Design Earthquake Research Articles

Review and comparison of different strategies to define earthquake design accelerations

AbstractIn the task of defining earthquake design accelerations, different approaches have been used worldwide and recent advances have led to changes in the rationale behind the choice of these coefficients. Considering that the two main objectives of earthquake engineering are to guarantee a certain level of earthquake safety while allowing designs to be feasible from an economic perspective, given the scarcity of resources, this paper reviews and compares different approaches that have been used to define the earthquake design coefficient, starting from the classic one, based on the selection of a fixed return period, and covering other more complex proposals that include, in one way or another, the physical vulnerability of the buildings. For each case, we assess how these two earthquake engineering objectives are addressed and review, from the coding perspective, their advantages and limitations. Our findings indicate that only one of these approaches, denoted as optimal design and proposed in 1976 by Rosenblueth, explicitly accounts for both earthquake safety and construction costs. We conclude that instead of aiming to have a uniform criterion to define the design accelerations (e.g., uniform return period or uniform collapse probabilities), an optimization criterion must be used, despite the challenges it presents from the perspective of building codes.

Analysis of Internal Forces and Structural Dimensions on the Variations of Courtroom Placement of DPRK Building

The construction of state buildings is caused by the increased mobility of needs. One of them is the DPRK building that wants the placement of the plenary session room to be on the 2nd or 3rd floor. This study aims to evaluate the internal style and behavior of the structure that arises due to variations in the placement of the plenary session room so as to produce the most optimal choice of courtroom for the most effective structural dimensions. Structural analysis was carried out using the ETABS program by carrying out 4 variations of courtroom placement, namely Varian 1 (the courtroom is located on the 1st floor), Varian 2 (2nd floor), Varian 3 (3rd floor), and Varian 4 (4th floor). Variant 2 (DED) is a reference sourced from the DED from the planning consultant. The seismic load analysis used is the method of Dynamic Analysis of Response Spectrum Variety. Parameters reviewed are internal forces (axial, normal, and moment) and structural behavior (story displacement, displacement between floors, nominal base shear forces, and vertical irregularities). The calculation analysis refers to the latest standards, namely SNI 1726:2019, SNI 1727:2020, and SNI 2847:2019. The results of this study indicate that the greatest internal force values occur in Variant 4. The level displacement and the displacement between floors increase in the variant with the smaller structural element dimensions. The level displacement of the X and Y axes has increased in Variant 3 and Variant 4, and has decreased in Variant 1. The nominal base shear force value has decreased for Variants 1, 3, and 4 against Variant 2 (DED) because it has smaller structural dimensions. . All modeling variants experienced soft stiffness irregularity type 1A, excessive soft stiffness irregularity type 1B, and heavy (mass) irregularity type 2. Variant 1 was chosen as the variant with the best courtroom placement, because it met the requirements for earthquake design.

The impact of residual technological stresses on the opening and stability of through cracks in pipeline elements

The impact of residual stresses in a DN850 pipe (steel 10GN2MFA) with austenitic cladding, welding stresses in the mounting annular seam of the pipeline, and residual stresses arising in a curvilinear branch DN350 (steel 08Kh18N10T) during manufacture by plastic deformation on the opening and stability of through cracks is considered. Calculations of residual stresses are performed using the finite element method (FEM). It is shown that residual stresses cause a change in the size and shape of the outflow channel, the coolant flow rate, and the value of the J-integral at the crack tip. In case of short cracks and relatively low operating stresses, the crack edges can close on the inside of the pipe wall due to the action of residual stresses thus leading to a decrease or cessation of the leak. A reversed effect of residual stresses on extended cracks is observed at rather high operating stresses: change in the shape of the outflow channel (an increase in the opening of the crack edges on the outer surface of the pipe) leads to a decrease in the friction of the coolant flow against the crack edges and, hence, to an increase in the leak volume. The results of testing full-scale models of elements of a straight section of the pipeline with a welded seam and a curvilinear branch DN350 with artificially created defects by internal pressure and bending moment are presented. It is shown that local through cracks develop from initial defects, which remain stable at maximum design loads (normal operating conditions plus maximum design earthquake) which matches the calculation results and meets the requirements of the applicability of the concept of «leak before break».

