Ground Motion

Building damage level due to earthquake is widely related to the features of the record which consist of many parameters. Although it is difficult to realize the ground motion parameters that have high influence on building performance, the vital parameters that may cause building damage may be considered as PGA, PGV, PGD, PGA/PGV, PGA/PGD, PGV/PGD, frequency content, effective time duration, fault line distance of the earthquake. In this study, these parameters were selected in order to determine more effective parameter on the building performance. For this aim, a model of Artificial Neural Network (ANN) algorithm was used as an efficient tool consisting of the obtained results of nonlinear time history analysis of samples. The 200 records, produced by strike-slip fault mechanism, were selected for the soil type C (Z3) according to the Turkish Earthquake Code [1]. A six story R/C frame building, with three various spans were analyzed via IDARC-2D software. The Park and Ang damage index was used in order to evaluate the vulnerability of buildings. The results showed that the ANN can be able to determine the effective parameters of ground motions with sufficient correlation. Also the most and least significant parameters of earthquake are discussed based on the results of the analysis.

In this paper, a performance-based seismic design procedure, which is directly associated with pre-quantified performance criteria, is presented by employing a displacement-based approach. A lower bound of yielding displacement of the structure to satisfy these performance criteria is proposed. The approach is general in employing either equivalent elastic or inelastic response spectrum. Non-linear time history analysis verified that this approach is applicable to control the target displacement to the performance acceptable limit. Its flexibility in considering special effect such as near-fault or strong motion duration and simplicity in a proposed multiple performance objectives design are demonstrated.

The objective of this work is to test whether an empirical Ground Motion Model (GMM) developed for high-seismicity regions can be effectively adapted to a neighbouring region with lower seismic activity. We select the ITA18 suite of GMMs (Lanzano et al. in Bull Seismol Soc Am 109(2): 525-540, 2019a), developed for Italy, which is a region dominated by moderate-to-strong shallow crustal earthquakes, and assess their applicability to Continental France, where the seismic activity is less frequent and characterised by lower magnitudes. Based on a dataset of more than 2300 records of events with 3.0 ≤ M W ≤ 5.2, occurred in France in the time interval 1996-2019 (named FR20), we perform a residual analysis and calibrate an adjustment factor for both horizontal and vertical-to-horizontal (VH) components of Peak Ground Acceleration, Peak Ground Velocity, and 5% damped Spectral Acceleration (SA). Apart from the median correction, no modification of the scaling with magnitude, focal mechanism, and V S,30 is introduced, while the distance scaling is adjusted to capture the lower anelastic attenuation of the French data. In addition, to overcome the underestimation of the ITA18 model for the short period VH spectral amplitudes in the near-source region (R epi < 15 km), an additional empirical corrective factor is introduced. In spite of the good agreement of the adjusted model with respect to the median trends of the FR20 dataset, a regionalization of the source effects is introduced to reduce the relatively high between-event variability of the proposed model. The proposed model provides predictions similar to ITA18 in the most seismically active regions (Alps or Pyrenees), while, in the other zones, the predicted amplitudes are richer at high frequencies. Given the paucity of seismic records in these zones, this behavior should be confirmed on the basis of additional data (e.g. physics-based simulations, geologic and tectonic features). The use of the proposed model for hazard applications is recommended within the validity limits of the data (3.0 ≤ M W ≤ 5.2). However, the similarity of the ground motion in the Alps and Pyrenees with the predictions of ITA18 suggests that the adjusted model could be also employed for higher magnitudes, upon suitable checks.

New performance-based earthquake engineering methods developed by the Pacific Earthquake Engineering Research Center, the Applied Technology Council, and others include damage analysis at a highly detailed level, requiring the compilation of fragility functions for a large number of damageable generic structural and nonstructural components. This brief paper presents the development of a fragility function for hydraulic elevators. It uses post-earthquake survey data from 91 elevators in nine California locations after two earthquakes. Surveys were used to collect data on facilities and elevators. Ground-motion records from the California Integrated Seismic Network were used to estimate engineering demands at each site. Binary regression analysis was used to fit a fragility function, which takes the form of a lognormal cumulative distribution function with median value of PGA=0.42 g and logarithmic standard deviation of 0.3. The fragility function appears to be reasonable based on fo...

