Earthquake Resistant Design Research Articles

Architectural And Structural System Design of Precast Concrete Structures In Earthquake Zones

Precast concrete systems, which are the result of industrialization in the field of construction, are faced with the prejudice of insufficient earthquake resistance despite their many advantages and their use is limited in Turkey. These systems, which have proven earthquake resistance if they are designed properly, can be used safely in low-rise or multi-storey buildings with different functions in earthquake zones. The aim of this study is to determine the architectural design requirements of earthquake-resistant precast concrete structures and to reveal the structural system design approaches. In accordance with this aim, the earthquake effect on the structures was summarized and architectural design principles that would contribute to the earthquake resistance of precast concrete structures were determined firstly. Then, earthquake-resistant structural system design approaches of frame, panel, and cell construction were evaluated separately.

Deterministic and Probabilistic Seismic Hazard Analysis of Tindharia, Darjeeling Sikkim Himalaya, India

Abstract The simulation of appropriate ground motion is the main objective in earthquake-resistant designing to mitigate the impact of landslides and structural damages. The seismic hazard studies serve as the basis for quantifying the hazard associated within the particular area over a given time period. In this study, the detailed site specific hazard analysis of Tindharia site as well as Darjeeling Sikkim Himalaya (DSH) region has been carried out to assure the safety of human and infrastructure against seismic risk. The study area is mountainous region on north western side of India, falls in seismic zone IV and V, and is one of the most seismically active regions with vulnerable earthquakes along with fatal landslides. The future large earthquakes are likely to occur in the region due to constant movement of Indian plate towards Eurasian plate. Therefore, the heightened seismic risk increases the demand for seismic studies near the Himalayan belt. Thus, the assessment of associated seismic hazard in the study area has been carried out by deterministic and probabilistic seismic hazard approaches. From the results, the seismo-tectonic map of a 300km radial distance of the study area is developed. The deterministic hazard distribution in terms of peak ground acceleration (PGA) and the PGA and peak spectral acceleration (PSA) hazard maps for 2% and 10% probability of exceedance in 50 years at different time periods have been generated. The updated hazard maps developed in this study play pivotal roles in mitigation measures with better pre-disaster prevention by earthquake resistant design and in preparedness and post disaster rescue in the study area.

Genealogy of development and codification of Yugoslavian earthquake resistant design

This contribution aims to clarify for exposure modellers and vulnerability and seismic risk assessors the basis on which seismic lateral loads have been established in all Yugoslavian seismic design codes since 1948. The particular focus is on JUS39/64 and JUS31/81 seismic design codes since they controlled the seismic safety of Macedonian (and Yugoslavian) exposure for 16 and 41 years, respectively. The analyses and discussions are centred on lateral force coefficients as a primary factor for representing the features of each design level. Presented is in all detail the developed K-Quotient method that efficiently compares inter-code lateral force levels. The method provides the closed solution for simplified lateral load calculation applicable to “stiff” buildings (T ≤ 0.5 s). The presented results are indicative of flexible buildings requiring further research on the subject.

Seismic vulnerability assessment of masonry building supported by STRP isolators

Scrap tire rubber pad (STRP) isolators are made from scrap automobile tires, which are expected to be a low-cost material for earthquake-resistant design of low-to-medium-rise buildings in developing countries. This paper describes the seismic vulnerability of a unbonded STRP (U-STRP) base-isolated masonry building using the finite element method. The three-dimensional model of the U-STRP isolators is placed between the foundation and the building without any bonding between them. As a result, the inertia force of the building is transferred to the foundation through the friction. Two alternative versions of the U-STRP isolator: strip-shaped and square-shaped, are analyzed, which have comparable geometric and stiffness properties. The fidelity of the U-STRP isolator model is confirmed using the numerical analysis and experimental results. The seismic vulnerability of the masonry base-isolated building is determined using the pushover analysis and the fragility curves and then compared to that of the identical fixed-base building. The findings show that masonry buildings with uniformly distributed square-shaped U-STRP isolators suffer low damage and base shear compared to those of the same size of strip-shaped U-STRP isolators. The U-STRP base-isolated masonry building has superior seismic performance to that of an identical fixed-base building, and a square-shaped U-STRP is more effective than the strip-shaped isolator.

