Earthquake-resistant Structures Research Articles

Combination of Monte-Carlo and Wang’s methods to estimate the safety-probability of tunnel structure during earthquake

The calculation and design of underground structures subjects to different types of loads, especially the effect of earthquake plays an important role in choosing a structural design solution to ensure the safety of people and vehicles. Besides, the mechanical characteristics of the soil around the tunnel can change along the tunnel axis, so the calculation according to the reliability is necessary and important. This article presents the combination of the Monte-Carlo numerical simulation method and the predetermined solution proposed by Wang to calculate the reliability (non-failure probability) of the earthquake-resistant tunnel structure when it comes to randomness of the thickness of the tunnel structure and the characteristics of the surrounding medium.

Disasters and Hazards: Risk Reduction, Mitigation and Management

Disasters and Hazards: Risk Reduction, Mitigation and Management

The Behavior of Interior Beam-Column Joint Models Using Self-Compacting Concrete with Variations of Shear Reinforcement Subjected to Cyclic Lateral Loads

The joint of a beam-column is crucial due to the distribution of cyclic lateral loads. Therefore, the joint detail must meet the design requirements of earthquake-resistant structures. Casting work in joint zones where the steel reinforcement spaces are close requires concrete materials that are easy to flow. An alternative to overcome the difficulty is using Self-Compacting Concrete (SCC) material. However, the properties of SCC for beam-column joint structures under earthquake loads still need to be studied further. This study aimed to analyze the behavior of the Interior Beam-Column (IBC) joint using SCC with variations of shear reinforcement subjected to cyclic lateral loads. Three types of shear reinforcement were modeled using numerical analysis. Variations of horizontal and diagonal shear reinforcements were compared to determine the best performance. The SCC-S3 IBC joint model with horizontal and diagonal shear reinforcements achieved the highest lateral forces and resisted compressive and tensile stresses in the largest stress contour and better stiffness degradation than other models of SCC IBC joints. The results showed that the SCC-S3 IBC joint with a combination of horizontal and diagonal shear reinforcements showed the best performance.

Seismic Retrofit using ETABS

In India, Multi-storied structures built are deficient of land and have to carry maximum load. Earthquake could be a circumstance which might result in the failure of the structure. Buildings are to be created so that they are safe to live in and the structure before failure should possess ductile property. To prevent structures from failing and from serious damages the structures before construction should be analyzed for its seismic performance along with support reactions and wind calculations both are to be included in the design of an earthquake resistant structure. The primary objective of present study is to make earthquake resistant structure by retrofitting its columns and the process is known as column jacketing. The retrofitted structure is analyzed in the E-tabs software. For this purpose, a retrofitted G+5residentialbuilding is considered. Calculations are done for an earthquake in seismic zone V. To guarantee the safety of the structure all the forces acting on the structure including the lateral loads due to wind and seismic excitations are considered. Because of the jacketing the column strength and the overall stability of the structure will increase. By using IS Code (IS 15988-2013), the jacketing will be done in E-tabs software. After the jacketing the various responses including bending moment, shear force of existing building will be studied under various loads for an earthquake in seismic zone V.

Stochastic Model to Characterize High-Frequency Ground Motion at Depth Validated by KiK-Net Vertical Array Data

ABSTRACTThe design of important structures for earthquake resistance requires an assessment of the local seismic hazard. One of its essential components is a site response that evaluates the amplification and attenuation of ground motion on a local scale. The shaking on the ground surface (in which it is generally measured) differs from the one at a depth; therefore, there is a need to characterize the ground motion at depth for important underground structures and buildings with deep foundations. In this study, we introduce a method to characterize the high-frequency (>1 Hz) ground motion at depth. The method makes use of a novel stochastic model (SM) that relates the ground motion at depth and on the surface in the Fourier domain. The SM is physics-based, its spectral amplification resembles an empirical 1D site response, and it allows reliable full-waveform ground-motion predictions. The method is validated through the comparison with empirical surface-to-borehole amplification curves observed in 144 selected KiK-net vertical arrays in Japan. Using a frequency range of 0.1–50 Hz, we identified 36 and 83 sites with a good and partially good mutual fit of theoretical and empirical amplification curves, respectively. Finally, we demonstrate the performance of the method in two diverse applications. First, we design a Bayesian inversion of the empirical surface-to-borehole amplification to retrieve the S-wave velocity model and an effective value of t* (the path-integrated effect of the quality factor). This inversion is applied to all selected KiK-net sites. Second, we perform a full-waveform prediction of the ground motion at depth from surface recordings of the 2018 northern Osaka Mw 5.6 earthquake. Both of these applications demonstrate a good performance of our SM in a broad frequency range.