Earthquake Damage Index and Fragility Analysis of Steel Damper for Seismic Isolation Bridge

As an important component in seismic isolation bridges, steel dampers should have excellent low-cycle fatigue performance. This paper performs destructive tests of two types of steel dampers to accurately evaluate the fatigue damage of steel dampers under earthquake action. The damage index of steel dampers under the combined effect of cumulative energy dissipation and maximum deformation is established based on the damage states’ development during the testing process, which can characterize the degree and state of damage of steel dampers under earthquake action. The seismic performance of a seismic isolation continuous girder bridge is evaluated using the frequency statistical method of incremental dynamic analysis beyond the designated functional state, and the fragility analysis of steel dampers was carried out. The results show that the faster the loading rate, the more susceptible steel dampers are to fatigue failure. Under the design earthquake, the basic state of most dampers enters the energy dissipation state, realizing the seismic design goal of protecting bridge piers. The results indicate that the dampers’ overall performance state is slightly damaged, and the fatigue failure of steel dampers is not prominent in most earthquake cases.

ANALISIS STRUKTUR BANGUNAN HOTEL 17 LANTAI DAERAH KEMAYORAN JAKARTA DENGAN PERMODELAN 3D SOFTWARE SAP2000

There are lots of skyscrapers in Indonesia, especially in the Jakarta area. In designing the building, of course, it needs to be designed with appropriate earthquake loads for the location and conditions around the building. Regulations that can be used in the design of skyscrapers are regulations developed by the Indonesian National Standard (SNI), including earthquake loads, gravity loads, and design standards. The method of collecting data in research includes 2 things, namely, (1). primary data, in the form of style output in the SAP2000 version 20 application, Spcolumn v.6.0 column interaction diagrams, and the results of Microsoft Excel calculation analysis. (2) the secondary data obtained is in the form of an image of the structure of the 17 Floor Hotel Kemayoran Area Building.Secondary and primary data processing is in the form of remodeling the redesigned building structure design in SAP2000 version 20 and Spcoloumn v.6.0, determining the seismic design category, analyzing and making changes to the original building structure design that are not in accordance with SNI 1726: 2019 and SNI 2847: 2019. The results of the study found differences in the year versions in SNI 2847:2013 and 2847:2019, SNI 1726:2012 and SNI 1726:2019. In SNI 2847:2019 concerning structural concrete there is a change or addition of special detailing and stirrup reinforcement in columns, beams and floor slabs, while in SNI 1726:2019 concerning earthquake loads there is an increase in seismic forces.

Τhe Behavior of Hybrid Reinforced Concrete-Steel Buildings under Sequential Ground Excitations

In common construction practice, various examples can be found involving a building type consisting of a lower, older, reinforced concrete structure and a more recent upper steel part, forming a so-called “hybrid” building. Conventional seismic design rules give full guidelines for the earthquake design of buildings constructed with the same material throughout. The current seismic codes neglect to provide specific design and detailing guidelines for vertical hybrid buildings and limited existing research is available in the literature, thus leaving a scientific gap that needs to be investigated. In the present work, an effort is made to fill this gap in the knowledge about the behavior of this hybrid building type in sequential earthquakes, which are found in the literature to burden the seismic structural response. Three-dimensional models of hybrid reinforced concrete–steel frames are exposed to sequential ground excitations in horizontal and vertical directions while considering the elastoplastic behavior of these structural elements in the time domain. The lower reinforced concrete parts of the hybrid buildings are detailed here as corresponding to a former structure by a simple approximation. In addition, two boundary connections of the structural steel part upon the r/c part are distinguished for examination in the elastoplastic analyses. Comparisons of the arithmetical analysis results of the hybrid frames for the examined connections are carried out. The seismic response plots of the current non-linear dynamic time-domain analyses of the 3D hybrid frames subjected to sequential ground excitations yield useful conclusions to provide guidelines for a safer seismic design of the hybrid building type, which is not covered by the current codes despite being a common practice.