Near-Real-Time Strong Motion Acquisition at National Scale and Automatic Analysis.

A strong motion monitoring network records data that provide an excellent way to study how source, path, and site effects influence the ground motion, specifically in the near-source area. Such data are essential for updating seismic hazard maps and consequently building codes and earthquake-resistant design. This paper aims to present the Italian Strong Motion Network (RAN), describing its current status, employment, and further developments. It has 648 stations and is the result of a fruitful co-operation between the Italian government, regions, and local authorities. In fact, the network can be divided into three sub-networks: the Friuli Venezia Giulia Accelerometric Network, the Irpinia Seismic Network, and all the other stations. The Antelope software automatically collects, processes, and archives data in the data acquisition centre in Rome (Italy). The efficiency of the network on a daily basis is today more than 97%. The automatic and fast procedures that run in Antelope for the real-time strong motion data analysis are continuously improved at the University of Trieste: a large set of strong motion parameters and correspondent Ground Motion Prediction Equations allow ground shaking intensity maps to be provided for moderate to strong earthquakes occurring within the Italian territory. These maps and strong motion parameters are included in automatic reports generated for civil protection purposes.

Farklı Dolgu Tipleri için Çerçevelerin İtme Analizi ile Kıyaslanması

Earthquake-resistant building design is becoming increasingly important as a result of destructive earthquakes. Earthquake, which is a natural event that occurs as a result of geological movements, can turn into a natural disaster according to the behavior of the structures under the influence of earthquakes. In this study, a reinforced wall model was compared with other frame types in order to reduce the earthquake effect on the structures. With this reinforced wall model, the building is intended to be more ductile than shear wall systems and more rigid than bare frame systems. Static Pushover Analysis, which is currently and widely used, was used within the scope of performance-based design. The pushover analysis method is explained in detail and applied to all models. Single-storey frame models in order to make comparisons with the analyzes; The frame modeled with bare frame, shear wall frame and reinforced wall model has two different types, 15x15 and 20x20 ( in centimeters) , in total, 4 models. These models were compared and interpreted in terms of ductility and stiffness.

Determination of Earthquake Behaviors of a Reinforced Concrete Building with and without Earthquake Base Isolation

There are many fault lines within the borders of our country, especially the North Anatolian Fault line. For this reason, earthquake resistant structural design is a very important issue in order to prevent possible economic losses after earthquakes, especially the life safety of people living in our country. The main goal in earthquake insulation, which is a new approach in earthquake design of buildings, is to reduce the possible effects on the structure by placing flexible elements in the horizontal direction and rigid in the vertical direction, by greatly reducing the earthquake loads and accelerations acting on the superstructure. In this study, the earthquake behavior of the buildings, which were designed by the Housing Development Administration of the Republic of Turkey and designed as a base isolation support, and the structures designed according to the principles determined in the Turkey Building Earthquake Code 2018 by using base isolation, were determined according to the non-linear time history analysis method. The behavior changes of the structure designed using earthquake base isolation compared to the conventional structure were examined, and the period values, floor accelerations and base shear forces of the two structures were compared. As a result of the results obtained, the positive effects of the period increase and the decrease in floor accelerations in the earthquake insulated structure were revealed.