Performance of Mid Rised RCC Structure using Flat Slab System

Flat-slab building structures possesses major advantages over traditional slab-beam-column structures because of the free design of space, shorter construction time, architectural –functional and economical aspects. Because of the absence of deep beams and shear walls, flat-slab structural system is significantly more flexible for lateral loads then traditional RC frame system and that make the system more vulnerable under seismic events. The critical moment in design of these systems is the slab-column connection, i.e., the shear force in the slab at the connection, which should retain its bearing capacity even at maximal displacements. The behavior of flat slab building during earthquake depends critically on ‘Building Configuration’. This fact has resulted in to ensure safety against earthquake forces of tall structures hence, there is need to determine seismic responses of such building for designing earthquake resistant structures. Response Spectrum analysis is one of the important techniques for structural seismic analysis. In the present work analysis of 4 models of multi-storied RCC Flat slab structure is carried out by response spectrum analysis. The BIS guideline in IS 1893:2002 says “Regular and Irregular Configuration to perform well in an earthquake, a building should possess four main attributes, namely simple and regular configuration, and adequate lateral strength, stiffness and ductility. Buildings having simple regular geometry and uniformly distributed mass and stiffness in plan as well, suffer much less damage than buildings with irregular configurations”. Similarly, in IS 4326:1993 it is mentioned that “The building should have a simple rectangular plan and be symmetrical both with respect to mass and rigidity so that the center of mass and rigidity of the building coincide with each other.” But the limiting “plan aspect ratio” and “Slenderness ratio” for the regular structure is not prescribed. This study is concerned with the behavior of structure having same plan area but different plan aspect ratio (L/B) and slenderness ratio (H/B) under seismic condition. The structures are simulated in ETABS software and analyzed using Response Spectrum method.

COMPARATIVE STUDY ON THE EFFECTS OF SHEAR WALL AND BRACING ON MULTISTORIED BUILDING

High rise structures are susceptible to failure and collapse in case of earthquakes. Now a days, shear wall and steel bracings are most popular systems to resist lateral loads due to earthquakes. Both the systems have significant roles in reducing the damage caused due to lateral loads in case of an earthquake. In this study, an attempt has been made to study the performance of a G+9 story building with shear wall and bracing in seismic zone V and comparison has been made between the two systems to find the most suitable earthquake resistant structure. Response Spectrum Analysis has been performed in the software ETABS. The performance is evaluated on the basis of story displacement and story drift.

Reliability assessment of moment resistance frames under earthquake loads

In this study a single bay three storey Moment Resisting frame with bracing and without bracing with different dimensions of columns, Beams have been chosen to perform the study on a Semi -Rigid structure. The frame is analyzed by mode superposition method. For earthquake resistant Structures as proposed by the IS 1983(Part1): 2002 suggest that column must be stronger than beams. A parametric study is made by varying the Moment of inertia of beam section. The ratio of height to width is greater than unity ensuring the frame as Moment resisting frame. The frames are filled with masonry and it is modeled as a braced member for the frame. Two types of frames were studied one with bracing and the other as bare frame. Generalized computer program in MAT LAB has been developed for static loads. An Elcentro earthquake has been scaled and the frames were analyzed one with bracing and other is bare frame. A reliability assessment is performed on the two types of the frames by considering the uncertainties in the Geometry, Strength and loads.

Pengaruh Variasi Girder Terhadap Perilaku Struktur Atas Jembatan Beton Prategang Akibat Gempa Horizontal

Earthquakes are dangerous natural disasters and cause damage on a large scale. Therefore, this study aimed to determine the mass participation of the structure, structure capacity, and performance levels. The analysis was carried out based on the spectral response, pushover, and FEMA-356 methods. In anticipation of the damage, the design of earthquake-resistant structures has become essential in structural design, especially in the bridge structure design. The bridge samples in this study were type I prestressed concrete bridges with a length of 37 m and a width of 4 m using ten variations of girders located at the Temef Dam. The results obtained are the most critical structural conditions occur in the transverse direction. The base shear maximum capacity is more significant in the longitudinal direction than in the transversal direction. The maximum displacement capacity is higher in the transversal direction than in the longitudinal direction. The effect of cross-sectional area and cross-sectional inertia of the beam girder on the structural’s capacity is the greater the cross-sectional area and inertia of the beam girder, the greater the capacity of the structures. All of The structure performance levels were Immediate Occupancy (IO).

