Multi-storey Frame Structures Research Articles

A cradle-to-site life cycle analysis of laser-cut passing-through tubular joints under different seismic conditions

Steel circular hollow sections (CHS) offer a number of advantages compared to their open section counterparts such as better resistance under tension, compression, bending in all directions and an overall reduction of structural weight, required material for corrosion and fire protection. Nevertheless, the traditional methods to connect open section beams to CHS columns often demand a significant amount of fabrication work, leading to high expenditure and resource consumption – therefore limiting their use in the current industry. These issues can be solved with an automatized joint fabrication. To that purpose, this article proposes two innovative “passing-through” I-to-CHS joints, achieved via laser cutting technology (LCT). Experimental and numerical studies were conducted to assess the joint fabrication aspects as well as the structural performance of the proposed joints. The results showed that the proposed joints can offer respectively 2.5- and 10-times larger strength and stiffness properties compared to a conventional directly welded I-to-CHS joint having similar section properties for the beam and the column. However, this study focuses on the environmental sustainability and economic feasibility of the proposed joints. A cradle-to-site life cycle analysis is conducted using multi-storey frame structures. The environmental and economic impact of the proposed joints are compared with different types of existing I-to-CHS joints in order to assess their possible benefits and limitations. Thanks to the savings in the raw material, surface treatment and transportation resources, it could be stated that, the passing-through approach with LCT offers approximately 32−42% reduction in the construction and fabrication costs of the multi-storey structures while reducing the CO2 emissions by 24−28%, compared to the directly welded I-to-CHS joints.

Seismic Performance of Ordinary and Damage-tolerant Concrete Beam-column Joints under Reversed Cyclic Loading

The adoption of the capacity design principle in modern codes of practice allows for multi-storey frame structures to exhibit ductile behaviour in a major earthquake without collapsing. Whilst the risk of shear failure in regions of large inelastic deformation can be largely reduced, the detailing requirements in capacity design often leads to reinforcement congestion that adds difficulty during the construction process, due to the high amount of transverse reinforcement required to provide shear resistance and confinement. The work presented in this paper forms a part of a wider research programme that aims to simplify the detailing requirements of transverse reinforcement in the joint and plastic hinge regions of moment-resisting frame structures. To this end, damage-tolerant concrete known as engineered cementitious composite (ECC) was used to substitute concrete in these critical regions. In this article, the results of reversed cyclic tests on two half-scale exterior beam-column joints, constructed with ordinary concrete and ECC, are presented. Key features of the response such as the reversed cyclic hysteresis loops, stiffness degradation and cumulative energy dissipation are discussed, along with crack development under reversed cyclic loading in the form of digital strain maps.

Dynamic progressive collapse response of multi-storey frame structures with masonry infills

The response of reinforced concrete (RC) frame building structures to exceptional events like explosions or impacts causing the loss of a primary structural element depends on the robustness of the structural configuration. In the case of a sudden column loss, the resisting mechanism of the involved spans substantially changes, while a progressive collapse mechanism can develop under the arising dynamic loads. The presence of masonry infill walls can substantially modify the overall response to a sudden column loss scenario. In this context, this paper investigates the response of reinforced concrete frame structures undergoing instantaneous column losses in order to assess the influence of masonry infills on the progressive collapse response under dynamic load demands. A recently formulated equivalent-strut macro-modelling approach is employed to reproduce the mechanical interaction between infill walls and the frames. A ten-storey, six-bays 2D reinforced concrete frame is selected as a case study structure considering different reinforcement layouts (seismic or non-seismic design) and column loss scenarios (central column or corner column loss). The simulations are carried out using the fiber-section beam/column elements available in the OpenSees software platform, as they can account for the arching mechanism developing in the post-cracked regime. The dynamic responses of the case-study tests to the sudden column loss scenarios are assessed with and without the inclusion of masonry infills within the structural models. Results demonstrate that masonry infills introduce a substantial modification of the resisting mechanism and of the dynamic response, limiting the propagation of progressive collapse in most of the considered cases.