Analysis and Design of Earthquake Resisting Building with Shear Walls by Using ETAB Software

The present study shows the seismic behaviour of buildings under the action of earthquake load by performing Non-linear Static analysis. Nowadays buildings with shear walls are more popular than buildings without shear walls in earthquake-prone areas due to their resistance during earthquakes. So, this study aims to find the prime location of the shear wall and then investigate the effectiveness of the best shear wall for the RCC structure. In this study, G+13 & G+5 RCC building is considered for the analysis under zone I to zone IV with suitable load combination. The structure is analyzed for earthquakes in the type of structural system using ETABS software. The shear wall starts from the foundation level and should continue throughout the building.

Machine learning based prediction model for plastic hinge length calculation of reinforced concrete structural walls

Reinforced concrete structural walls (RCSWs) are integral part of buildings and other structures and are used to carry in-plane and out-plane loads. For assessment purposes and to ensure safety and resilience of the structure, the curvature, capacity, and strain demands of RCSWs need to be estimated. Nonlinear numerical models are increasingly used in earthquake engineering design and assessment, where it is critical to develop high fidelity simulation tools to precisely forecast the global and local behavior of RCSWs. Plastic deformations concentrated in small regions, i.e. plastic hinges, and characterized through the concept of plastic hinge length (PHL), are conventionally used to define the inelastic response of RCSWs. In this study machine learning (ML) algorithms were leveraged in evaluating the PHL of RCSWs. A database containing 721 planar and nonplanar RCSW samples were utilized for training and testing ML models. Four different algorithms were employed, namely: XGBoost, CatBoost, Random Forest (RF), and genetic programming. The RF model outperformed other ML counterparts. The results of the best ML model were also compared against empirical equations available in literature and nonlinear regression analysis. The proposed ML model provided much better predictions than the existing relationships. Predictions of most empirical models were found to be extremely over (or under) conservative. The proposed ML model was also presented via an online tool where users can obtain the PHL of any RCSW simply by inputting wall parameters and clicking a run button.

Assessment of Structural Systems to Design Earthquake Resistance Buildings by Employing Multi-Attribute Decision-Making Method Based on the Bipolar Complex Fuzzy Dombi Prioritized Aggregation Operators

An earthquake is a natural phenomenon that occurs when two tectonic plates in the earth’s crust move against each other. This movement creates seismic waves that can cause the ground to shake, sometimes resulting in damage to buildings and infrastructure. It is important to be prepared for earthquakes, particularly if you live in an area that is at high risk for seismic activity. This includes having an emergency kit, knowing how to shut off utilities, having a plan in place for what to do in the event of an earthquake, and most importantly, constructing earthquake resistance buildings. The assessment and the ranking of structural systems to design earthquake resistance buildings is a MADM (multi-attribute decision-making) dilemma. Consequently, in this script, we initiate the method of MADM under the bipolar complex fuzzy (BCF) information. For this method, we devise BCF Dombi prioritized averaging (BCFDPA), BCF Dombi prioritized weighted averaging (BCFDPWA), BCF Dombi prioritized geometric (BCFDPG), and BCF Dombi prioritized weighted geometric (BCFDPPWG) operators by utilizing the Dombi aggregation operator (AO) with BCF information. After that, by using artificial data, we assess the structural systems to design earthquake resistance buildings with the assistance of the invented method of MADM. To exhibit the dominancy and supremacy of the elaborated work, the advantages, sensitive examination, graphical representation, and comparative study are described in this script.

Structural assessment of the stalled building in Department of Industrial Engineering, Andalas University, Indonesia

The construction of the Industrial Engineering Department building is an effort to support the educational infrastructure at Andalas University. However, the building construction process was stopped because the contractor had terminated the contract (breach of contract) and it took a long time to continue the construction. Before that, a structural evaluation of the building structure should be conducted due to the update of the building standards. In this study, the structural evaluation was carried out by analyzing and modelling the building using ETABS v.18 software, as well as loading analysis on the building regarding current Indonesian building standards such as SNI 1726-2019 for earthquake resistance building design, SNI 2847-2019 for requirements of the structural concrete building and SNI 1727-2020 for building minimum design loads. The results of the analysis show that several structural beams did not have a strong enough capacity to withstand the working loads, where the ultimate moment and shear values due to the influence of acting loads were more than the nominal moments and shear values. Retrofitting of the weak structural beams using the CFRP wrapping method was recommended to improve the structural capacity of the building.

