•Forty-two typical and practical applications of UHPC in bridges are introduced.•The shortcomings which constrain the application of UHPC are summarized.•Potential usages of UHPC for seismic ...resistance and anti-explosion are predicted.•Further researches of UHPC in bridge engineering are proposed.
Ultra high performance concrete (UHPC) is a type of cement-based composite, which is the most innovative product in concrete technology during the last 30 years. The advantages of UHPC compared with the common concrete, such as superior mechanical performance, excellent anti-seismic property and resistance against environmental degradation are introduced in the paper. The paper begins by briefly introducing its history of development and technical performance. Then, the research and application situation of UHPC in bridge engineering are discussed and many practical applications in bridge bearing component, bridge deck pavement and bridge joints are summarized. Moreover, the paper analyzes advantages and shortcomings of UHPC and the constraints for the application of UHPC in bridge engineering. In addition, the performance of UHPC in seismic resistance and anti-explosion is briefly summarized. Based on these works, prediction of UHPC further research in the future is prospected.
•Dual frames with removable links provide a structure with re-centring capability.•The re-centring capability was validated through a full-scale experimental programme.•Good re-centring of frame with ...links not connected to the slab was observed.•The links can be removed by unbolting if permanent deformation after earthquake is small.•Flame cutting of links is recommended if larger permanent drifts occur.
Modern seismic codes allow for inelastic deformation in dissipative zones during design earthquakes, accepting damage to the relevant structural parts to a certain extent. Experience has shown that repair work is needed after moderate to strong earthquakes. The use of structural systems that are easily repairable is therefore beneficial in seismic regions. For a structure to be repairable, in addition to constraining any inelastic deformation to removable dissipative members, any permanent (residual) drift should be eliminated. To realise a re-centring capability in a structure with eccentrically braced frames (EBFs) and removable dissipative members, a dual structural configuration is used, which combines EBFs and moment-resisting frames (MRFs). If the more flexible MRFs are kept elastic, they would provide the restoring force necessary to re-centre the structure upon the removal of the damaged removable links (the dissipative members). This paper presents an experimental validation of the re-centring capability of a dual eccentrically braced frame with replaceable links, based on a full-scale experimental testing programme, performed at the European Laboratory for Structural Assessment (ELSA) at the Joint Research Centre (JRC) in Ispra within the framework of the Transnational Access of the SERIES Project. The experimental set-up, programme, and instrumentation are described. The results attained through the re-centring of the structure are presented, as well as its overall seismic performance and information on the interaction between the steel frame and the reinforced concrete slab in the link region.
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•A novel buckling-controlled brace inspired by origami (O-BCB) is proposed.•A hierarchical design strategy from rigid to non-rigid origami patterns is adopted.•Gradient design schemes ...had a positive impact on the uniformity of deformation.•Non-rigid origami patterns enhance both bearing and energy dissipation capacities.
Equipping energy dissipation devices in the structures is one of the effective methods to resist earthquake disasters. Here, a novel buckling-controlled brace inspired by origami (O-BCB) was proposed as anti-seismic technology for protecting engineering structures. A hierarchical design and analysis strategy was adopted for various types of origami patterns. An O-BCB based on Tachi origami pattern was manufactured, tested, and analyzed to verify the hysteretic performance under cyclic reversed loading. Considering the non-uniform distribution of deformation and stress in the Tachi patterned brace, two gradient design schemes in the lengthwise direction were proposed. To balance the bearing capacity and energy-dissipating capabilities of O-BCBs, the implementation of non-rigid origami patterns including pyramid, crash-box, and triangular patterns were analyzed. Results show that O-BCBs could provide valuable options for the development of earthquake-resistant technologies in the field of civil engineering.