Behaviour and design of coupled steel-concrete composite wall-frame structures

This paper explores the lateral load-carrying behaviour of coupled steel-concrete composite (SCC) wall-frame structures, which comprise concrete-filled steel tubular (CFST) columns, composite beams and composite walls. Both experimental and numerical studies were conducted. The experimental programme includes one single-storey bare frame structure and three single-storey coupled SCC wall-frame structures. The experimental results showed that applying the composite wall can significantly increase the lateral load-carrying capacity of the entire structure. It was also evident that increasing the wall width and lowering the structural height can effectively enhance the lateral load-carrying capacity. The modelling approaches in ABAQUS and OpenSees were proposed to conduct the finite element (FE) analysis. In particular, ABAQUS was used to build single-storey coupled SCC wall-frame structures to assess the effects of several parameters, such as beam stiffness, the thickness of steel tubes and wall faceplates, wall width, concrete grade, steel grade and axial load ratio. It was found that increasing the thickness of steel tubes and wall faceplates as well as wall width can effectively increase the lateral performance of the structure but increasing the steel beam stiffness only results in limited improvement. Increasing the steel grade can improve the lateral performance of the structure much more significantly than the concrete grade. When the axial load ratio reaches 0.6, the lateral strength of the structure is greatly reduced owing to the P-Δ effect. Moreover, one multi-storey bare frame structure and three multi-storey coupled SCC wall-frame structures were constructed in OpenSees as a case study. The multi-storey coupled SCC wall-frame structures display extraordinary lateral load-carrying capacity by analysing the curves of base shear force versus roof drift ratio. Besides that, instead of the nominal inter-storey drift ratio, the destructive inter-storey drift ratio together with the roof drift ratio are recommended to assess the multi-storey coupled SCC wall-frame structures in order to avoid overconservative design.

Issues Regarding the Appropriateness of Using Precast Reinforced Concrete Frame Structures Compared to Monolithic Reinforced Concrete Frame Structures, in Office Buildings and Residential Buildings

Abstract Given the current context at national and European level in terms of reducing skilled labour force in constructions, as well as the high level of density and traffic in large cities, there is an increasing emphasis on the possibility of shortening the duration of building the structural frames on site, reducing the number of workers or even reducing the level of noise pollution. Thus, the introduction of precast technologies in the case of office buildings and residential buildings, with multi-storey frame structure, is becoming an increasingly pressing and topical issue. The purpose of this paper is to enable structural engineers, architects and potential investors to consciously choose the type of optimal structure, taking into account a number of technical and economic aspects. In this sense, in order to highlight the main advantages and disadvantages of using multi-storey precast reinforced concrete frame structures, a comparative case study will be carried out between a precast frame structure and a monolithic frame structure, respectively.

Collapse resistance of multi-storey steel frame structures: Evaluation method based on member resistance

As the interaction of structural members and the type of beam-to-column connections significantly influence the collapse resistance of steel frame structures, there are limitations in using the existing theoretical models to calculate the resistance of multi-story steel frame structures with different structural parameters. The collapse resistance of multi-storey frame structures can be calculated using member resistance based on determining the inter-story constraints and the law of mutual influence of inter-story internal forces. In this paper, the resistance of structural members during the small and large deformation stage is discussed based on the coupling relationship between the bending moment and axial force developed in members. The theoretical analysis showed that the evolution of internal force multi-storey frames was reflected in the inter-story differences of flexural resistance and axial forces in the small and large deformation stages, respectively. Thus, a resistance calculation method suitable for steel frame structures with different connections was proposed based on member resistance. Finally, the rationality of the theoretical method was verified through a multi-scale model. The theoretical calculations showed a significant agreement with the numerical results.

Design of vertical members in large-span steel structures: Can relevance of seismic actions be exceeded on account of indirect fire actions?