РАСЧЕТ МОСТОВ НА ДЕЙСТВИЕ СЛАБОГО (ПРОЕКТНОГО) ЗЕМЛЕТРЯСЕНИЯ.

According to Russian standards calculating bridges is made only for the action of a strong (maximum design) earthquake with a frequency of once every 500-5000 years. In the whole world practice there is a transition to multi-level designing, which considers several structure limit states and the corresponding design actions. The paper discusses the features of such transition in relation to bridges, with the whole range of issues related to such calculations being described. These issues include specifying limit states, specifying the level of design action, setting load combinations and design schemes for bridges, and taking into account damping in bridge elements. The developed proposals require setting the allowable repeatability of certain limit states and are based on the instrumental part of the current the seismic scale standard.

Running safety assessment of trains considering post-earthquake damage state of bridge–track system

A bridge–track system (BTS) is inevitably damaged during an earthquake; this is reflected in its stiffness deterioration and residual deformation, which affect the post-earthquake running safety of trains. The influence of the post-earthquake damage state of an actual BTS on train running safety remains unclear. Hence, this study mainly discussed the influence of post-earthquake bridge–track damage state and residual deformation on running safety and established a safe speed limit for trains under different seismic intensities. A finite element (FE) model of a simply supported railway BTS was established using the OpenSees software. A nonlinear seismic response analysis was performed under different ground motion intensities (0.1, 0.3, and 0.6 g for frequent, design, and rare earthquakes, respectively), and bridge damage, fastener damage, and residual deformation of the rail after the earthquakes were studied. An OpenSees-TRBF (train-rail-bridge-foundation coupled system dynamic analysis software, TRBF) co-simulation method was developed to analyze the running safety of trains after earthquakes under a damaged state of the BTS based on the TCP/IP communication interaction technology. A safe speed limit for trains considering the post-earthquake damage state and residual deformation was proposed, providing a reference for the post-earthquake capacity of trains. The results of the BTS seismic damage analysis showed that the residual displacement of the bearing was the fundamental reason for the change in the rail line shape, and fastener damage mainly occurred in the range of 2–4 fasteners at the end of the girder under the design and rare earthquakes. The results of the running safety analysis showed that, if damage to the BTS is ignored, the running safety after an earthquake will be misjudged. Based on the continuous overrun time limit index, the running safety indices for ground motion intensities of 0–0.4, 0.4–0.5, and 0.5–0.6 g could meet the speed requirements of 350, 300, and 150 km/h, respectively. This study provides some references and suggestions for the running safety of trains following an earthquake.

How do tall buildings affect seismic earth pressures on their basement walls?

The construction of tall buildings has recently undergone exponential growth in major cities, creating new challenges in earthquake engineering and design. For instance, existing analytical procedures for evaluating seismic lateral earth pressures on basement walls connected to these buildings typically ignore the inertia and dynamic properties of the superstructure. The inertial forces from a tall superstructure may cause additional displacements and rotations in its basement, affecting the distribution and magnitude of seismic lateral earth pressures. These additional soil-basement-structure-interaction (SBSI) effects are currently not well understood. Hence, the applicability and reliability of existing procedures to the basements of tall buildings remain questionable. In this paper, we use an experimental-numerical approach to provide insight into how the lateral resisting system of tall superstructures may impact the magnitude and distribution of seismic earth pressures on basement walls buried in dry sand and gravel. Numerical simulations are first validated in 3D using a prior centrifuge experiment that included a simplified model of a 42-story, high-rise structure in medium-dense, dry sand. Then, the numerical tool is used to perform 156 2D, nonlinear simulations of more realistic buildings and basements, ground motion characteristics, and sandy and gravely soil profiles. Nonlinear numerical simulations successfully capture the building's inertial and kinematic seismic interactions with the basement and an adjacent underground structure. The subsequent numerical sensitivity study showed that inertial forces from the dynamic lateral movements of the tall superstructure increase the total lateral earth pressures on the basement walls. This increase is particularly notable in the top two-thirds of the basement wall, and it can be approximated by a trapezoidal distribution. These effects and reliability of existing analytical procedures are shown to be highly sensitive to the building's modal frequencies in relation to the frequency content of the input motion as well as the stiffness of the structure-basement system with regard to the underlying soil. The results highlight the importance of considering the building's dynamic properties and inertia in evaluating seismic earth pressures on basement walls to avoid unsafe estimations or the need for overdesign.

