface of joint equipped with PT tendons was closed and the joint was perfectly self-centered by PT force exhibiting minor residual displacement after unloading. The PT tendons and bolted angles cooperated well, which enable the SCJ to be used as a connection in RC frame at high seismic region. Furthermore, the validated numerical model can be further used to predict the seismic performance of similar types of beam-column joints. The simplified analysis model can provide a potential design reference in the application of RC self-centering systems.

Efficient seismic fragility analysis method utilizing ground motion clustering and probabilistic machine learning

Machine learning (ML) techniques have been recently adopted in engineering practice to define the relationship between seismic intensity measure (IM) and structural damage measure (DM) based on a limited set of numerical simulations. However, they only offer deterministic prediction, which failing to reflect the aleatoric uncertainty related to input variables (e.g. seismic excitation and structural properties) and the epistemic uncertainty associated with modeling. This paper proposes a probabilistic ML method combined with ground motion clustering for seismic fragility analysis of structures. In the probabilistic ML method, by the natural gradient boosting (NGBoost), the conditional probability distribution can be evaluated for each structural response instead of producing point estimation. In addition, ground motion clustering is based on the time series K-means, which can capture the hidden features and select the representative subset of ground motions. The proposed framework was implemented for seismic fragility analysis of a typical 3-span, 6-storey reinforced concrete (RC) frame system. Analysis results indicated that the point estimation accuracy of the NGBoost was comparable to that based on excellent deterministic ML techniques, e.g. artificial neural network (ANN), random forest (RF), extreme gradient boosting (XGBoost). Moreover, the probabilistic prediction can efficiently provide the conditional probability of exceeding a damaged state in the structure given an IM level, eliminating the need for additional input of uncertainties from structural properties in traditional ML methods. Ultimately, the cluster-based ground motion selection reduced the model uncertainty and improves the prediction accuracy of the probabilistic ML model.

EVALUATION OF RETROFIT EFFECTIVENESS AND COST IMPLICATIONS OF MRF STRUCTURES USING DISTINCT FRCM COMPOSITE SYSTEMS

This paper summarizes the results of a numerical investigation to assess the effectiveness of retrofitting pre-seismic code concrete framing structural systems using two distinct fiber-reinforced cementitious matrix (FRCM) composites. While FRCM composites were focused in the literature at the member level, this study focuses on implementing this retrofit technique effectively at the structure level. Several static pushover analyses (SPAs) and inelastic dynamic simulations (IDSs) are carried out for FRCM-retrofitted RC frames representing the lateral force-resisting system of a moment-resisting frame (MRF) structure. Correlating the numerical simulation results and experimental results obtained from another study verified the selected fiber discretized section modeling technique for FRCM retrofitted MRFs and reflected the effectiveness of the adopted approach in prolonging local and global damage states. The verified modeling technique of the risk-mitigation measure is then employed to evaluate the performance of an upgraded RC building using three-dimensional fiber-based numerical models. Finally, a parametric study using SPAs and IDSs using multiple seismic scenarios is conducted to select the most effective FRCM retrofit material for the seismic performance enhancement of the benchmark structure. The study concludes that using the selected FRCM retrofit technique effectively mitigated the structural collapse damage state of the substandard building at the design and maximum considered seismic intensity levels by 28% and 32%, respectively.

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

Optimization of reinforced concrete frame structures and matrix displacement method

In this study, reinforced concrete frame system is generated, and all structural elements which are beam and columns are optimized according to the applied distributed loads and different concrete classes by using Matlab program. Jaya algorithm which is a Metaheuristic Algorithm that enables to optimization process and finds the best cross sections, reinforcement area as well as cost of the system, is proposed. It is observed that cross-section, reinforced area as well as cost of the system are changed when concrete classes are used differently. After finding the optimum design values for frame system, the matrix displacement method is utilized to specify the system displacements and all nodes forces. Furthermore, columns and beam displacement results are not similar, and also internal forces are different for nodes. TS500 (2000) (Reinforced concrete structures design and construction rules) and TBDY (2018) (Turkey Building Earthquake Regulation) are used together to specify variables, constraints and also necessity values. The proposed method is feasible for frame structures consisting of different members.

