Criteria For Earthquake Resistant Design Research Articles

Dynamic Analysis of Multi-Storey Building for Minimization of Lateral Displacement due to Earthquake Using Shear Wall

Shear wall are one of the most commonly used in Multi-Storey buildings for resisting the lateral load. In this paper, the multistorey building is modeled and analyzed by STAAD-Pro Software. Building with shear wall is analyzed using STAAD-Pro software and the comparison is done withmodelwithout shear wall. The main focus on the studies of seismic behavior of shear wall in multi-storey building and it will be discussed in detail. The calculation is done by using the IS Code IS 1893:2002, criteria for earthquake resistant design of structures part 1 general provisions and buildings. And the use of IS456:2000, and IS875:1987also have been done in this paper. The results of Displacements and storey drift havebeen computed in both the cases with and without shear wall in STAAD-Pro by using Response Spectrum Method and areobserved as, buildings, employing shear walls at the exterior corners leads to an impressive 77.28% reduction in displacement, while placing them in the middle of the exterior wall achieves a slightly higher reduction of 77.63%. This emphasizes the effectiveness of shear walls in both configurations, with a marginal advantage for the latter.

Comparative Analysis of Multistorey RCC and Semi-Rigid Steel Frame with Cross Bracings Subjected to Mainshock and Aftershock Earthquake Sequence

Strong Ground Motions have a significant impact on structural analysis and design. Seismic evaluation is deemed necessary for the quality, reliability, and feasibility of existing and developing structures. Earthquakes are even more disastrous when a mainshock is succeeded and preceded by aftershocks of higher magnitude. Most of the time, these aftershocks are ignored during analysis. In the last few decades, steel buildings have been crucial to the construction sector. On the other hand, RCC frames are commonly designed structures for commercial purposes and cost-effectiveness. IS 1893 (Part:1)-2002 Criteria for Earthquake Resistant Design of Structures and IS 13920-2016 Ductile Detailing of RC Structures Subjected to Seismic Reactions are majorly used for Seismic Analysis. Steel bracings in the structural system increase the ductility and stiffness of the frame structure. That can be arranged in a variety of ways, such as X, diagonally, alternatively, V, inverted V, K, etc. Cross bracings are used in this paper for the design of a typical multi-story (G+9) semi-rigid steel frame and a typical RCC frame is designed of the same dimensions. Both the frames are modelled and compared using ETABS software and a static nonlinear Time History analysis is executed to examine the performance of both the frames under the Mainshock and Aftershock of Chamoli earthquake. The Mainshock and Aftershock results of the Chamoli earthquake are extracted from the Centre for Engineering Strong Motion Research Ground Motion Database. Base shear, joint displacement, kinetic energy, and story displacement are a few of the variables of Time History Analysis that affect how well a building performs during mainshock and aftershock earthquakes. When analysing the outcomes, it is important to take into account that each of these factors significantly affects how a building responds to seismic loads.

Seismic hazard and risk in Bhutan

We present the first modern seismic hazard and risk assessment in the Bhutan Himalaya. We used a fault-based probabilistic seismic hazard analysis based on fault locations, slip-rates, and paleoseismic earthquake data. We worked with two seismic intensity measures: the peak-ground acceleration (PGA) and Modified Mercalli Intensity (MMI). We extend the hazard analysis to risk by using local building distribution data and making various assumptions about building distribution and fragility. We find, unsurprisingly, that the Main Himalayan Thrust (MHT) is the primary source of hazard, with oblique strike-slip faults cutting across and beneath the Himalaya, and extensional grabens on the northern edge of Bhutan a secondary hazard. The hazard is highest in the southern part of Bhutan where the MHT is shallow, and site conditions lead to amplification of shaking. The risk does not reflect the hazard solely, but also the distribution of exposure, which is concentrated in the cities. We also simulated the 1714 MW8 earthquake, producing 10,000 possible shakemaps in terms of PGA and MMI; we find that many locations could experience PGA values of over 1 g, and on average, up to 18% of the Bhutanese population could be affected. Refining the probable frequency of larger events on the MHT in this region, developing local ground motion prediction equations, creating tailored vulnerability models for typical Bhutanese buildings, and improving the exposure mapping would most improve the hazard and risk results shown here. The existing building code of Bhutan, adopted from the Indian Seismic Zonation of 2002 (BIS-1893 in Indian standard criteria for earthquake resistant design of structures, Part 1—General provisions and buildings, New Delhi, 2002), uses a PGA of 0.36 g uniformly applied across the entire country. Our study, however, presents a non-uniform hazard level across the country and thus questions the relevancy of the current code of construction practices in the country.