INSPECT-SPSW: INelastic Seismic Performance Evaluation Computational Tool for Steel Plate Shear Wall Modeling in OpenSees

Modeling Steel Plate Shear Wall (SPSW) behavior can be computationally demanding. This is especially true when high-fidelity modeling is carried out via shell or 3D solid elements. It has been shown that SPSW behavior can be captured with adequate accuracy through the strip method via nonlinear truss elements idealization. The widely accepted and reliable analysis platform, OpenSees, requires text-based input (.tcl) files created by a skilled programmer. Hence, a Pre/Post-processing User Interface (UI) software package (INSPECT-SPSW) is introduced herein. With basic input, the INSPECT-SPSW package allows the user to create the OpenSees (.tcl) input file, run different nonlinear analyses, and retrieve and visualize the output. In addition, the UI includes illustrated wrappers for several OpenSees commands for various material definitions, plasticity modeling options, modal analysis, and nonlinear analysis types. Validation and verification were conducted against published results of experimental and numerical cyclic loading specimens. The user-friendly interface successfully created accurate models that capture the SPSW nonlinear behavior, including the various possible failure mechanisms. e.g., beam or column plastic hinging, web plate yielding, etc. With demonstrated performance and intuitive UI, INSPECT-SPSW is expected to facilitate the broad adoption of the strip method for Performance-Based Earthquake Design (PBED) of SPSWs.

Field Investigation on Reinforced Concrete and Masonry Buildings Damages after November 23, 2022 Gölyaka (Düzce) Earthquake

A strong earthquake with a moment magnitude of [Formula: see text].9 according to the Disaster and Emergency Management Authority (AFAD) occurred at 04:08 local time on November 23, 2022, in Gölyaka district of Düzce province that is located in the Western Black Sea region of Turkey. The earthquake with a shallow focus is 0.82 km away from Kemeryani village of Gölyaka district, which is the nearest settlement. According to observation data, the highest acceleration value of the earthquake was measured as 407.76 gal (0.410 g) in the East-West component measured from the 8102 coded Düzce Central accelerometer station, which is one of the five accelerometer stations closest to the earthquake zone. There was no loss of life in the earthquake, in which 93 people were injured. However, damages occurred due to the earthquake in structures that were built before the year 2000 and did not receive good engineering and supervision services. It has been determined that the structures built after the year 2000 received good engineering and supervision services performed better. The purpose of this study is to ensure that the experience gained as a result of the investigations about the earthquake that occurred will be made permanent and usable. For this purpose, damage and collapses that occurred on the buildings due to earthquake are examined based on field investigation. The types and causes of damage that occurred on both reinforced concrete and masonry buildings are evaluated in detail with considering the conditions of the existing Turkey Building Earthquake Design Code. The seismological characteristics of the earthquake are also evaluated. In addition, the earthquake hazard of Düzce Province is evaluated together with the earthquakes experienced in the past years, which caused significant loss of life and property in the region.

Estimation of soil liquefaction potential in Colombo Port City (Sri Lanka) using several design earthquakes

The Journal of the National Science Foundation of Sri Lanka publishes the results of research in all aspects of Science and Technology. The journal also has a website at http://www.nsf.gov.lk/. 2021 Impact Factor: 0.682The JNSF provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge.Cover :Leatherback (a), green (b - adult & f - hatchling), hawksbill (c) and olive ridley (d) turtles who nest in Sri Lankan beaches, green turtle crawl marks (e) and by-catch of sea turtles in fisheries (c & d)Photo credits: SJ Perera (a & c), WPN Perera (b & e), K Ekaratne (d & f)