Effect of lateral actions evolving from restrained thermal expansions of horizontal structural elements (beams, slabs) on stability of vertical elements (columns, walls) of fire-engulfed buildings remains unaddressed sometimes in engineering practice. Discussion with engineers has revealed that two reasons may contribute most to such design inconsistency. The first is premature assumptions that the effects of these actions can not be sufficient to exceed the effects of other lateral design actions, especially if for the same building considerable seismic influences are also expected. The second reason is the fact that, according to the present version of Eurocodes, these actions need not be addressed specifically if the design is carried out under standard fire curve. This curve, however, is still applied often in practice. For certain vertical members, such as the ones positioned somewhere within the middle of fire compartments, indirect lateral fire actions may indeed be negligible, e.g., due to partial or complete balancation of these actions in fire evolving simultaneously at two opposite sides. However, more pronounced effect might be observed for vertical members at the boundary between a fire-engulfed and a neighbouring cold-side compartment, especially in steel or RC buildings with larger horizontal spans prone to striking lateral thermal elongations. While such structures represent a fair share of existing building stock (they are common, e.g., in prefabricated industrial and commercial buildings), this problem deserves a special attention. In this paper two real one-storey large-span halls are analysed for confirmation of the above hypothesis. Each of them comprises two structurally connected units, i.e. one RC- and the other steel-framed, where fire is assumed to engulf the steel-framed unit. Stability of the ’cold-side’ RC columns at the boundary between both sectors is discussed and for the latter indirect fire actions from the connecting fire-engulfed steel members are found to be of a comparable or a greater size to effect of moderate-size seismic actions. The greatest effects of the observed fire actions are found at average steel temperatures below 400 °C. This is a rather low temperature expected to be achieved (sooner or later) in most fire-affected steel elements with or without fire protection. At the same time, as in this paper also proven by results of exact visco-plastic structural computations, this is also a temperature at which no pronounced creep strains yet evolve in steel within time frames relevant for common structural fire analyses. In addition, the paper also shows that these conclusions would not change for other variations of the discussed two buildings where other possible kinematic boundary conditions were applied at the ends of the steel members or other possible thermal boundary conditions were assumed along their longitudinal surfaces. At most, the observed indirect fire effects would only increase further in these cases. Thus, at least for structures of a similar type (i.e. one-storey frame structures of horizontal spans of similar size and materials), the authors propose that the discussed lateral indirect fire actions are not dismissed from any design procedure regardless of the expected fire scenario as long as steel is allowed to heat to moderate temperatures (around 400 °C). In the last part of the paper the authors also discuss possible change of these findings for multi-storey frame structures and/or frame structures of other spans. However, for these (and other possible) structural types, a more detailed further investigation is proposed.

Seismic performance of an industrial multi-storey frame structure with process equipment subjected to shake table testing

Past earthquakes demonstrated the high vulnerability of industrial facilities equipped with complex process technologies leading to serious damage of process equipment and multiple and simultaneous release of hazardous substances. Nonetheless, current standards for seismic design of industrial facilities are considered inadequate to guarantee proper safety conditions against exceptional events entailing loss of containment and related consequences. On these premises, the SPIF project -Seismic Performance of Multi-Component Systems in Special Risk Industrial Facilities- was proposed within the framework of the European H2020 SERA funding scheme. In detail, the objective of the SPIF project is the investigation of the seismic behaviour of a representative industrial multi-storey frame structure equipped with complex process components by means of shaking table tests. Along this main vein and in a performance-based design perspective, the issues investigated in depth are the interaction between a primary moment resisting frame (MRF) steel structure and secondary process components that influence the performance of the whole system; and a proper check of floor spectra predictions. The evaluation of experimental data clearly shows a favourable performance of the MRF structure, some weaknesses of local details due to the interaction between floor crossbeams and process components and, finally, the overconservatism of current design standards w.r.t. floor spectra predictions.

Structural Health Monitoring of Multi-Storey Frame Structures using Piezoelectric Incompatibility Filters: Theory and Numerical Verification

In the present paper, we develop a novel method for structural health monitoring of multi-storey frame structures with the capability to detect and localise local damage. The method uses so-called spatial incompatibility filters, which are continuously distributed strain-type sensors only sensitive to incompatibilities. In the first part of the paper the concept of incompatibility filters is introduced for multi-storey frame structures and it is shown how these filters can be used to detect and localise local cracks in frame structures. In the second part of the paper we study the use of incompatibility filters put into practice by piezoelectric sensor networks for structural health monitoring of a three-storey frame structure. The design of the piezoelectric sensor network is based on an analytical analysis of the frame structure within the framework of the method developed in the first part of the paper and a numerical verification using three-dimensional Finite Elements completes the paper

Seismic Performance of Steel Concrete Composite Multi-Storey Frame

To investigate seismic behaviour of steel concrete composite multi-storey frame structures, based on researches of composite frame, a concrete encasement rectangular is suggested for the beam and filled steel tube for column. The preliminary demonstrate the excellent performance of the element, and reaffirm the applicability of composite beam-columns to the earthquake-resistant design of multi-storey structures. Then the mode analysis, the response spectrum and time history analysis under rare earthquakes are carried out. Result of ongoing experimental and numerical investigations are shown.