C onstruction industry consumes a lot of mineral resources and is the most energy intensive sector. In addition, it is responsible for a high percentage of green house gas emissions and hence has large environmental impact. The use of recycled concrete aggregates from rubble and demolition waste in combination with cementitious additions could contribute to an environment friendly construction by reducing CO 2 emissions and reducing the consumption of natural resources. In this paper, the performance at the fresh and hardened state of an eco-concrete (ordinary and self compacting) made of recycled concrete aggregates and either natural pouzzolana or granulated blast furnace slag is discussed. Natural aggregates were either partially or fully substituted by recycled aggregates and cement was partially substituted by either natural pouzzolana or slag. The results showed that an ordinary recycled aggregates concrete with comparable mechanical properties and durability to natural aggregates concrete could be produced. The use of recycled aggregates gives a self compacting concrete with comparable rheological properties to that of control concrete. The substitution of cement by natural pouzzolana decreases the workability of the control concrete whereas the use of slag improves it. However, an improvement has been noted for SCC made with recycled concrete aggregates. Said Kenai is a Professor and Chairman of the Civil Engineering Research Laboratory at the University of Bilda, Algeria. He obtained his PhD from Leeds University (England) in 1988. His main interests include building materials, concrete technology, cement replacement materials, durability, non destructive testing and repair of concrete structures. He has published more than 50 papers in international journals and is serving as an Editorial Board Member of many reputed journals. He is also member of RILEM TC-ISC technical committee.

Particle accelerators pushed the limits of our knowledge in search of the answers to most fundamental questions about micro-world and our Universe. In these pursuits, accelerators progressed to higher and higher energies and particle beam intensities as well as increasingly smaller and smaller beam sizes. As the result, modern existing and planned energy frontier accelerators demand very tight tolerances on alignment and stability of their elements: magnets, accelerating cavities, vacuum chambers, etc. In this article we describe the instruments developed for and used in such accelerators as Fermilab's Tevatron (FNAL, Batavia, IL USA) and for the studies toward an International Linear Collider (ILC). The instrumentation includes Hydrostatic Level Sensors (HLS) for very low frequency measurements. We present design features of the sensors, outline their technical parameters, describe test and calibration procedures and discuss different regimes of operation. Experimental results of the ground motion measurements with these detectors will be presented in subsequent paper.

Dynamic effects on an arch dam should be taken into account together with gravity and hydrostatic pressure for the most critical conditions. This study presents three-dimensional linear earthquake response of an arch dam. Different soil parameters and ground motion accelerograms are used in the finite element analyses. The Type 3 double curvature of an arch dam which is one of the five type models suggested in Arch Dams Symposium organized in England in 1968 is considered in this paper. All numerical analyses are carried out by SAP2000 program for empty reservoir case. In the scope of this study, modal analyses and modal timehistory analyses are performed using three dimensional finite element model of the arch dam and arch dam-foundation interaction systems. According to numerical analyses, maximum horizontal displacements and principle stresses are shown by height and also evaluated earthquake for various soil conditions and earthquakes. Besides this study clearly appears that the...

Dynamic effects on an arch dam should be taken into account for the ground motions. This study presents threedimensional linear earthquake response of an arch dam. Different ground motion effects and besides rigid and elastic foundation conditions are considered in the finite element analyses. For this purpose, the Type 3 double curvature arch dam was selected due to numerical solutions. All numerical analyses are carried out by SAP2000 V.17 program for empty reservoir case. In the scope of this study, linear modal time-history analyses are performed using three dimensional finite element model of the arch dam and arch dam-foundation interaction systems. Furthermore, near-fault and far field ground motion effects on the selected arch dam were taken into account by different accelerograms obtained from the Loma Prieta earthquake at various distances. According to numerical analyses, maximum horizontal displacements and maximum normal stresses are presented by height and these are eva...

We describe the main structure and outcomes of the new probabilistic seismic hazard model for Italy, MPS19 [Modello di Pericolosità Sismica, 2019]. Besides to outline the probabilistic framework adopted, the multitude of new data that have been made available after the preparation of the previous MPS04, and the set of earthquake rate and ground motion models used, we give particular emphasis to the main novelties of the modeling and the MPS19 outcomes. Specifically, we (i) introduce a novel approach to estimate and to visualize the epistemic uncertainty over the whole country; (ii) assign weights to each model components (earthquake rate and ground motion models) according to a quantitative testing phase and structured experts’ elicitation sessions; (iii) test (retrospectively) the MPS19 outcomes with the horizontal peak ground acceleration observed in the last decades, and the macroseismic intensities of the last centuries; (iv) introduce a pioneering approach to build MPS19_clust...