ANALISIS STRUKTUR KOLOM PADA GEDUNG PARKIR RUMAH SAKIT DI SEMARANG

The parking building of Hospital Semarang is a space frame system that is assumed to be on soft soil (SE) and analyzed based on the Special Moment Reinforced Concrete Frame System (SRPMK). With quality concrete, fy=25 MPa, reinforcing steel quality, fy=420 MPa, and reinforcing steel quality, fy=280 MPa. Load analysis refers to SNI 1726 – 2019, and concrete regulations refer to SNI 2847 – 2019. Based on the results of the dynamic response analysis obtained from the program ETABS v19.1.0 follows the requirements of the variety of motion, with mode 1 showing the direction of translational motion X direction, which is 49,9%, mode 2 shows the translational movement in the Y direction which is 71.24%. Mode 3 shows the movement of the structure in the rotation, which is 57.72%. Dynamic base shear, 2393,984 kN, and 2743 4332 kN have met the requirements, reaching 100%. The earthquake direction applied was in the orthogonal direction with a redundancy factor value (ρ) of 1.3. There is no deviation between levels that exceed the allowable limit. P-Delta checking of the structure concluded that the structure remains stable. The results of the analysis of the cross-sectional capacity of the column obtained from the spColumn v6.00 program can be concluded that for a column with dimensions of 600x800, it is not strong enough to withstand the working load, because the minimum load is within the design strength of the interaction diagram. The maximum load is outside the strength of the interaction diagram plan. While the column with dimensions of 600x600 is still vital to withstand the working load because the minimum and maximum loads are in the strong interaction diagram plan.

Ponašanje jednorasponskoga dvoetažnog betonskog okvira armiranog bazaltnim vlaknima

This study focuses on structural design, which is a primary aspect of civil engineering. Investigating the behavior of reinforced concrete (RC) frame systems subjected to lateral loading and estimating the damage state of a structure still remain challenging tasks in civil engineering. Reinforced concrete is currently used in a majority of constructions and Conventional buildings remain vulnerable to seismic earthquakes. The aim of this research is to identify how well RC frames with basalt and steel fibers perform under cyclic loading. Steel and basalt fibers are chopped to a size of 2.5 cm. The reinforcements details are made according to IS 13920-2016. The concrete specimen used for this work is in the form of a single-bay, two-story frame, which is composed of reinforced concrete along with chopped steel and basalt fibers of two different proportions. Three frames are cast. One is a RC concrete frame with no fiber materials (conventional concrete) and the other two frames are cast with different proportions of fiber content. The basalt fiber is added to the specimens in proportions of 0.25 % and 0.50 %. The experimental outcome attained from the specimens of 0.25 % of basalt fiber has superior load-carrying capacity as well as minimum story drift than the other two frames. The ductile behavior of BFRC is increased compared to that in conventional ones. It is observed that the crack width of the BFRC is less when compared to that in the conventional concrete.

Seismic Response Analysis of Steel–Concrete Composite Frame Structures with URSP Connectors

The uplift-restricted and slip-permitted (URSP) connector is a new type of connector used in steel-concrete composite structures that has been proven to improve the structural performance of negative moment regions. Since this connector changes the interface restraint between the slab and steel beam, there is an imperative to study the seismic performance of steel-concrete composite frame systems with this new type of connector. In this study, the dynamic behavior of composite frame structures with URSP connectors under seismic loads was numerically investigated. First, a beam-shell mixed model was used and complex interfaces of different connectors were considered while establishing a numerical model to conduct elasto-plastic time history analysis under various seismic loads. This numerical model was validated with the frame sub-assemblage experimental results of quasi-static cyclic tests. Second, the model analysis results of structures with URSP connectors were obtained and compared with those of traditional structures. Third, dynamic response results including roof displacement, inter-story displacement, and the distribution and failure modes of plastic hinges were analyzed and compared. The comparisons indicated that the arrangement of full-span URSP connectors had a non-negligible influence on the dynamic behavior of the systems. The arrangement increased the maximum inter-story displacement by 31.5% and induced adverse effects in certain cases, which is not suggested in the application of URSP connectors. The partial arrangement of URSP connectors had little influence on the dynamic behavior of the systems, and the frame systems still showed a good seismic performance, which was the same as the traditional composite structural system. These findings may promote the application of URSP connectors in composite structures.