PENGARUH RENCANA PENINGKATAN VOLUME TAMPUNGAN TERHADAP STABILITAS TUBUH BENDUNGAN KEDUNG OMBO

The strategy to meet the water demands of Semarang and Demak Regencies involves enhancing the storage capacity of the Kedung Ombo Dam. This augmentation will inevitably alter the typical water level, thereby affecting the stability of the dam structure as it bears a greater load. Furthermore, the Kedung Ombo Dam, which is nearly 32 years old, necessitates re-evaluation since it lacks the full benefit of contemporary design methods. This study is confined to examining the slope stability, both static and pseudostatic, at a steady state flow, with the highest normal water level elevation (elevation +92.00) as the focal point. The slope stability analysis was conducted via the finite element method using the Slope/W in Geo-Studio software. The outcome of the static slope stability analysis indicates that the safety factor of the Kedung Ombo Dam body remains above the minimum allowable safety factor. In the pseudostatic analysis, the safety factor during the Operating Basic Earthquake (OBE) remains above the minimum allowable safety factor. However, during the Maximum Design Earthquake (MDE), the safety factor demonstrates a value that is lower than the minimum allowable safety factor. Nevertheless, the analysis of fixed displacement or permanent deformation reveals that the maximum settlement that occurs during the MDE earthquake does not exceed 50% of the available freeboard.

Illustrating the impact of earthquakes: Evidence-based and user-centered recommendations on how to design earthquake scenarios and rapid impact assessments

Risk-based earthquake scenarios and rapid impact assessments can meaningfully improve how societies prepare for and deal with earthquakes. However, this is only the case when they are understood and perceived as useful to support mitigation and recovery actions. In this study, we are among the first to empirically assess how to best design earthquake scenarios and rapid impact assessment meeting the needs of different target audiences. We applied a transdisciplinary, iterative process involving a literature review, expert interviews, workshops with professional stakeholders, and internal reviews to design and improve the scenario and rapid impact assessment that were then tested in a representative survey with the Swiss public (N = 580). The results demonstrate a high perceived importance among all users groups for these products as well as advanced levels of comprehension. A focus was set on depicting uncertainties showing that the most simple visualization only using ranges was best understood and most liked. This supposes that the histograms predominantly used in existing outlets need to be reconsidered. Professional stakeholders and the public were further similarly challenged by more complex visualizations. The public survey further revealed the importance of the cartographic information as a supposedly relevant proxy to answer questions with a geographical reference and a requirement to improve the current version.

Direct displacement-based design of SEDRC systems considering higher mode effects

Self-centering energy-absorbing dual rocking core (SEDRC) system was recently proposed for obtaining damage-free performance under design earthquakes or low damage under extreme earthquakes in steel building structures. Although the SEDRC system can mainly deform based on the fundamental mode shape, the higher modes may significantly impact the structural element forces. This research intends to investigate the effects of higher mode on the seismic performance and structural member force demands of the SEDRC system under earthquakes and propose a performance-based design (PBD) method considering the higher mode effects. The formulation for calculating the design base shear pondering the influence of higher mode is deduced. The detailed design steps and equations for calculating the force demands of structural members are presented. Three archetypes, including nine-, fifteen-, and twenty-story SEDRC systems, respectively, are designed according to the PBD method. Moreover, the other six corresponding archetypes are designed according to the previous design process without consideration of higher mode effects as comparative buildings. Nonlinear dynamic analyses were performed to evaluate the seismic responses of the designed structures. The analysis results validate the high precision of the proposed methodology in designing multi-story to high-rise SEDRC systems.

Experimental Study of Structural Behavior of Banua Tadulako’s House for Earthquake Survivor of Palu

Huntap (Permanent dwelling) is a building intended for people whose houses are affected by disasters. The main requirement is that the building be proven to survive if an earthquake occurs around the Permanent dwelling located in the future.This research begins with the completion of the architectural drawing of the Banua Tadulako’s House (Rumbako) according to input from the Spatial Planning and Settlement Service of Palu City and the Directorate of Housing and Settlement Engineering Development of the Ministry of PUPR. The next process is the preparation of materials and equipment. Structural analysis using SAP 2000 software.Based on the analysis and simulation results, the following results are obtained: The stresses that occur on the surface of the wall do not exceed the allowable stress of the brick wall infill material, The cross-sectional capacity of the reinforcing steel is quite safe against the combination of loading applied to the structure. The basic seismic shear force of the structure capacity from the pushover analysis is 226 kN. More than the design earthquake force of 121 kN. Minimum connection details and truss structural elements have been calculated and qualify the requirements for strength and stress ratio.