Effects of the crack location on the dynamic response of multi-storey frame subjected to the passage of a high-speed train

The high-speed railways require more viaduct than a conventional railway. When the viaduct is subjected to high-amplitude vibrations for a long time, the fatigue-induced crack formation can occur . The presence of a crack changes the stiffness of the structure. Depending on the location of the crack, the reduction effect in stiffness varies. In this study, the presence of a single crack in a multi-storey frame structure, which is considered as a viaduct model, has been investigated. Effects of crack location on the dynamic response are investigated via 3D velocity-crack location-dynamic magnification factor (or maximum displacement) graphs. The train is modelled as a four-axle two-bogie multi-body system with 10 DOF and moving at a constant speed. The finite element method, based on Euler–Bernoulli beam theory, is used to simulate the vibrations of the coupled vehicle-structure system. Wilson-theta time integration scheme is used to solve the equation of motion. It has been determined that when the crack is located at the midpoint of the top beam, the highest effect on the dynamic response is observed.

A simplified approach for collapse assessment of multi-Storey steel framed-structures with one column loss

This paper provides a design-based framework in collapse assessment of multi-storey steel framed-structures. A simple approach for different column-removal scenarios of the structure is proposed, wherein the three-dimensional effects of the floor system, boundary restraints of the affected substructure and potential vierendeel actions in multi-storey framed-structures are incorporated. The effectiveness of the approach proposed is verified against numerical analyses on a full-scale steel frame with six-storey. Extensive discussions are also made from the comparisons between the results from the simplified approach and numerical simulations with finite element method (FEM). The proposed approach is found to sometimes give conservative evaluations for the column destabilizing-induced collapse of the structure, which ensures sufficient security in the robustness assessment of the structure. For the beam/connection failure-induced collapse, the proposed approach can obtain more reliable assessment conclusions.

Study on Damage Law of Multistory and High-rise Steel Frame Structures under Strong Earthquake

In order to study the seismic performance of steel frame structures of multistory and high-rise buildings under strong earthquake, six and nine story steel frame structure models are established. In this paper, based on the peak acceleration of frequent earthquakes with 8 degree (0.2g) seismic effect and the finite element calculation of artificial seismic wave, the damage law of multi-storey and high-rise steel frame structures is studied under strong earthquakes, such as Taiwan CHICHI earthquake and the MENDOCINO earthquake in the United States. The results suggest that: under the strong earthquake, the inter-storey drift angle is obviously concentrated when the cross-section size of column and beam changes, so that the rational control of the inter-storey drift angle is conducive to reducing the concentration of structural damage.

Evaluation of eddy current damper for vibration control of a frame structure

In this study, an eddy current damper (ECD) prototype model is presented. The ECD consists of three principal components: Neodymium Iron Boron (NdFeB) permanent magnets, a copper plate (conductive material) and an aluminium frame. The magnets have a rectangular design, and can be assembled with magnetic pole projection in either alternative or unidirectional orientations and in two orthogonal directions. The key merit of this type of ECD is its non-contact characteristic; thus there is a complete absence of mechanical friction. This study examines the use of this prototype damper when applied to suppress structural vibration in multi-storey frame structure. To effectively estimate the damping performance of the ECD, simple analytical calculations involving both infinite and finite boundaries are proposed and illustrated in this paper. These can be compared against the results of more sophisticated finite element analysis (FEA). The conductive material can be defined to move in two orthogonal directions. Therefore, based on the four magnet configurations and two directions of motion of conductive material, a total of eight models were created for analysis and validated by the proposed designed formule. It was found that analysis based on the method of images provides a satisfactory estimation of the damping force, similar to that estimated using the FE model. This study also includes experimental testing of a prototype ECD applied to suppress vibration within a six-storey aluminium frame structure. This testing shows that the prototype ECD is able to provide a significant level of damping with performance comparable to that of an ideal conventional linear viscous damper.

SEISMIC DESIGN OF FRAME STRUCTURES EQUIPPED WITH INNOVATIVE HYSTERETIC DISSIPATIVE DEVICES

In the present work, a Performance-Based Seismic Design procedure applied to multi-storey frame structures with innovative hysteretic diagonal steel devices (called Crescent Shaped Braces or CSB) is introduced. CSBs are steel elements of peculiar geometrical shapes that can be adopted in frame buildings as enhanced hysteretic diagonal braces. Based on their "boomerang" configuration and placement inside the frame structure, they are characterized by a lateral stiffness uncoupled from the yield strength and, if properly inserted, by an overall symmetric hysteretic behavior with hardening response at large drifts, thus preventing from global structural instability due to second-order effects. The procedure here presented is intended to guide the structural engineer through all the steps of the design process, from the selection of the performance objectives to the preliminary sizing of the CSB devices, up to the final design configuration. The steps are described in detail through the development of an applicative example.