Architectural And Structural System Design of Precast Concrete Structures In Earthquake Zones

Precast concrete systems, which are the result of industrialization in the field of construction, are faced with the prejudice of insufficient earthquake resistance despite their many advantages and their use is limited in Turkey. These systems, which have proven earthquake resistance if they are designed properly, can be used safely in low-rise or multi-storey buildings with different functions in earthquake zones. The aim of this study is to determine the architectural design requirements of earthquake-resistant precast concrete structures and to reveal the structural system design approaches. In accordance with this aim, the earthquake effect on the structures was summarized and architectural design principles that would contribute to the earthquake resistance of precast concrete structures were determined firstly. Then, earthquake-resistant structural system design approaches of frame, panel, and cell construction were evaluated separately.

A new endurance time analysis method for damage evaluation of high arch dams under the oblique incidence of mainshock-aftershock seismic sequences by wavelet decomposition

Pulse and oblique incidence features that may be generated by near-fault seismic sequences are neglected in current earthquake-resistant design codes for arch dams. To solve the shortcomings of endurance time analysis method which cannot consider near-fault pulse-like ground motions, this paper attempted to develop a new endurance time analysis method by wavelet decomposition to assess the differences in damage mechanisms of arch dams under the cross-stream and stream oblique incidences of near-fault seismic sequences. This study decomposed a typical near-fault earthquake into high-frequency and low-frequency ground motion through wavelet decomposition, which is used to perform several nonlinear dynamic analyses under different seismic intensities and seismic sequence incidence angles. On the basis of dynamic calculations, the local and global damage indices of the dam were presented, with a focus on the comparison of the damage distribution and damage volume ratios of arch dams under the action of single and sequence earthquakes and by analysing the damage mechanisms of arch dams under two diagonal incidence conditions at different peak accelerations. Then, the effects of different frequency components of ground motions on dam damage indices were compared, and finally, additional damage to the dam after the mainshock damage was quantified for various aftershocks. The proposed novel prediction model was used to estimate aftershock damage by considering mainshock damage. The numerical results indicate that the dam damage development is highly complex during original mainshock cross-stream and stream oblique incidences. This finding differs from dam damage that spread from the downstream face to the upstream face during the vertical incidence. The dam damage degree is smaller for the original mainshock stream oblique incidence than for the original mainshock cross-stream oblique incidence. The original aftershock induces stronger damage requirements on the damaged dam during the mainshock than during the high-frequency aftershock. Original and high-frequency seismic sequences with cross-stream and stream oblique incidences do not contribute to variations in dam damage patterns during aftershocks. Therefore, the influence of near-fault pulse impacts and the oblique incidence angle of seismic sequences need to be considered comprehensively in the seismic calculations and reinforcement studies of arch dams.

Development of seismic map for offshore platform design in Indonesia, case study of the North Coast of Java

Indonesia’s design of earthquake-resistant offshore platforms does not yet have specific regulations. The commonly used standard in Indonesia, API RP 2A WSD, does not explicitly state the earthquake return period for offshore structures. A more detailed procedure is described in ISO 19901-2:2004. Two methods are introduced in the standard. First, the simplified method allows the use of earthquake maps with a return period of 1000 years. Second, the detailed method requires a site-specific seismic hazard study to determine the return period of earthquakes. This paper presents the development of seismic hazard maps using a simplified method following ISO 19901-2:2004. The maps are prepared using the probabilistic method with a case study on the North Coast of Java. The results show that the study area falls into seismic zones 1 and 2. The seismic hazard maps can be used for earthquake resistance design for structures with exposure level L2 and L3 based on the seismic risk category following the ISO.

Comparative Earthquake Resistant Design Study of Thin Rectangular 20 Storey Structure in Zone 1 and Zone 3 Using ETABS

Abstract: An earthquake occurs in the form of seismic waves due to sudden release of energy and results inground shaking. During earthquake, seismic waves propagate through the soil which results in structural damage due to movements within the earth’s crust. It impacts the behavior of interactionof components like building, foundation, underlying soils and also overall system behavior. Whenearthquake occurs, the behavior of a building depends on distribution of mass, strength and stiffness. Generally, the buildings are subjected to various types of forces throughout theirexistence. The forces can be static forces due to dead and live loads and dynamic forces due to earthquake. In this study, the analysis is carried out for seismic response of 20 Storey Commercialoffice building for Zone-I and Zone-III regions through response spectrum method in ETABS. Thedesign details such as reinforcement area for beams, columns and shear walls and resultant parameterslike storey displacement, storey drift, storey shear, base shear, PMM Interaction curves,D/C ratios are observed for specified zones