Strong ground motions from two moderate size (Mw5.5) Kachchh intraplate earthquakes, Gujarat, India

During 2006–2016, a strong motion seismic network of twenty 3-component accelerogarphs was deployed by the National Geophysical Research Institute, Hyderabad, India, in the epicentral region of the 2001 Mw7.7 Bhuj earthquake. On 7 March and 6 April 2006, two earthquakes of Mw5.5 have occurred in the Kachchh seismic zone, which led to an excellent dataset from 16 to 18 strong-motion accelerograph sites. This dataset enabled us to estimate strong motion parameters for these earthquakes that allowed us to examine the suitability of the design response spectra of BIS (criteria for earthquake-resistant design of structures, part I—general provisions and buildings, Bureau of Indian Standards, 2002) in Kachchh, Gujarat. Our study reveals that the estimated normalized response spectra at strong-motion accelerograph sites, which are lying in tertiary formations or near a zone of geological contact between Jurassic and tertiary formations, exceeded the design response spectra at 0.07–0.2 s, correlating with complete collapse of low-rise buildings, water tanks and dams in the area during the 2001 Bhuj earthquake. While the normalized acceleration spectrum of hard sediment (rock site) is found to not exceeding the design spectrum, correlating with the lack of damage in the Mesozoic hill zone. The estimated normalized acceleration spectra at SMA sites lying on hard sediments of Jurassic/Mesozoic formations are found to be lower than the design spectra, which suggests that these stations are less hazardous. We also notice that spectral acceleration values at few sites lying on quaternary formations have exceeded the design spectra at 3–4 s, suggesting these sites hazardous for engineered reinforced structures like bridges. Our estimated mean pseudo velocity spectra show peaks at 0.2, 0.5, 1.2 and 6 s. The peak at 6 s probably can cause damages to the reinforced engineered structures while the peak at 1.2 s could be causing damages to the multistoried reinforced buildings, as observed during the occurrence of the 2001 Bhuj mainshock. Thus, our estimated normalized acceleration spectra show peaks exceeding the design spectra at shorter (0.07–0.2 s, 0.5 s, 1–1.2 s) as well as longer periods (3–4 s, 6 s), which could be attributed to local site effects. We also notice that the modeled normalized response spectra for the shallow March event shows a better correlation with the NGA West2 model for tectonically active regions of US while the modeled normalized spectra for the deeper April event suggest a better correlation with the NGA east model for the stable parts of USA. We propose that the design spectra for the Kachchh region, Gujarat, India, should be modified incorporating local site, path and source effects.

Ground motion modelling in northwestern Himalaya using stochastic finite-fault method