Comparative Analysis Study on Construction Cost Between Concrete Structures and Steel Structures Buildings in Surabaya

High-rise buildings in Indonesia must be designed resistance to receiving earthquakes. This is because the earthquake load that occurred in Indonesia has a high intensity. So that existing buildings, especially multi-story buildings must ensure good performance in receiving earthquake loads. This effort aims to maintain the safety of its users. Several aspects that need to be considered in designing earthquake-resistant buildings are structural performance and construction costs. Therefore, in this study, we will discuss the designed of earthquake-resistant structures by making comparisons on concrete structures and also steel structures which will then analyze the cost of the structure for the structures that have been analyzed and designed. From the results of the analysis, for the same conditions, earthquake resisting frame with reinforced concrete construction, it requires cheaper construction costs compared to steel construction. Concrete construction requires a structural cost of Rp. 19,030,188,114.0 and for a steel structure of Rp. 72,206,697,860.7. This is certainly not a conclusion that concrete construction is superior to steel construction. Because even though it is more expensive in terms of cost, steel construction is quite superior in terms of quality, time efficiency and ease of implementation.

Seismic Behavior of a Steel Beam-to-Concrete-Filled Steel Tubular Column Connection Using External Diaphragms

This paper investigates the seismic behavior of a steel beam-to-concrete-filled steel tubular column connection with external diaphragms. In addition to the multiple advantages observed for manufacturing and assembly, this type of connection is expected to provide an adequate plasticizing mechanism based on its ductility, energy dissipation and moment resistance capacity. However, guidelines have not been provided for this type of connection within the AISC 358 standard, which makes experimental studies under cyclic loads necessary. This work presents such a study, which was carried out in accordance with the FEMA 350 standard for earthquake-resistant structures. The results for the failure modes, hysteretic performance, strength and stiffness degradation, rigidity classification and energy dissipation are provided and analyzed. The results indicate that this connection exhibits large hysteretic loops and develops ductility and dissipation capacity, as expected. More importantly, the maximum rotation of the beam was 0.07 rad with a resistant moment above 80% of the beam capacity measured from the face of the column. Thus, the ductility design requirements for earthquake resistance are met according to the current regulations. Consequently, the proposed connection is suitable for use in special moment frame structures located in areas of high seismic threat.

COMPARISON OF MRF AND CBF STRUCTURAL RESPONSE TO EARTQUAKE IN OFFICE BUILDING SURABAYA

Indonesia is a country that prone earthquakes. Therefore, knowledge of earthquake-resistant building construction is needed in reducing the risk of damage caused by earthquakes. There are several methods of earthquake-resistant construction planning, one of which is the pushover analysis method. Pushover is a nonlinear static analysis method in which the structure is subjected to gravity loading and displacement-controlled lateral loads which continue to increase through elastic and inelastic behavior until the final condition. One of the popular construction materials in structural planning is steel construction, which has a uniform structure, lightweight, strong, and easy to work with. In modeling earthquake-resistant structures, several popular models are the MRF and CBF models. MRF is a structural configuration model configured on beams that are firmly connected to columns. Based on a rigid beam-column connection, the moment frame cannot be moved laterally without bending the beam or column depending on the connection geometry. Results The case study on the comparison of the two structural models concluded that in the design of earthquake-resistant steel structures using the pushover method, it was found that the MRF structure had higher ductility than the CBF, namely 2.1:1.6.

Structural Analysis of Maimun Palace Against Earthquake

Timber is one of the most used natural building materials in the world, and it is one of material construction that existed long before science being discussed. Seismic performance of timber structure is quite satisfying, because of its capability to withstand earthquake forces, and timber has been used from traditional house to high rise building. A multi story construction of timber material that still stand strong until now is Maimun Palace, which is a cultural heritage in the city of Medan that must be preserved. So it is necessary to do an analysis to determine the concept of the structure of the Maimun Palace. As a royal palace, Maimun is such a large timber house with complex architecture, so that a comprehensive survey must be done. Surveys carried out include interview with palace guard and royal descendants. The Maimun Palace structure is also modelled into frames and 3D models. The result of Maimun Palace research is that this palace applied the concept of earthquake-resistant building structures which are also outlined in the Indonesian technical guidelines.