Earthquakes are disastrous to mankind. It affects human life, buildings and economy. Overcoming the after effects of earthquakes & diseases all imposes challenges to human life. All these can be minimised if early detection & warning of an earthquake is sent to areas where possibility of occurrence of earthquake is most predominant.

This paper employs three-dimensional parallel finite elements to assess the seismic response and resilience of various pile group configurations. The numerical model was verified in the literature through two large-scale shaking table tests. A parametric study was conducted to depict the influences of pile number (N), position within a pile group, pile nonlinearity, and frequency content on the seismic response in sloping liquefiable soils. The result showed that the importance of these factors on the analysis and design for the pile groups, while they are not considered in the current design codes including Japan Road Association (JRA) 2002 and American Petroleum Institute (API). Furthermore, the API method most likely underestimates P-y at shallow depths rather than numerical analysis results, while it overestimates at deeper burial depths. In addition, JRA code overestimates the monotonic soil pressure in the infinite pile group and underestimates it in the finite pile group. In other words, the difference between the computed soil pressure from JRA and the numerical model decreases with N. The asymmetry ratio (AR) is also important for the acceleration response, since AR decreases with N. Also, it has been shown that the seismic responses increase in corner piles with the N due to the increasing stiffness. Subsidence at the downslope side of the pile group and heave at the upslope side of the one occurs and increases with N. Nonlinear pile behavior increases maximum displacements, especially in central piles, while reducing internal forces in corner piles. Corner and side piles yield earlier, requiring middle piles to sustain greater forces under continued lateral spreading.

Site response analysis, namely the analysis of the wave propagation of shear waves through a soil deposit, requires the specification of the input ground motion and the dynamic characterization of the soil deposit. While the stochastic approach is commonly used for modelling seismic excitation, the use of probability density functions for describing the soil properties is consistent only when precise informations based on a large amount of data from soil surveys are available. Conversely, a non-probabilistic approach based on fuzzy set theory would be more appropriate for dealing with uncertainties that are just expressed by vague, imprecise, qualitative, or incomplete information and supplied by engineering judgement. In this paper, a hybrid fuzzy-stochastic 1D site response analysis approach for dealing with soil uncertainties defined as convex normal fuzzy sets is addressed. Zadeh's extension principle, in combination with an efficient implementation of the Differential Evolution Algorithm is used for global minimization and maximization. Results are presented as fuzzy median value of the largest peaks of the peak ground acceleration at the surface by considering four types of soil classified in accordance with the European seismic building code.

Predicting the usability of a building, i.e. its condition of being occupiable after a seismic event, is relevant both in a postemergency situation and within a risk-reduction policy. In the past an empirical model was proposed, involving the computation of a usability index based on macroseismic intensity and on seven building parameters, combined by means of regression coefficients and weights. The statistical model was calibrated on data of about 60 000 buildings affected by the 2009 L'Aquila earthquake in Italy. Therefore, it is useful to validate the model against data from the 2002 Molise earthquake in Italy. Good agreement between predicted and observed usability is shown, despite the fact that in 2002, macroseismic intensity was attributed to an entire municipality instead of a more limited area. Moreover, given the current availability of the shakemaps for the 2009 event, a novel model replacing conventional macroseismic intensity by an instrumental intensity measure is proposed. Three ground motion parameters are considered here: peak ground acceleration, peak ground velocity, and spectral pseudoacceleration at a period of vibration of 0.3 s. The model has been streamlined by reducing the building parameters from seven to five: building position within the structural aggregate, roof type, construction timespan, structural class, and pre-existing damage to structural elements. Peak ground acceleration and spectral pseudoacceleration are shown to be less effective than peak ground velocity in predicting observed usability. Therefore, usability probability matrices are computed in terms of peak ground velocity; the model is presented with all necessary coefficients and weights, and a worked-out example shows how to apply the procedure.