This study presents estimates of bedrock level peak ground motion at 2346 sites on a regular grid of 0.2° × 0.2° in northwestern (NW) Himalaya from 543 simulated sources, using the stochastic finite-fault, dynamic corner frequency method, with particular emphasis on Kashmir Himalaya. The earthquake catalogue used for simulating synthetic seismograms is compiled by including both pre-instrumental and instrumental era earthquakes of magnitude Mw ≥ 5, dating back to 260 AD. Acceleration time series thus generated are then integrated to obtain velocity and displacement time series, which are all used to construct a suite of hazard maps of the region. Expected PGA values for the Kashmir Himalaya and Muzaffarabad are found to be ~ 0.3–0.5 g and for the epicentral region of the 1905 Kangra event, to be 0.35 g. These values are consistent with other reported results for these areas e.g., Khattri et al. (Tectonophysics 108:93–134, 1984) and Parvez et al. (J Seismol, 2017. https://doi.org/10.1007/s10950-017-9682-0 ). The PGA values estimated in this study are in general found to be higher than those implied by the official seismic zoning map of India produced by the Bureau of Indian Standards (BIS in Indian Standard criteria for earthquake resistant design of structures part 1 general provisions and buildings (Fifth Revision), vol 1, no 5. Indian Standard, 2002). Even the acceleration-derived intensities for most regions are found to be higher compared with those observed, which apparently is due to the use of a longer duration catalogue (260 AD–2016) for simulation not covered by the observed intensity catalogue and higher magnitude ascribed to historical events. Major events in Kashmir Himalayas, such as those of 1555, 1885 and 2005, are simulated individually to allow comparison with available results. Simulated pseudo-acceleration and velocity response spectra for three sites near the 2005 Kashmir earthquake for which site conditions were available (Okawa in Strong earthquake motion recordings during the Pakistan, 2005/10/8, Earthquake, 2005. https://iisee.kenken.go.jp ) are compared with observed spectra. This study provides a first-order ground motion database for safe design of buildings and other infrastructure in the NW Himalayan region.

Impact of Slab Thickness on Reinforced Concrete Buildings using Fragility Curves

Earthquakes are the natural disaster occurring since years but during the last two decades they are causing huge looses whether it may economic or to life. This paper focuses to evaluate the seismic performance of various building confirming to Indian standard criteria for earthquake resistant design of structures and ductile detailing of reinforced concrete structures subjected to seismic Forces-code of practice, Bureau of Indian Standards, both as per the revised codes in the year 2016. Due to ground shaking, seismic loads are the governing load and thus it becomes necessary to assess the conditional probability of structural response. Use of HAZUS methodology is followed to construct seismic fragility curves as it is well-organized and defined approach. Spectral displacement plays the functional parameter to derive the expected damage for fragility. This work represented here is compiled by means of procedure for establishing the fragility curves for three typical Reinforced Concrete (RC) frame structures having variations resembling 3 storey intended for short-period structures, 6 storey used for medium-period structures and 12 storey representing long-period structures using SAP2000 as a software tool for analyzing the structure. Furthermore an attempt is made for focus on the variation of one of the major structural configuration i.e. slab thickness which is not certainly paid attention as compared to columns and beams. Slabs adds additional stiffness to the structure which can enlighten how it behaviour would be when subjected to ground excitation. As a result, the fragility curves are plotted to study the impact due to slab thickness in order they are carefully selected while design.

Seismic hazard curves for Warangal city in Peninsular India

A site-specific probabilistic seismic hazard analysis (PSHA) has been carried out for the heritage city Warangal in Telangana state of Peninsular India. The Cornell–McGuire approach of PSHA has been considered to estimate the hazard. The area of influence is taken as 500 km radius. A homogeneous and updated earthquake catalogue was compiled for the considered area which was later categorized into four seismic sources (zones) considering the earthquake epicentre and geology. The seismic parameters a and b were estimated and the b value of the for the four seismic zones ranges from 0.72 to 0.97, whereas the a value ranges from 2.45 to 3.20. The results obtained are shown as uniform hazard curves and hazard maps showing the spatial variation peak ground acceleration (PGA) considering 2% and 10% probability of exceedance in 50 years. The PGA and PSA values were compared with NDMA (Development of probabilistic seismic hazard map of India, technical report of the Working Committee of Experts (WCE), National Disaster Management Authority (NDMA), Govt. of India, New Delhi, 2010) and IS 1893-1 (Criteria for earthquake resistant design of structures, part 1: general provisions and buildings, 6th edition, Bureau of Indian Standards, New Delhi, 2016). The study focussed on understanding the possibility of seismic hazard at the heritage city Warangal in Peninsular India.