Costing and Estimation of Earthquake Resisting Structure: A Review

Abstract: This review report is the analysis of costing and estimation of different earthquake resistance structure and which method will me most economical and efficient method for the construction of any structure which is under the effect or lies in the region of the high seismic zones of the earth . To prevent structure from the earthquake excitation , nowadays several techniques are used such as Dampers , Base Isolation, TMD etc… this paper is a detailed report carried out by the various researchers on various engineering structure by professors from all over the world and the results.

Analysis & Design of an Earthquake Resistant Multistory Apartment Building in all Seismic Zones to Obtain the Increment in the Required Percentage of Weight of Steel Reinforcement

For designing of an earthquake-resistant structure we follow Indian Seismic design codes are exclusive to a particular country or region. Moreover these seismic codes considered all the criteria such as building typologies, accepted level of seismic risk, local seismology. IS 1893 is an Indian seismic code that provides the seismic zone map and specifies seismic design force. The Bureau of Indian Standard (IS: 1893 (Part-1) 2002) classified India into 4 seismic zones (i.e. Zone II, Zone III, Zone IV & Zone V) and the code allocates 4 levels of seismic intensities as zone factors. But this code does not provide any information regarding how much of required percentage of steel-reinforcement has been increased from zone to zone. The main objective for presenting this project is to obtain the increment in the required percentage of steel-reinforcement for various zones by analyzing a multistory Apartment Building with Stilt + G + 3 Floors as per Indian Standard Codes IS 456 : 2000 and IS 1893 (Part – 1) 2002 using STAAD-Pro Software.

An Overview of the Seismic Elastic Response Spectra and Their Application According to Mexican, U.S., and International Building Codes

The design of earthquake-resistant structures by applying traditional or performance-based seismic analysis methods involves two large variables: the seismic risk of the area and the physical characteristics of the structure. Before analyzing any building, it is required to determine the seismicity in the location to evaluate the accelerations that the structure must withstand by deterministic or probabilistic methods. The typical results of a seismic study are the uniform hazard spectra in the rock layer related to a specific return period and structural damping. The building codes use different methods to obtain the elastic response spectra, seeking to offer simple procedures by using parametric factors to consider the soil type; however, the procedure tends to return conservative estimates. On the other hand, site-specific spectra offer accurate and less conservative acceleration values, with the disadvantage of an extensive and costly mathematical process, justifying their application mostly to important structures. This review article gives the state of the art of seismic elastic response spectra using probabilistic seismic hazard maps as inputs, taking into account the importance of the structure and the soil type, according to Mexican, U.S., and international building codes.

EVALUATION OF SEISMIC IMPACTS OF STRONG EARTHQUAKES IN VARIOUS PERMAFROST AND SEISMIC ZONES OF THE MONGOLIAN-SIBERIAN REGION

Based on the study of the features of seismicity within the limits of continuous permafrost and in transitional climatic zones, the influence of natural and climatic factors on the magnitude of seismic impacts is revealed. The results of studies carried out to develop a regional methodology for predicting the parameters of seismic effects of strong earthquakes in the Mongolian-Siberian region during permafrost degradation are summarized. These results are based on the data of complex geophysical measurements. They are aimed at developing methods and techniques for assessing the seismic impacts of strong earthquakes on critical engineering structures located within the permafrost zone and at developing recommendations for conducting seismic micro zoning in various seismic-climatic zones of Siberia and Mongolia, taking into account potential earthquake sources.The main goal of this study is to use the data obtained in planning and construction in seismically active permafrost areas. The developed methods and approaches are presented at the current level of requirements for the design of earthquake-resistant structures in the permafrost zone in specific areas: at the Uyanga site sum, located in Northern Mongolia, and at the Tupik site (using the example of the construction of a tailings dam), located in Russia in the Zabaykalsky Krai (Transbaikal Territory). The first section is located in the zone of insular permafrost with a probability of earthquakes of VIII-degree intensity. The second is in the area of continuous permafrost with a likelihood of VII-degree earthquakes.The proposed and implemented integrated methodological approach makes it possible to obtain at the present level of research for the natural and predicted state of soils in the foundations of designed structures a set of seismic characteristics (accelerograms, spectra, frequency characteristics) and the main parameters of seismic effects for predicted strong earthquakes (maximum accelerations, prevailing frequencies, maxima spectra and resonant frequencies). The noted set of characteristics and parameters of seismic effects meets the modern requirements of designers. It should be accounted for earthquake-resistant structures located in various seismic-climatic zones of the Mongolian-Siberian region.