Hypnosis Treatment for Mental Illness in Colonial Bengal

During the colonial period in Bengal, hypnosis emerged as an experimental yet controversial method for treating mental illness. Influenced by European scientific and medical discourses, British psychiatrists and Indian medical practitioners explored hypnosis as part of a broader attempt to modernize psychiatric care. The introduction of hypnosis in mental asylums and private medical practices reflected a fusion of Western medical theories with indigenous healing traditions. Hypnosis, rooted in mesmerism and later refined by figures like James Braid, was perceived as a technique to access and influence the unconscious mind. British doctors in Bengal experimented with it to treat hysteria, melancholia, and other nervous disorders, often linking such conditions to the stresses of colonial modernity. At the same time, Indian practitioners, particularly those familiar with yogic and tantric traditions, found parallels between hypnosis and indigenous trance-based healing methods.

However, the use of hypnosis was not widely institutionalized, partly due to skepticism from the colonial medical establishment. Many British psychiatrists viewed it as unreliable compared to emerging somatic treatments like moral therapy, diet regulation, and pharmacological interventions. Moreover, hypnosis sometimes intersected with spiritual and religious practices, making it suspect in the eyes of colonial authorities who sought to separate Western medicine from "native superstition." Despite its marginalization, hypnosis in colonial Bengal remains a fascinating case study of how Western and indigenous medical traditions interacted under colonial rule. It highlights the complexities of psychiatric treatment in the colonial context, where power dynamics, cultural exchanges, and scientific debates shaped the evolution of mental health care.

A new stochastic methodology for the generation of artificial, fully non-stationary, and spectrumcompatible seismic accelerograms is proposed. The model operates in the time-frequency (TF) domain and combines spectral representation techniques with signal processing operations. More specifically, a zero mean stationary Gaussian stochastic process is generated using the spectral representation method. This component models the target peak ground acceleration, the frequency range, and the phase distribution of the artificial accelerogram. Additionally, it ensures the compatibility of the accelerogram with a target spectrum through the power spectral density function of the process. The signal is then analyzed in the TF domain using the continuous wavelet transform (CWT). A TF modulating function modifies the obtained wavelet coefficients, in order to model the temporal and spectral non-stationarity. The TF envelope function is modeled after a historical accelerogram and is obtained from the modulus of the CWT coefficients of the recorded accelerogram. Spectral energy distribution compatibility is also imposed at each frequency, and new wavelet coefficients are produced. The simulated signal is then transformed in the time domain using the inverse CWT. The proposed methodology provides an arbitrary number of seismic accelerograms whose temporal and spectral modulation is consistent with the site of interest. The model is also extended to generate suites of artificial accelerograms that are compatible with a seismic hazard scenario, either in the form of a uniform hazard spectrum, or from a ground motion model.

Within the last decade, the number of earthquake events in Northern Thailand has significantly increased. At least, two major earthquakes have occurred in this region: the 2011 M w 6.8 Tarlay Earthquake and the 2014 M w 6.3 Mae Lao Earthquake. The lack of understanding on appropriate attenuation models to represent a specific region becomes a major issue if strong ground motion data is not available. This paper aims to determine an appropriate attenuation model for Northern Thailand based on seven recorded earthquake events in the region. Nine attenuation models, including ground motion prediction equations (GMPEs) from both NGA-West1 and NGA-West2 (Next Generation Attenuation Relationships for Western US), were employed to predict peak ground acceleration (PGA) and spectral acceleration (SA) during the selected earthquake events. Ground motion data during the events from twenty nearby seismic stations were collected for verifying the predictions from each attenuation model. Goodness of fit test and root mean square error (RMSE) were evaluated for each attenuation model prediction. The results show that the NGA-West2 are the most appropriate attenuation models to predict ground motion in Northern Thailand. As a consequence of verifying these attenuation models, it is hoped that further development of Thailand's seismic design standards for seismic hazard analysis of specific regions such as Northern Thailand can be based on more accurate, appropriately selected models.