Relation of shear wave velocity variations with depth for different lithologies: A contribution towards mitigating the region's seismic risk

The state of Uttarakhand in India lies in a highly seismically active zone, therefore earthquake re- sistant design criteria have been followed for major construction practice in this region. One of the major inputs for earthquake-resistant design is average shear wave velocity (VS ) at 30 m depth. In the present work, at twenty-six different sites, the Horizontal to vertical spectral ratio (HVSR) technique and multichannel analysis of surface wave (MASW) is used for joint analysis to obtain a one-dimensional velocity model that supports both the HV spectrum and dispersion curve obtained from HVSR and MASW methods, respectively. Shear wave profiles obtained at various sites are compared with the bore log data obtained from drilling and it clearly shows that the (VS ) for the same formation have a strong dependence on the depth at which it occurred. Data from twenty- four shear wave profiles have been used to prepare a linear regression relation of (VS ) for different lithological formations with respect to their depth of occurrence. Root mean square error obtained from the developed relationship for various lithologies clearly shows that the results are fairly well within the range of acceptance. The developed relations have been further validated by calculating Vs profile from bore log data obtained at two new location sites that are not included in the data set used for the preparation of regression relations. A comparison of two velocity sections clearly shows that the velocity profile computed from regression relation matches closely with that obtained from the seismic survey and thereby establishing the efficacy of developed regression relationship for its practical implementation. This developed relation allows soil type classification for zoning purposes.

Hazard consistent vertical design spectra for active regions of India

According to the current Indian Standard earthquake-resistant design code (IS 1893, 2016), the vertical design spectrum is assumed as two-thirds of the horizontal spectrum. However, a previous investigation of the Indian ground motion records suggests that the vertical spectra exceeded the horizontal in many instances, which would render the previous consideration inadequate. Therefore, the current study aims at developing an appropriate recommendation for obtaining vertical design spectra, through development of hazard consistent vertical design spectra for the active regions of India. The vertical design spectrum is generated through scaling of a weighted average vertical-to-horizontal ratio (V/H) ground motion prediction equation (GMPE) to the horizontal component of the uniform hazard spectrum. The uniform hazard spectrum is obtained for the two active regions of India– the Western Himalayas and the North East India through probabilistic seismic hazard analysis and the weighted average V/H model is obtained by combining the V/H GMPE developed for India with several global models. Based on the proposed relations, a structural engineer can obtain site-specific vertical design spectra with ease and accuracy.

Seismic reliability of steel SMFs with deep columns based on PBSD philosophy

Steel special moment frames (SMFs) represent a common structural solution for buildings in earthquake-prone areas. However, when SMFs are selected by structural engineers, one of their main concerns is to satisfy the permissible drifts recommended by codes. As a common option, the use of deep columns may be a feasible alternative to reduce lateral deformation of SMFs. In this paper, the authors explore the performance of steel SMFs with deep columns by evaluating their seismic reliability. Since earthquake-resistant design is moving from the prescriptive-code to performance-based seismic design (PBSD), an alternative safety approach is integrated with the PBSD philosophy. In this way, SMFs are represented by finite elements and excited by seismic loading incorporating all major sources of nonlinearity as material behavior, geometric deformations, and connections of structural members. The novel approach is developed using the first-order reliability method, response surface method, and an advanced probabilistic scheme. The computational benefits and accuracy of the proposed method are validated using traditional Monte Carlo simulation. The implementation potential is showcased with the numerical evaluation of three 9-story steel SMFs: the first one using columns of medium size and the other two considering deep columns. The seismic reliability is extracted for every model considering serviceability performance functions correlated with performance levels of collapse prevention, life safety, and immediate occupancy. In addition, the contribution of the post-Northridge connection in the steel SMFs is incorporated. Finally, without being too much critical, the use of deep columns in the models of this paper seems to be a step in the right direction to reduce weight, decrease cost, and increase structural reliability. However, it must be stated that deep columns considered in the models have no instability concern because of their low slenderness ratios.