Dynamic Seismic Analysis of Multi Storey Buildings in Seismic Zone V

Abstract: In India, multi-storied buildings area unit sometimes created because of high value and deficiency of land. Earthquake could be a phenomenon which might generate the foremost harmful forces on structures. Buildings ought to be created safe for lives by correct style and particularisation of structural members so as to possess a ductile sort of failure. To protect such civil structures from significant structural damage, the seismic response of these structures is analyzed along with wind force calculation and forces such as support reactions and joint displacement are calculated and included in the structural design for a vibration resistant structure. The primary objective is to make associate earthquake resistant structure by enterprise seismal study of the structure by static equivalent methodology of study and do the analysis and design of the building by using STAAD PRO software in both static and dynamic analysis Keywords: Dynamic Seismic Analysis, Staad.Pro.

Seismic and Wind Analysis of RCC Building with Different Shape of Shear Wall and Without Shear Wall

Abstract: In India, about 50-60% of the total area is vulnerable to the seismic activity. Earthquakes are the vibrations or the motion of the ground due to release of energy. The vibrations or ground motion are the important factors to analyze and design, the earthquake resistant structure. So, to reduce the impact of earthquake different efforts has been done in this field. Basically, earthquake exerts lateral as well as vertical forces so to dissipate those forces and the vibration in system earthquake resistant structure has been design. The design of earthquake resistant structures depends on providing stiffness, strength and inelastic deformation which withstand the earthquake forces. As the height of the structure increases the lateral loads acted on the structure increases and decrease in the stiffness, so to counteract those shear walls and different damping devices has been used. Keywords: IS Code 1892-Part-1:2016; U - Section, Z- Section, H-Section, T-Section

Comparison of Seismic Zone-II & Zone-V With Respect to Wind Effects on High Rise Structure Using ETABS

Abstract: Reinforced concrete (RC) framed buildings with ground parking are commonly seen in major cities. These RC framed structures are constructed in densely populated cities of developing countries all around India. Earthquakes in the past have major effects on the life and economy as to the buildings and infrastructure was poorly built. Earthquake and wind are both juggernaut as they cannot be stopped in any way, though the solutions are provided only to safeguard the buildings. It is therefore necessary to analyse and modify the building elements satisfactorily to withstand earthquake and wind effects. The Indian code for wind load resisting structure is prepared for analysis of the building and to design the structure for resisting wind loading effects. The wind loading is predominant in effect for three seconds. When the wind loading is taken account the internal pressure of wind and external pressure of the wind loading is taken into account. Wind acts on the surface that is been exposed to it. Mostly windward wind is considered to act on the building. The parameter from analysis of the wind loading on the structure is compared to seismic loading in different zones. Practically seismic effect on building is unpredictable though there is specification suggested in IS code for designing of earthquake resistant structure. The structure is accordingly designed and analysed with proper method with respect to the building height and plan aspect. The response of the building to lateral forces of seismic loading is considered to be in horizontal direction whereas the force acting in the vertical direction is negligible. The response of the building is considered to the same movement that of the shaking to earth motion. The response of building in wind loading effect is compared with response of the elements in seismic loading effects. Up to a certain height wind effect is considered to be same. Seismic loading affects from the foundation itself and the lateral force shake the building in the direction of earthquake motion. The design criteria can be changed when building can be efficiently analysed for both wind and seismic effect. With the help of comparison of the building structure in seismic and wind loading effect, the building can be designed safely if in the analysis the structure is shown failure. Precautions can be adopted in designing of the building material or the building elements. The consulting structural engineer needs to design, and build to safeguard the building from the seismic and wind effect Keywords: Earthquake, Bending moment, Seismic zones, Wind, Direction, Effects.