Within the last decade, the number of earthquake events in Northern Thailand has significantly increased. At least, two major earthquakes have occurred in this region: the 2011 M w 6.8 Tarlay Earthquake and the 2014 M w 6.3 Mae Lao Earthquake. The lack of understanding on appropriate attenuation models to represent a specific region becomes a major issue if strong ground motion data is not available. This paper aims to determine an appropriate attenuation model for Northern Thailand based on seven recorded earthquake events in the region. Nine attenuation models, including ground motion prediction equations (GMPEs) from both NGA-West1 and NGA-West2 (Next Generation Attenuation Relationships for Western US), were employed to predict peak ground acceleration (PGA) and spectral acceleration (SA) during the selected earthquake events. Ground motion data during the events from twenty nearby seismic stations were collected for verifying the predictions from each attenuation model. Goodness of fit test and root mean square error (RMSE) were evaluated for each attenuation model prediction. The results show that the NGA-West2 are the most appropriate attenuation models to predict ground motion in Northern Thailand. As a consequence of verifying these attenuation models, it is hoped that further development of Thailand's seismic design standards for seismic hazard analysis of specific regions such as Northern Thailand can be based on more accurate, appropriately selected models.

This article highlights the implication of site-specific properties on seismic ground response studies. One-dimensional equivalent linear ground response analysis was carried out using site-specific dynamic properties of locally available soils of Guwahati city, and the results are compared with those obtained using existing strain-dependent dynamic properties. Acceleration time histories from three strong motions were used. It was observed that an input motion having a higher peak bedrock acceleration, utilizing experimentally obtained dynamic soil properties, exhibits 38% and 24% lower peak ground acceleration and peak spectral acceleration, respectively, in comparison to the results obtained using standard VD-SI soil models. The amplification characteristics of the strong motions are observed to be significantly influenced by the degradation of damping ratio beyond 1% shear strain. The results highlight the necessity of conducting GRA of any region considering its regional dynami...

In this study, one dimensional equivalent–linear ground response analyses were performed for some typical sites in the Guwahati city, India. Six bore locations covering about 250 km2 area of the city were considered for the analyses. As the strong motion significantly influences the ground response, seven different recorded ground motions, varying in magnitude (6.1 to 8.1) and other ground motion parameters, were adopted. Seismic site analyses were carried out for all layers of borelogs using all the seven earthquakes. Results are presented in terms of surface acceleration histories, strain and shear stress ratio variation, response spectrum, Fourier amplitude ratio versus frequency. The results indicate that accelerations were amplified the most at the surface level. The range of peak ground acceleration (PGA) values obtained at the ground surface is about 0.2 g to 0.79 for a range of PGA considered at bedrock level (rigid half space at bottom of borelog) of 0.1 g to 0.34 g. The Fo...

We consider, using theory and associated synthetic seismograms, the seismic response of a site comprising a horizontal, homogeneous, soft viscoelastic layer of infinite lateral extent overlying, and in welded contact with, a homogeneous, hard elastic substratum of half-infinite radial extent. We show that for shear-horizontal motion: (1) coupling to Love modes is all the weaker the deeper the source (modelled as a line, assumed to lie in the substratum) is from the lower boundary of the soft layer, (2) for a line source close to the lower boundary of the soft layer, the ground response is characterized by possible beating phenomena, and is of significantly longer duration than for excitation by cylindrical waves radiated by deep sources. Numerical applications of the theory show, for instance, that a line source, located 40 m below the lower boundary of a 60-m-thick soft layer in a hypothetical Mexico-City-like site, radiating a SH pulse of 4 s duration, produces substantial ground motion during 200 s, with marked beating, at an epicentral distance of 3 km. Results from this modelling study are supported by field examples taken from published literature.

The double impulse input is introduced as a substitute of the fling-step near-fault ground motion and a closed-form solution of the elastic-plastic response of a structure by the "critical double impulse input" is derived. Since only the free-vibration appears under such double impulse input, the energy approach plays an important role in the derivation of the closed-form solution of a complicated elastic-plastic response. It is shown that the maximum inelastic deformation can occur either after the first impulse or after the second impulse depending on the input level. The validity and accuracy of the proposed theory are investigated through the comparison with the response analysis to the corresponding one-cycle sinusoidal input as a representative of the fling-step near-fault ground motion. Since the critical input means the resonant case, the present theory dealing with the resonant response should be applied to buildings except very flexible ones.

Earthquakes are disastrous to mankind. It affects human life, buildings and economy. Overcoming the after effects of earthquakes & diseases all imposes challenges to human life. All these can be minimised if early detection & warning of an earthquake is sent to areas where possibility of occurrence of earthquake is most predominant.