Evaluation of Soil Structure Interaction Effect for Tanks under Earthquake with Different Foundations Soils

Though the structures are supported on soil, most of the designers do not consider the soil structure interaction and its subsequent effect on the structure during an earthquake. Different soil properties can affect seismic waves as they pass through a soil layer. When a structure is subjected to an earthquake excitation, it interacts with the foundation and soil, and thus changes the motion of the ground. It means that the movement of the whole ground structure system is influenced by type of soil as well as by the type of an engineering structure. Tanks are supposed to be of construction in sense that they might have been analyzed and designed to meet the provision of relevant codes of practice and building bye-laws. IS 1893: 2002 “Criteria for Earthquake Resistant Design of Structures” gives response spectrum for different types of soil such as hard, medium and soft. An attempt has been made in this paper to study the effect of Soil-structure interaction on multi storeyed buildings with various foundation systems as well as to study the response of buildings subjected to seismic forces with Rigid and Flexible foundations. Tanks with fixed and flexible support subjected to seismic forces were analysed under different soil conditions like hard, medium and soft. The buildings were analysed by Response spectrum method using software by ABAQUS program . A structural model using the generalized single degree of freedom (SDF) system is proposed for seismic design of concrete rectangular Liquid Containing Structures (LCS). The proposed model considers the effect of flexibility of tank wall on hydrodynamic pressures and uses the consistent mass approach. The proposed model is compared with the results obtained using the current practice as well as the finite element method. It is concluded that the current approach in design codes and standards does not truly represent the behaviour of LCS. The proposed model using the generalized SDF system can be simply used in seismic design of LCS.

Evaluation of soil-structure interaction for structures subjected to earthquake loading with different types of foundation

However though the structures are supported on soil, most of the designers do not consider the soil structure interaction and its subsequent effect on structure during an earthquake. Different soil properties can affect seismic waves as they pass through a soil layer. When a structure is subjected to an earthquake excitation, it interacts the foundation and soil, and thus changes the motion of the ground. It means that the movement of the whole ground structure system is influenced by type of soil as well as by the type of structure. Tall buildings are supposed to be of engineered construction in sense that they might have been analyzed and designed to meet the provision of relevant codes of practice and building bye-laws. IS 1893: 2002 “Criteria for Earthquake Resistant Design of Structures” gives response spectrum for different types of soil such as hard, medium and soft. An attempt has been made in this paper to study the effect of Soil-structure interaction on multi storeyed buildings with various foundation systems. Also to study the response of buildings subjected to seismic forces with Rigid and Flexible foundations. Multi storeyed buildings with fixed and flexible support subjected to seismic forces were analyzed under different soil conditions like hard, medium and soft. The buildings were analyzed by Response spectrum method using software SAP2000. The response of building frames such as Lateral deflection, Story drift, Base shear, Axial force and Column moment values for all building frames were presented in this paper.

Empirical Attenuation relationship for Peak Ground Horizontal Acceleration for North-East Himalaya

Empirical Attenuation relationship for Peak Ground Horizontal Acceleration for North-East Himalaya

Deterministic Seismic Hazard Analysis for the State of Haryana, India

The Indian state of Haryana is in a phase of rapid industrial development. In order to help engineers and town planners in designing earthquake resistant structures, it is necessary to carry out site specific seismic hazard analysis and plan mitigation measures. It is apprehended that Indian Code generalises the design peak ground acceleration values which may underestimate the seismic loading in high seismicity regions. Therefore, it is necessary to develop regional seismic hazard scenario in line with the local seismotectonic setting which is consistent with other seismic codes worldwide. In all, 12 seismogenic sources have been identified in the seismic study area. The maximum magnitude has been assigned to each seismogenic source considering regional rupture character. Ground motion prediction equation developed for Indo-Gangetic region by National Disaster Management Authority of India has been used. The peak ground acceleration along with response spectrum for A-type sites for the state have been estimated using state of the art in deterministic seismic hazard analysis methodology. These determined strong motion parameters have been compared with the values given in Indian Standard for criteria for earthquake resistant design of structures to validate them for further practical use. The prepared spectra can be further used to quantify seismic loading for designing earthquake resistant structures in Haryana.

