Analysis of the structural performance of the Cakung house in East Jakarta aims to determine the behavior and performance of the building by using the Special Moment Bearing Frame system (SRPMK). ...Evaluation is carried out on the performance of the building structure by using a structural analysis aid program. And the lateral force capacity that the system can withstand is 1592432.05 Kgf in the X direction and 643948.61 Kgf in the Y direction. Where the pushover analysis using the ATC 40 method, the melting point occurred for the first time at a displacement of 23.57 cm in the X direction and 7.28 cm in the Y direction. And serious damage occurred at the displacement of 77.49 cm in the X direction and 94.84 in the Y direction. The analysis found that the drift ratio value of the maximum total deviation and the maximum inelastic deviation that occurs in the structure is less than 1%. So that the level of performance of the design is in the category of Immediate Occupancy (IO).
Kilometer-span cable-stayed bridges usually adopt tall inverted Y-shaped pylons. Such pylons may behave inelastically under strong transverse seismic excitations. Therefore, efficient analysis ...methods (e.g., pushover analysis) for transverse elastoplastic behavior assessments of inverted Y-shaped pylons are of great interest for academic and industrial communities. Based on equal displacement rule, this study proposes an applied deformation-based pushover analysis (DPA) incorporating a novel multi-node load pattern for the efficient transverse seismic behavior assessments of inverted Y-shaped pylons in kilometer-span cable-stayed bridges. A case study of the inverted Y-shaped pylon of Sutong Bridge is adopted to demonstrate the proposed DPA. The proposed multi-node load pattern for DPA is verified through the validation of the loaded-node selection and equal displacement rule for the studied pylon. The ability of DPA in seismic behavior assessments is then systematically validated by comparative studies with incremental dynamic analysis (IDA), conventional pushover analysis (CPA), and modal pushover analysis (MPA) in terms of displacement, bending moment and curvature responses of pylon as well as computational costs.
•A novel deformation-based pushover analysis (DPA) is proposed for tall inverted Y-shaped bridge pylons.•A multi-node load pattern is proposed for the DPA method to avoid premature local failure.•The equal displacement rule is validated for tall bridge pylons.•DPA can be employed for transverse seismic behavior evaluation of inverted Y-shaped pylons.
For structural engineers, existing surrogate models of buildings present challenges due to inadequate datasets, exclusion of significant input variables impacting nonlinear building response, and ...failure to consider uncertainties associated with input parameters. Moreover, there are no surrogate models for the prediction of both pushover and nonlinear time history analysis (NLTHA) outputs. To overcome these challenges, the present study proposes a novel framework for surrogate modelling of steel structures, considering crucial structural factors impacting engineering demand parameters (EDPs). The first phase involves the development of a process by which 30,000 random steel special moment resisting frames (SMRFs) for low to high-rise buildings are generated, considering the material and geometrical uncertainties embedded in the design of structures. In the second phase, a surrogate model is developed to predict the seismic EDPs of SMRFs when exposed to various earthquake levels. This is accomplished by leveraging the results obtained from phase one. Moreover, separate surrogate models are developed for the prediction of SMRFs’ essential pushover parameters. Various machine learning (ML) methods are examined, and the outcomes are presented as user-friendly GUI tools. The findings highlighted the substantial influence of pushover parameters as well as beams and columns’ plastic hinges properties on the prediction of NLTHA, factors that have been overlooked in prior studies. Moreover, CatBoost has been acknowledged as the superior ML technique for predicting both pushover and NLTHA parameters for all buildings. This framework offers engineers the ability to estimate building responses without the necessity of conducting NLTHA, pushover, or even modal analysis which is computationally intensive.
•Generated 30,000 random steel buildings for surrogate model development.•Established novel design of experiment framework for surrogate modelling.•Used material, geometry, seismic, and pushover factors for surrogate development.•Developed GUIs for pushover and time history analysis prediction.•Used 13 ML methods for building response prediction with advanced feature selection.
Electricity transmission system is well recognized as a lifeline system in the modern society, and its failures in past major earthquakes have aroused the concern about its seismic vulnerability. In ...the present study, fragility curves are developed to assess the vulnerability of a typical transmission tower subjected to near-field ground motions. A probabilistic seismic demand model (PSDM) is constructed for the transmission tower in terms of the maximum inter-segment drift ratio (ISDR) and the spectral acceleration (Sa) at the fundamental period of the structure. Pushover analysis is performed to define the capacity limit states for the transmission tower, which are serviceability, damage control and collapse prevention in this research. The data for the PSDM are acquired by using incremental dynamic analyses (IDAs) of a suite of seismic records. Additionally, the influence of the seismic incident angles and the coupling effect between the transmission tower and lines on the structural fragility are further investigated. The results quantify the seismic vulnerability of the transmission tower and demonstrate the influence of the seismic incident angles and the dynamic coupling effect between the transmission tower and lines.