Between the late nineteenth century and the early twentieth century, Barcelona was expanded, occupying the terrains connecting the old walled city and the nearby towns of the plateau of Barcelona. At that time, a large number of unreinforced masonry buildings were constructed and nowadays many of them are still used as dwellings. Though built individually, these buildings are connected to adjacent buildings, forming blocks composed of aggregates. In order to analyze the seismic behavior of isolated buildings and aggregates, two typical central buildings and one typical corner building have been chosen. The two central buildings and the corner building are referred as C1, C2, and E buildings. Two corner buildings and two central buildings have been connected in order to simulate a block side. This aggregate is referred as AGG and it is composed by the following sequence of individual buildings: E-C1-C2-E. Original plans and drawings of existing buildings are then used to model these buildings. The modeled buildings have five stories. Standard pushover analyses lead to evaluate their seismic performance by means of capacity spectra and fragility curves. The analysis has been carried out in the parallel (Ux) and transversal (Uy) directions to the street. Then, a capacity spectrum based method is used to analyze the seismic behavior of these buildings considered as individual buildings and as an aggregate. Two earthquake scenarios are considered. The first one is a deterministic scenario which is based on a historical earthquake occurred in 1824, 25 km away from the city and the second one is a probabilistic scenario, which represents the ground motion with a probability of occurrence of 10% in 50 years. The soil local effects have been also considered and both scenarios have been used to assess the expected damage. Four non-null damage states are considered: slight (1), moderate (2), severe (3) and extensive-to-collapse (4). For the type of soil where most of the buildings are, and in the Ux direction, the four buildings show a similar behavior. The mean damage grade is 2.3 for the deterministic scenario and 2.7 for the probabilistic one. This means that moderate to severe damage is expected in both cases; furthermore, in the case of the deterministic scenario more than 10% of the buildings would suffer extensive-to-collapse damage and nearly 20% for the probabilistic scenario, confirming the high vulnerability of such buildings. The differences in the expected damage are due to the significant different characteristics of the response spectra of the earthquake scenarios in the range of the fundamental periods of the buildings.

This paper investigates variability in bobbing and jumping actions, including variations within a population of eight test subjects (intersubject variability) and variability on a cycle-by-cycle basis for each individual (intrasubject variability). A motion-capture system and a force plate were employed to characterize the peak ground reaction force, frequency of the activity, range of body movement, and dynamic loading factors for at least first three harmonics. In addition, contact ratios were also measured for jumping activity. It is confirmed that most parameters are frequency dependent and vary significantly between individuals. Moreover, the study provides a rare insight into intrasubject variations, revealing that it is more difficult to perform bobbing in a consistent way. The paper demonstrates that the vibration response of a structure is sensitive to cycle-by-cycle variations in the forcing parameters, with highest sensitivity to variations in the activity frequency. In addition, this paper investigates whether accurate monitoring of the ground reaction force is possible by recording the kinematics of a single point on the human body. It is concluded that monitoring the C7th vertebrae at the base of the neck is appropriate for recording frequency content of up to 4 Hz for bobbing and 5 Hz for jumping. The results from this study are expected to contribute to the development of stochastic models of human actions on assembly structures. The proposed simplified measurements of the forcing function have potential to be used for monitoring groups and crowds of people on structures that host sports and music events and characterizing human-structure and human-human interaction effects.

The city of Sofia is exposed to a high seismidc risk. Macroseismic intensities in the range of VIII -X (MSK) can be expected in the city. The earthquakes, that can influence the hazard at Sofia, originate either beneath the city or are caused by seisnmic sources located within a radius of 40km. The city of Sofia is also prone to the remote Vrancea seismic zone in Romania, and particularly vulnerable are the longperiod elements of the built environment. The high seism-ic risk and the lack of instrumental recordings of the regional seismicity makes the use of appropriate credible earthquake scenarios and ground motion modelling approaches for defining the seismic input for the city of Sofia necessary. Complete synthetic seismic signals, due to several earthquake scenarios, were computed along chosen geological profiles crossing the city, applying a hybrid technique, based on the modal summation technique and finite differences. The modelling takes into account simultaneously the geotechnical properties of the site, the position and geometry of the seismic source and the mechanical properties of the propagation medium. Acceleration, velocity and displacement time histories and related quantities of earthquake engineering interest (e.g. response spectra, ground motion amplification along the profiles) have been supplied. The approach applied in this study allows us to obtain the definition of the seismic input at low cost exploiting large quantities of existing data (e.g. geotechnical, geological, seismological). It may be efficiently used to estimate the ground motion for the purposes of microzonation, urban planning, retrofitting or insurance of the built environment, etc.