Deterministic seismic hazard analysis considering different seismicity levels for the state of Goa, India

Deterministic seismic hazard analysis (DSHA) is carried out for the state of Goa, which is a small but one of the most popular touristic places on the west coast of peninsular India. Goa state is located about 250 km from Koyna region which experienced a 6.3 magnitude earthquake in 1967 and about 350 km from Latur which witnessed a 6.3 magnitude earthquake in 1993. Hence, it is important to carry out the seismic hazard analysis for Goa, such studies being scarce in literature till date. In this paper, DSHA for Goa is carried out by considering a 350 km distance from the state boundary taking into account the historic seismicity and identifying active faults and lineaments. Seven attenuation relationships developed for intraplate regions and shallow crustal earthquakes including one developed specifically for peninsular India are used. Three earthquake scenarios representing three levels of seismic activity are considered using the logic tree approach. The maximum magnitude estimated by empirical relations and the same from past earthquake events are considered in two scenarios for carrying out the DSHA, and the third scenario is derived from the previous two scenarios using equal weightage. The peak ground acceleration (PGA) values are obtained by considering a grid of 0.1° × 0.1° (i.e., 11.1 km × 11.1 km) covering the entire state of Goa. The deterministic seismic hazard map showing contours of PGA are developed for the state of Goa for the three scenarios. For the mildest scenario 2, highest hazard with PGA of 0.15 g is found at localized areas in the southwest of Goa. The hazard maps for the severe scenarios indicate high hazard in the central band of the state. The deterministic spectra are developed for five major cities of Goa and compared with the spectra given in Indian seismic code IS 1893-Part 1 (Criteria for Earthquake resistant design of structures. Bureau of Indian standards, New Delhi, 2002). PGA map and the spectra will be very useful for seismic design of important structures in Goa.

Dynamic Site Characterization and Correlation of Shear Wave Velocity with Standard Penetration Test ‘N’ Values for the City of Agartala, Tripura State, India

Seismic site characterization is the basic requirement for seismic microzonation and site response studies of an area. Site characterization helps to gauge the average dynamic properties of soil deposits and thus helps to evaluate the surface level response. This paper presents a seismic site characterization of Agartala city, the capital of Tripura state, in the northeast of India. Seismically, Agartala city is situated in the Bengal Basin zone which is classified as a highly active seismic zone, assigned by Indian seismic code BIS-1893, Indian Standard Criteria for Earthquake Resistant Design of Structures, Part-1 General Provisions and Buildings. According to the Bureau of Indian Standards, New Delhi (2002), it is the highest seismic level (zone-V) in the country. The city is very close to the Sylhet fault (Bangladesh) where two major earthquakes (M w > 7) have occurred in the past and affected severely this city and the whole of northeast India. In order to perform site response evaluation, a series of geophysical tests at 27 locations were conducted using the multichannel analysis of surface waves (MASW) technique, which is an advanced method for obtaining shear wave velocity (V s) profiles from in situ measurements. Similarly, standard penetration test (SPT-N) bore log data sets have been obtained from the Urban Development Department, Govt. of Tripura. In the collected data sets, out of 50 bore logs, 27 were selected which are close to the MASW test locations and used for further study. Both the data sets (V s profiles with depth and SPT-N bore log profiles) have been used to calculate the average shear wave velocity (V s30) and average SPT-N values for the upper 30 m depth of the subsurface soil profiles. These were used for site classification of the study area recommended by the National Earthquake Hazard Reduction Program (NEHRP) manual. The average V s30 and SPT-N classified the study area as seismic site class D and E categories, indicating that the city is susceptible to site effects and liquefaction. Further, the different data set combinations between V s and SPT-N (corrected and uncorrected) values have been used to develop site-specific correlation equations by statistical regression, as ‘V s’ is a function of SPT-N value (corrected and uncorrected), considered with or without depth. However, after considering the data set pairs, a probabilistic approach has also been presented to develop a correlation using a quantile–quantile (Q–Q) plot. A comparison has also been made with the well known published correlations (for all soils) available in the literature. The present correlations closely agree with the other equations, but, comparatively, the correlation of shear wave velocity with the variation of depth and uncorrected SPT-N values provides a more suitable predicting model. Also the Q–Q plot agrees with all the other equations. In the absence of in situ measurements, the present correlations could be used to measure V s profiles of the study area for site response studies.