Role of masonry infill wall on the seismic behavior of typical four-storey building in Pakistan

Masonry infill walls are used as partition in reinforced concrete frames and are considered as a non-engineering structure for design and analysis purposes. The goal of this study is to compare different response parameters such as displacement, storey drift, base shear and ground overturning moment of a multi-storey RC frame structure with and without infill walls. For this purpose, a four-storey building is selected, which is supposed to be situated on stiff soil type (SD) and seismic zone 2B according to the Building Codes of Pakistan. Openings are neglected in the building. Non-linear static pushover analysis method is used to check the behavior of building during earthquake using SAP-2000. To find the width of compression struts, FEMA-356 is used. The results are compared and shown in the form of graphs. It is concluded that the masonry infill walls may have significant effects on the seismic response of the reinforced concrete frame structures, therefore, infill walls need to be considered during the design and analysis of the building.

Experimental and numerical investigation of the static performance of innovative prefabricated high-strength composite columns

An innovative high-performance precast beam-to-column joint for multi-storey framed structures is introduced. The proposed solution consists of coupling between Composite Steel Truss Concrete (CSTC) beams with a concrete base and High-Strength Concrete (HSC) columns. This paper focuses mainly on the static performance of prefabricated HSC columns, including experimental and numerical investigations. The finite element model of the structural system is calibrated on experimental static testing evidence. On the basis of the data collected, the finite element model is used to evaluate the strength domain of members and optimize the related coupling system between columns. Aiming to limit time-consuming analyses and provide practical rules for design, an analytical simplified procedure is introduced to compute the assembly’s strength domain. An analytical approach is adopted to estimate the reference design strength for the considered composite columns, accounting for the partial safety factor imposed by codes and allowing for estimation of the limit on the number of storeys for frames adopting the proposed precast technology.

The effect of multiple tuned mass dampers on response control of base isolated multi-storey space frame structure

The effect of multiple tuned mass dampers on response control of base isolated multi-storey space frame structure

The effect of multiple tuned mass dampers on response control of base isolated multi-storey space frame structure

Dynamic response of base isolated multi-storey symmetrical and asymmetrical space frame structures with multiple tuned mass dampers (MTMD), subjected to bi-directional harmonic and Mexico earthquake ground motions are studied. A four-storey space frame structure having six degrees of freedom (three translations along x, y, z-axes and three rotations about these axes) at each node is considered for study. Each tuned mass damper (TMD) is modelled using a two-noded element having two translational degrees of freedom at each node. MTMD with uniformly distributed frequencies are considered for this purpose. The effectiveness of MTMD in suppressing the structural response is determined by comparing the response of corresponding structure without MTMD. It is found that the MTMD can be used effectively to suppress the responses of the symmetrical and asymmetrical base isolated space frame structures. The effect of important parameters on the effectiveness of the MTMD is also studied. The parameters include the fundamental characteristics of the MTMD such as damping, total number of MTMD, tuning frequency ratio and frequency spacing of the dampers. It is shown that these parameters have considerable influence on the effectiveness of the MTMD in reducing the dynamic response of the base isolated structure.

A direct design procedure for frame structures with added viscous dampers for the mitigation of earthquake-induced vibrations

A direct procedure for the seismic design of building structures with added viscous dampers is described in this paper. The procedure is applicable to regular multi-storey frame structures which are characterized by a period of vibration lower than 1.5 s. It aims at providing practical tools for the direct identification of the mechanical characteristics of the manufactured viscous dampers as well as for the structural design of the frame members’ so that a target level of performance is achieved. The design philosophy is to limit the structural damages under severe earthquakes. First, a target damping reduction factor is selected to achieve the desired reduction in the peak structural response. The linear damping coefficients of the equivalent linear viscous dampers are calculated taking advantage of modal damping ratios properties of classically damped systems. Then, simple analytical formulas for the estimation of peak inter-storey velocities are used, together with an energy criterion to identify the non-linear mechanical characteristics of the manufactured viscous dampers. Finally, the internal actions in the structural elements are estimated through the envelope of two equivalent static analyses (ESA), namely: ESA1 in which the naked structure is subjected to a first set of equivalent lateral forces, and ESA2 in which the structure, with rigid diagonal braces substituting the added viscous dampers, is subjected to a second set of equivalent lateral forces. At this preliminary stage of the research, the procedure is targeted for the preliminary design phase, since correction factors to improve the accuracy in the estimation of the peak inter-storey velocities needs to be calibrate. Therefore, for final design, non-linear dynamic analyses are recommended.