Research on the Use of Machine Learning on Building Facades

Artificial intelligence and its sub-branch, machine learning technologies, have developed rapidly in recent years and their use for various purposes has seemed to be increased in various sectors from automotive to medicine, from law to marketing. Similarly, these technologies have begun to be used in the building sector and in the field of architecture. These technologies are being used in many fields in architecture such as feasibility studies, building design, project control, occupational safety, earthquake resistant building design and applications, energy efficient system design, construction with smart construction equipment, smart building design, and smart facade design. Despite this increasing use in the field, it has been determined by the literature review that the number of studies focusing on the use of machine learning in architecture, especially on building facades, is low. In this sense in the study, it is aimed to examine the relationship between artificial intelligence and machine learning technologies with architecture in the context of building facades. Initially in the study the topics and the historical process related to artificial intelligence and machine learning were explained, subsequently the use of technologies on the building facades was examined through examples. In this way, a guiding resource has been created for those who want to work on this subject in the future.

Automated structural design of shear wall structures based on modified genetic algorithm and prior knowledge

Shear wall layout requires repetitive revisions and checks by an experienced designer, which is very time-consuming and inefficient. Therefore, an automated and effective approach to structural design of shear wall structures is needed. An automated generation method of structural model from architectural computer-aided design drawings is described, where the semantic segmentation of buildings based on the connected component analysis, graph structure and Procrustes analysis and an effective parametric modeling approach of shear wall structures integrated with prior knowledge are included. Besides, a modified genetic algorithm with greedy strategy is suggested for shear wall layout optimization. The proposed approach is shown to be effective and reliable through two real-world examples, demonstrating the promising future of automated structural design. This study addressed only the earthquake-resistant design of buildings, and other relevant issues such as beam layout optimization, multi-objective optimization, and economic feasibility of construction should also be addressed in the future.

Seismic response of the long-span steel truss arch bridge with the thrust under multidimensional excitation

PurposeUnder different ground motion excitation modes, the spatial coupling effect of seismic response for the arch bridge with thrust, seismic weak parts and the internal force components of the control section of main arch ribs are analyzed.Design/methodology/approachTaking a 490 m deck type railway steel truss arch bridge as the background, the dynamic calculation model of the whole bridge was established by SAP2000 software. The seismic response analyses under one-, two- and three-dimension (1D, 2D and 3D) uniform ground motion excitations were carried out.FindingsFor the steel truss arch bridge composed of multiple arch ribs, any single direction ground motion excitation will cause large axial force in the chord of arch rib. The axial force caused by transverse and vertical ground motion excitation in the chord of arch crown area is 1.4–3.6 times of the corresponding axial force under longitudinal seismic excitation. The in-plane bending moment caused by the lower chord at the vault is 4.2–5.5 times of the corresponding bending moment under the longitudinal seismic excitation. For the bottom chord of arch rib, the arch foot is the weak part of earthquake resistance, but for the upper chord of arch rib, the arch foot, arch crown and the intersection of column and upper chord can all be the potential earthquake-resistant weak parts. The normal stress of the bottom chord of the arch rib under multidimensional excitation is mainly caused by the axial force, but the normal stress of the upper chord of the arch rib is caused by the axial force, in-plane and out of plane bending moment.Originality/valueThe research provides specific suggestions for ground motion excitation mode and also provides reference information for the earthquake-resistant weak part and seismic design of long-span deck type railway steel truss arch bridges.