The seismic resistance of nuclear power plant equipment and piping is determined, inter alia, by the seismic resistance of their steel supporting structures. During the operation of the nuclear power ...plant power unit, mechanical loads from the elements installed on them are transferred to the steel supporting structures of the equipment and piping. During an earthquake, seismic loads are added to these loads. By state building codes, when considering steel structures in special operating conditions (in particular, exposed to seismic hazards), it is necessary to comply with additional requirements that reflect the features of these structures. Given this, the issue of developing approaches to the compilation of load combinations in assessing the seismic resistance of steel supporting structures of nuclear power plants equipment and piping is acute, taking into account the specific conditions of their operation. The paper is also relevant as it is one of the priority areas of science and technology under the legislation of Ukraine. The development of approaches to the compilation of the calculated load combinations will contribute to the improvement and development of methods for assessing the safety of nuclear power facilities. The paper presents the results of the review of the provisions of state building codes on the calculated combinations of loads when assessing the strength of steel structures. Approaches to the compilation of the calculated load combinations in assessing seismic resistance of steel supporting structures power units of nuclear power plants equipment and piping taking into account the specific conditions of their operation have been developed.
Elaboration analytical and computer modeling, changing dynamic parameters of short-term and long-term loaded nonlinearly deformable large-span spatial shell structures are investigated in this ...research paper. The proposed physical and geometrically nonlinear models of deformation and computational algorithms for solving dynamic problems are applied to assess the stress-strain state of smooth and ribbed spatial systems with variable stiffness caused by the accumulation of damage and the orthotropic structure reinforced by the ribs of the structures of the studied systems. The possibility of using the proposed method of accounting for variable dynamic stiffnesses in calculations for solving problems of dynamic strength and stability of spatial large-span shells of complex geometry is shown.
•Progressive collapse capacity and earthquake resistance of a RC frame structure.•Multi-hazard structural analysis based on nonlinear incremental static procedures.•Significant impact of brittle ...shear failures of beams and columns.•Seismic retrofitting based on local shear strengthening with CFRP systems.•Effectiveness of seismic retrofitting on robustness enhancement.
Most of the existing buildings in seismic prone regions have been built before the publication of modern design provisions against earthquakes, resulting in the need for structural retrofitting. Furthermore, some of those buildings are also subjected to additional hazards that may be either triggered by earthquakes (e.g., landslides, soil liquefaction, tsunamis) or associated with other natural or anthropogenic events, such as floods, vehicle collision, blast, and fire. A multi-hazard performance assessment of building structures is thus of paramount importance to implement integrated retrofit strategies, which otherwise would not be economically sustainable if oriented to structural risk mitigation against a single hazard. While retrofit strategies to improve the seismic performance of reinforced concrete (RC) structures have been widely investigated, structural retrofitting against progressive collapse has received very little attention. Within this context, the present paper illustrates a numerical investigation on the influence of seismic retrofitting on structural robustness of a four-storey, five-bay, RC frame building designed only to gravity loads. Seismic performance and structural robustness were respectively evaluated in OpenSees through pushover and pushdown analyses of a fibre-based finite element model. Structural robustness was evaluated under two relevant column-removal scenarios, i.e., the sudden loss of a central and a corner column, whereas earthquake resistance was assessed according to the N2 method, evidencing the need for seismic retrofitting. A retrofit measure based on carbon fibre reinforced polymers was then considered to avoid premature brittle failures. Analysis results show that this retrofit strategy was able to increase both seismic safety and structural robustness. Subsequently, a parametric analysis was carried out in order to evaluate the impact of beam span length and shear strength of the retrofitting system.
A novel variable hysteresis performance damper (VHD)—multi-stage slip friction damper is developed and applied to implement multi-level seismic resistance of structures. Different from the ...conventional slip friction dampers, which feature only a single type of slip friction surface, this innovative damper incorporates two types: a flat slip surface and a wedge slip surface. The quasi-static cyclic loading tests of the VHD were carried out to investigate its variable hysteresis performance. The test results revealed that the developed damper presented excellent adaptive performance, and its hysteresis behavior changed from a complete rectangle with efficient energy dissipation to a flag-shaped curve with exceptional self-centering capacity as deformation increases. Subsequently, the developed VHD with unique adaptive performance was applied in RC bridge piers (BP) to improve the seismic performance. Nonlinear time history and fragility analysis methods were employed to assess the seismic performance of the RC bridge piers with VHDs (BP-VHD) in deterministic and probabilistic manners, considering maximum and residual deformations as performance indicators. For comparison, seismic responses of RC bridge piers with traditional buckling restrained braces (BRBs) and self-centering energy dissipation braces (SCEBs) were also presented. The analysis and comparison results demonstrate that the developed VHD is as effective as BRB in reducing maximum deformation at small PGAs, meanwhile, it can effectively reduce the residual deformation of the structure to allowable values when the PGA is large. Furthermore, the failure probability of BP-VHDs is lower compared to piers with BRBs and SCEBs, particularly concerning maximum and residual drift ratios as performance indicators. The application of the VHD can effectively achieve the goal of multi-level seismic resistance for RC bridge piers.