•A new probabilistic seismic demand model is constructed for the transmission tower•Fragility curves are developed for the transmission tower subjected to near-field ground motions•Influence of the seismic incident angles and the dynamic coupling effect on the structural fragility are investigated.
•Energy efficiency of RH structures reaches a higher peak under inclined loads.•Energy efficiency of RH structures is high at the early stages of uniform compression.•Significant reduction in mean ...crushing force is observed for RH structures at inclined loads.•A new transition stage is induced under inclined loads.•New micro modes (‘distorted X’, and ‘>’ modes) for RH structures emerge under inclined loads.
The present study unravels the deformation mechanisms observed during the static inclined compression of re-entrant honeycomb (RH) auxetic structure. A pushover Riks analysis is conducted by facing a rigid plate towards the structure at various angles. A new ‘plastic hinge tracing method’ is introduced to systematically extract the micro deformation mechanisms under inclined loading. The identified modes are related to the macro deformation regime and the overall mechanical response of the RH structure. Moreover, their relation to various measures of efficiency is elaborated. It is shown that a transition stage emerges under inclined loading, which delays achieving the peak energy efficiency. The overall energy dissipation decreases in the inclined cases but interestingly, the performance of the RH structure does not deteriorate. Namely by maintaining a low crushing force under inclined loads, the trade-off of low energy dissipation is balanced and a lower impact is anticipated. Finally, the similarities between the transition stage and the macro modes are highlighted and further directions for investigation are proposed.
In this research, the seismic behavior of single-layer diamatic dome (SLDD) structures was analyzed under earthquake loads, and then the seismic response modification factors (SRMFs) of these ...structures were extracted. For this purpose, 16 models with different span lengths (SLs) and rise-to-span ratios (RSRs) were designed, and the effects of SL and RSR on the SRMFs of these structures were evaluated. Also, the effect of member density on the SRMFs was studied. The models were first designed under the applied loads based on relevant design codes. Then, by performing the nonlinear time history analyses using the three translational components of ground motion records, the control point and target displacement in the horizontal and vertical directions were obtained to implement the pushover analyses. Thereafter, the pushover analyses were implemented by using the target displacements derived from the nonlinear time history analyses, and the SRMFs of SLDD structures in both horizontal and vertical directions were obtained. The results indicate that models with RSRs of 1/7 to 1/3 remained in the elastic range in the horizontal direction. For the models with an RSR greater than 1/3, if the RSR increases, the ductility and behavior factor increases in the horizontal direction. However, there is a downward trend in the vertical direction due to the increase in the vertical stiffness. The horizontal and vertical behavior factor was obtained in the range of 1.155–2.459 and 1.155–2.893, respectively. Finally, by using the results obtained and through the nonlinear regression analysis, equations were proposed for the period, target displacement, displacement amplification factor, and behavior factor for SLDD structures in terms of the SL and RSR in the horizontal and vertical directions.
•The seismic response modification factors (SRMFs) of single-layer diamatic dome structures are extracted.•The effect of member density on the SRMFs is studied.•Equations were proposed for the period, target displacement, behavior factor, and displacement amplification factor.•The SRMFs of these structures are obtained in both horizontal and vertical directions.
•Nonlinear static analyses for the seismic assessment of masonry buildings.•Seismic assessment of existing complex masonry buildings with flexible floors.•Vulnerability assessment of mixed ...masonry–reinforced concrete buildings.•Reliable models and strength criteria for masonry pier and spandrel elements.•An advanced modelling tool useful both at research level and engineering practice.
The seismic analysis of masonry buildings requires reliable nonlinear models as effective tools for both design of new buildings and assessment and retrofitting of existing ones. Performance based assessment is now mainly oriented to the use of nonlinear analysis methods, thus their capability to simulate the nonlinear response is crucial, in particular in case of masonry buildings. Among the different modelling strategies proposed in literature, the equivalent frame approach seems particularly attractive since it allows the analysis of complete 3D buildings with a reasonable computational effort, suitable also for practice engineering aims. Moreover, it is also expressly recommended in several national and international codes. Within this context, the paper presents the solutions adopted for the implementation of the equivalent frame model in the TREMURI program for the nonlinear seismic analysis of masonry buildings.