Spatial variation of probabilistic seismic hazard for Mumbai and surrounding region

Mumbai city, the economical capital of India, is located on the west coast of stable intra-plate continental region of Peninsular India which has an experience of significant historical earthquakes in the past. The city stood as the fourth most populous city in the world. Recent seismo-tectonic studies of this city highlighted the presence of active West coast fault and Chiplun fault beneath the Deccan basalt. In the present study, spatial variability of probabilistic seismic hazard for Mumbai region (latitudes of 18.85–19.35°N and longitudes of 72.80–73.15°E at a grid spacing of 0.05°) which includes Mumbai city, Suburban, part of Thane district and Navi Mumbai, in terms of ground motion parameters; peak horizontal acceleration and spectral acceleration at 1.0-s period for 2 and 10 % probability of exceedance in 50 years are generated. The epistemic uncertainty in hazard estimation is accounted by employing seven different ground motion prediction equations developed for worldwide shallow crustal intra-plate environments. Further, the seismic hazard results are deaggregated for Mumbai (latitude 18.94°N, longitude 72.84°E) to understand the relative contributions of earthquake sources in terms of magnitude and distance. The generated hazard maps are compared with the zoning specified by Indian seismic code (IS1893: Part 1 in Indian standard criteria for earthquake-resistant design of structures, Part 1—General provisions and buildings. Bureau of Indian Standards, New Delhi, India, 2002) for rocky site. Present results show an underestimation of potential seismic hazard in the entire study region by non-probabilistic zoning prescribed by IS1893: Part 1 with significantly higher seismic hazard values in the southern part of Navi Mumbai.

Determination of Time Period of Vibration Effect on Seismic Performance of Building

Most seismic codes specify empirical formulas to obtain the fundamental period of buildings. The equations specified in present IS codes, are according to the available data on the time period of buildings measured from their recorded accelerograms. Shear-wall dominant reinforced concrete buildings, constructed, using codes specification are commonly built in different countries, facing a substantial seismic risk, in spite of their high resistance against ground motions. Current seismic code provisions including the Uniform Building Code (International Conference of Building Officials, Whittier, CA, 1997) and the Indian Seismic Code (Criteria for earthquake resistant design of buildings, fifth revision, 2002) are considered to evaluate the effect of time period on seismic behavior of building.In this study, time period obtained by code formulas are compared with those obtained by modal analysis in SAP2000. Also the top story displacement (as an adequate parameter of determination the seismic performance of building) correspond to the values of mentioned time period are estimated using uniform building code and software respectively. It is observed that current empirical equation for calculating the time period of RCC buildings is rather inaccurate. Also it is shown that the time period has very effective influence on seismic performance of building.

Evaluation of liquefaction potential hazard of Chennai city, India: using geological and geomorphological characteristics

According to the latest UNFA Report on state of world population 2007, unleashing the potential of urban growth by 2030, the urban population will rise to 5 billion or 60 % of the world population. Liquefaction in urban areas is dangerous phenomenon, which cause more damage to buildings and loss of human lives. Chennai, the capital city of the State Tamil Nadu in India, is one of the densely populated cities in the country. The city has experienced moderate magnitude earthquakes in the past and also categorized under moderate seismic hazard as per the Bureau of Indian Standards (BIS in Criteria for earthquake resistant design of structures; Bureau of Indian Standards, New Delhi, 1893 2001). A study has been carried out to evaluate the liquefaction potential of Chennai city using geological and geomorphological character- istics. The subsurface lithology and geomorphological maps were combined in the GIS plat- form for assessing the liquefaction potential. The liquefaction hazard broadly classified into three categories viz., liquefaction likely, possible and not likely areas. Mainly, the liquefaction likely areas spread along the coastal areas and around the river beds. The rest of the areas are liquefaction not likely and possible. The present map can be used as first-hand information on regional liquefaction potential for the city, and it will be help to the scientists, engineers and planners who are working for future site-specific studies of the city.

Thermally Developing Laminar Flow in a Duct with External Radiation and Convection

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