Elastomeric bearings are one of the most commonly used seismic isolators, whose considerably grown number of applications in recent years witnesses the confidence in seismic isolation. On the other hand, full-scale experimentation of isolators, so far conducted in a limited number of international facilities, focused the attention to unexpected collapses, highlighting how the assessment of the seismic behavior of base-isolated structures strongly depends on the accuracy of the isolators modeling. With some exception, models present in literature are generally intended to represent the overall isolator behavior, without information on the state of internal layers, where some rubber layer may show high deformations that can unevenly damage the layer itself and influence the global stress distribution. The main objective of the present work is to develop a phenomenological model able to represent the force-deformation state of each layer of the device. The proposed model includes geome...

The effects of the axial load variations on the seismic response of bridges isolated with friction pendulum systems (FPS) are investigated. A series of parametric time history non-linear analyses are performed for different bridge configurations, defined after an extensive investigation on typical existing cases. The influence of both horizontal and vertical components of the ground motion is considered. The behaviour of the pierisolator-deck system is predicted using two analytical models characterised by hysteretic loops sensitive or insensitive to axial force variations, in order to compare the different responses. Level of axial force, maximum displacements and induced bending moment are investigated, as well as shear and torsion demand, caused by different shear actions acting on the isolator devices. A comparison between demand and resistance capacity of the bridge piers is performed, in order to investigate possible non-conservative approaches in the current design methods and to raise controversial issues on the subject.

To better estimate the seismic ground motion during the April 6th, 2009 earthquake in L'Aquila, we deployed temporary arrays in the near-source region. Several arrays have been successively set up in the Aterno valley's epicentral area and have recorded the aftershocks that followed the main shock, between April and September. The data has been processed in order to study the spectral ratios of the horizontal component of ground motion at the soil site and at a reference site, as well as the spectral ratio of the horizontal and the vertical movement at a single recording site. The results obtained confirm the presence of large amplification effects in both L'Aquila's historic centre and in the suburban areas. The resonance frequency has been found to be close to 0.6 Hz in downtown L'Aquila whereas the suburban areas show amplification at frequencies ranging from 2 Hz to 5 Hz.

Incremental Dynamic Analysis (IDA) is a powerful method for evaluating the seismic performance of structural systems. When undertaking IDA, ground motion records are scaled in accordance with a certain seismic intensity level up until the limit of collapse of the structure is reached. Peak ground acceleration (PGA) is often used as intensity measure (IM) for scaling purposes whilst peak ground velocity and response spectral accelerations can also be used as IM parameters. One of the challenges with the IDA methodology is that the performance (IDA) curve obtained for a structural system is non-unique meaning that it can be sensitive to changes in the frequency properties of the input excitations. Thus, there is a practice of holding the frequency content of the excitation unchanged (or constrained to a model design spectrum) when applying the scaling. The shortcomings with this modelling approach is that real conditions can be misrepresented given that frequency contents of the earth...

Many seismologists have looked at the 26 January 2001 Bhuj earthquake as a key modern calibration event that could be used to improve estimates of magnitudes of large historic mainshocks in stable continental regions. Since no instrumental data are available for important historic events such as the 1819 Allah Bund, India, and the 1811-1812 New Madrid, central U.S. mainshocks, calibration hinges on comparisons of the macroseismic effects of these earthquakes with those of comparable modern earthquakes for which a reliable, instrumentally determined moment magnitude is available. However, although such a comparison is conceptually straightforward, in practice it is complicated by potentially significant inconsistencies in methods used to quantify macroseismic effects in different regions and/ or times. For the Bhuj earthquake, extensive intensity data sets have been compiled and published from both media accounts and detailed direct surveys. Comparing the two provides a quantification of the previously suspected media bias, whereby earthquake effects can be exaggerated in media accounts. This bias is a strong function of intensity level, with substantial bias at the highest shaking levels and significantly less bias at low intensities. Because only sparse documentary data are in general available for older historic earthquakes, the results of this study suggest that their inferred intensity distributions might be similarly biased. We further use the surveybased intensity values to develop a new relationship between intensities and ground motions.