•A novel variable hysteresis performance damper (VHD)—multi-stage slip friction damper was developed to implement multi-level seismic resistance of structures.•Quasi-static cyclic loading tests showed that the VHD presented variable hysteresis behavior with excellent adaptive performance.•The nonlinear time history and fragility analysis results showed that the application of the VHD can effectively achieve the goal of multi-level seismic resistance for RC bridge piers.
•Ultimate load of specimens incorporating ECC was greatly enhanced.•ECC imparted to the specimens greater ability to resist reverse cyclic loading steps.•ECC specimens exhibited higher energy ...absorption capacity compared to the control.•ECC specimens showed ductile failure mode triggered by plastic hinging in the beams.•ECC specimens showed reasonable safety against shear stress-induced joint failure.
This study aims to evaluate the feasibility of using ultra-ductile Engineered Cementitous Composites (ECC) as a means to enhance the performance of beam–column connections. Nine one-third scale specimens, consisting of type 2 (ACI352R-02) interior connections at a zone of high seismicity (UBC-zone 3), were tested under reverse cyclic loading, simulating seismic excitation. The joints of these specimens were typical in geometry and main reinforcement detailing to specimens of a prototype building frame designed according to ACI318-08. The primary variables were the amount and arrangement of transverse reinforcements, and the materials within the plastic zone of the connection.
The performances of a series of ECC-enhanced beam–column interior connections were compared to that of a control concrete counterpart to evaluate the benefits of using ECC in this type of application. The column load–displacement response (including the ultimate load and ultimate displacement), the (hysteresis) energy absorption capacity, and the cracking response were used as criteria in the comparison.
The test results indicated that the use of ECC material in the connection plastic zone as a replacement of concrete and partial replacement of transverse (confinement) reinforcement can significantly enhance the joint shear resistance, energy absorption capacity, and cracking response, thereby, enhancing the joint seismic resistance and reducing reinforcement congestion and construction complexity.
Introduction: Part of the territory of Russia is located in a seismically dangerous area. In recent years, glued laminated wood has been gaining popularity in private housing construction as well as ...other construction sectors. However, Russian standards lack design and structural requirements for buildings and structures made of glued laminated wood. Methods: The paper reviews the foreign experience in construction with the use of glued laminated wood and presents seismic design for a multi-story building made of wood and materials based on it. Results: We considered the seismic design of a multi-story timber building and reviewed foreign experience in the construction of buildings made of glued laminated wood. Besides, we analyzed how the choice of the material for individual load-bearing structures affects seismic resistance.
Even though tightened building energy efficiency standards are implemented periodically in many countries, existing buildings continually consume a momentous quota of the total primary energy. Energy ...efficiency solutions range from material components to bulk systems. A technique of building construction, referred to as prefabricated architecture (prefab), is increasing in reputation. Prefab encompasses the offsite fabrication of building components to a greater degree of finish as bulk building structures and systems, and their assembly on-site. In this context, prefab improves the speed of construction, quality of architecture, efficiency of materials, and worker safety, while limiting environmental impacts of construction, as compared to conventional site-built construction practices. Quite recently, a 57 story skyscraper was built in 19 days using prefabricated modules. From the building physics point of view, the bulk systems and tighter integration method of prefab minimizes thermal bridges. This study seeks to clearly characterize the levels of prefab and to investigate the performance of modular prefab; considering acoustic constrain, seismic resistance, thermal behavior, energy consumption, and life cycle analysis of existing prefab cases and, thus, provides a dynamic case study-based review. Generally, prefab can be categorized into components, panels (2D), modules (3D), hybrids, and unitized whole buildings. On average, greenhouse gas emissions from conventional construction were higher than for modular construction, not discounting some individual discrepancies. Few studies have focused on monitored data on prefab and occupants’ comfort but additional studies are required to understand the public’s perception of the technology. The scope of the work examined will be of interest to building engineers, manufacturers, and energy experts, as well as serve as a foundational reference for future study.
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