Seismic Retrofitting of RC Frame Structure Using Energy Dissipation Device

Abstract: This study examines the performance-based design of structure that is increasing commonly in earthquake resistance design. to ensure any structure possess earthquake resistant design, certain minimum performance objective is desired at different level of seismic excitation. With the help of some devices, Lowto medium rise buildings are performing well forthe seismic actions. In the present work, originally deficient RC frame is analyzed with static analysis and after this static non- linear analysis is performed in which suitable energy dissipation devices are installed sequentially. first analyzed with Viscous fluid Damper then Lead- rubber isolator is used has designed as per performance-based design criteria of G+6 RC frame building. These models are analyzed for important residential use and located at seismic zone IV. Linear static and nonlinear static methods are used to analyze the structure with help of CSI ETABSv18 software. Results which are discussed is minimum performance level, story drift,performance point and performance objective. After analysis of results, structure which is installed with Led-rubber bearing isolator is performed well during an earthquake and satisfy with desired minimum performance level. In case of viscous fluid damper, it is not satisfactory to achieve desired minimum performance up to this extent it helps to reduce floor acceleration.

Seismic Analysis of High-Rise Building Having Lateral Load Resisting Elements with and Without Base Isolation

Abstract: In present work linear dynamic analysis of high-rise building is done and of base isolation is analyzed with lateral force resisting elements like shear wall and bracing, effect of all these structural components is calculated and analyzed on structure having 30,35 &40 Stories. Structure is Located in Earthquake Zone IV. Analysis is done with the help of ETABS 19 software. In base isolation we bifurcate the structure from foundation so the structure remains unharmed from shocks and motion at the time of seismic action. Base isolation is awidely used lateral load resisting system provided to strengthen such buildings but literature survey of Base isolation reveals that Lear Rubber Base isolation is proved tobe determinantal. With the increase in urbanisation use of multi stories building is now in trending because of its high utility in commercial as well as residential. In northern part of India, maximum places are susceptible to earthquake so the basics requirement is to build the safe structure so that no damage to the life takes places. One among various methods of earthquake resistant design is Base Isolation. Various studies were carried out to check the behaviour of different parameters like time period, drift, storey displacement and overturning moment etc. with various types of base isolation. Use of LRB isolation system for high rise buildings was suggested. In thepresent study lead rubber bearing is used for base isolation with structure having shear wall and bracings. G+30, G+35 and G+40 storey structure are analysed. Static, linear dynamic (response spectrum) is performed to study the behaviour of building with lead rubber base isolation system. ETABSv2019 is used to perform the analysis and design. Comparison of fixed base building with LRB is shown and suitability concern is provided. It was observed from the study that Lead Rubber base isolation is more effective for earthquake prone zones.

Seismic Analysis of Irregular Planned RC Frame: Capacity Based Design Criteria

Abstract: This study examines the capacity-based design of structure that is increasing commonly in earthquake resistance design. For making any structure earthquake resistant capacity-based design approach is good to hire because it takes less specialization. Low to medium rise buildings are performing well for the seismic actions when designed as per capacity- based criteria. The other method is to install lateral load resisting element such as shear wall, dampers, base isolators etc. These methods of seismic resistance are costly and requires special attention while installation. On the other hand, capacity based designed approach requires no extra element in frame although making existing frame elements to be stronger. In the present work, three type of irregularity is being taken and those are being imposed over RC frame which has designed as per capacity-based design criteria for four different heights of G+3, G+5, G+7, G+10. Those models are analyzed for commercial use and located at seismic zone IV. Linear static, linear dynamic and nonlinear static methods are used to analyze those models with help of CSI ETABS v19 software. Results which are discussed is modal analysis, storey drift, torsional ratio, ductility ratio, performance point and hinge results. Keywords: Beam column capacity ratio, collapse mechanism, Strong column–weak beam design, plastic hinge, irregularity, geometry, shape and size of the building, ETABS.