We developed a Real-time Online earthquake Simulation system (ROS) to simulate regional earthquakes in Taiwan. The ROS uses a centroid moment tensor solution of seismic events from a Real-time Moment Tensor monitoring system (RMT), which provides all the point source parameters including the event origin time, hypocentral location, moment magnitude and focal mechanism within 2 min after the occurrence of an earthquake. Then, all of the source parameters are automatically forwarded to the ROS to perform an earthquake simulation, which is based on a spectral-element method (SEM). A new islandwide, high resolution SEM mesh model is developed for the whole Taiwan in this study. We have improved SEM mesh quality by introducing a thin high-resolution mesh layer near the surface to accommodate steep and rapidly varying topography. The mesh for the shallow sedimentary basin is adjusted to reflect its complex geometry and sharp lateral velocity contrasts. The grid resolution at the surface is about 545 m, which is sufficient to resolve topography and tomography data for simulations accurate up to 1.0 Hz. The ROS is also an infrastructural service, making online earthquake simulation feasible. Users can conduct their own earthquake simulation by providing a set of source parameters through the ROS webpage. For visualization, a ShakeMovie and ShakeMap are produced during the simulation. The time needed for one event is roughly 3 min for a 70 s ground motion simulation. The ROS is operated online at the Institute of Earth Sciences, Academia Sinica (). Our long-term goal for the ROS system is to contribute to public earth science outreach and to realize seismic ground motion prediction in real-time.

In conjunction with site-specific studies, probabilistic seismic hazard assessment (PSHA) is crucial in formulating site-specific response spectra to provide valuable insights into local seismic hazard variations. A site-specific seismic hazard assessment is presented considering a classical probabilistic approach incorporating ground response analysis for Assam, North-East (NE) India. NE India Region is classified into ten seismic source zones depending on the seismicity and tectonics. An updated homogenized earthquake catalogue for 1897-2022 has been used. The seismicity parameters have been calculated with the complete catalogue for each source zone. A topography-based Vs30 model has been considered, and for the application of ground motion prediction equations (GMPEs), a logic tree approach using the log-likelihood method (LLH) has been considered. The hazard maps for Assam are prepared at the bedrock level in terms of peak ground acceleration (PGA) and spectral acceleration (Sa) values. The PGA values vary between 0.23-0.34 g and 0.33-0.51 g for 475 and 2475 years of return period, respectively. The hazard curves and uniform hazard spectra (UHS) have also been presented for ten headquarters of Assam, along with disaggregation studies for Guwahati. Further, borehole data from Guwahati have been considered for evaluating ground responses with the assignment of proper soil conditions. The surface level PGA for Guwahati gets amplified significantly up to 0.41 g and 0.56 g for 475 and 2475 years of return period, respectively. Finally, the surface-level responses have been presented for Guwahati city, one of the ten headquarters of Assam, considering the controlling earthquake. Keywords Site-specific seismic hazard; Probabilistic approach; LLH; Assam; Guwahati; Ground response analysis The authors thank the Ministry of Human Resources (MHRD) for financial support. The authors also thank the websites such as USGS (United States Geological Survey), GCMT (Global Centroid Moment Tensor Catalog), NCS (National Center for Seismology), ISC (International Seismological Centre), PEER (Pacific Earthquake Engineering Research Center) Ground Motion Database, etc., for providing the valuable data required for the earthquake catalogue treatment and digital mapping. The Department of Science and Technology (DST) is also acknowledged for proving the micro-zonation atlas for the site of interest. The authors thank the software packages, such as OpenQuake, ArcGIS, MATLAB, and SeismoMatch, for offering a convenient analysis platform. Also, the authors are grateful to Andrzej Kijko and Stefan Wiemer for providing the codes (Kijko HA3 and ZMAP, respectively) for the computation of seismicity parameters.

This paper presents SEISM-HOME (SElection of Input Strong Motion for HOmogeneous MEgazone), an interactive application created to support non-expert users to automatically define the seismic input required to carry out dynamic analyses of structures and/or geotechnical systems, at any desired site of the Italian territory, by simply specifying the geographical coordinates. The methodology upon which SEISM-HOME has been developed is based on implementing four main steps: sorting all the response spectra of the Italian territory in 40 homogeneous groups; defining a reference (parent) response spectrum for each group; selecting spectrumcompatible accelerograms using the parent response spectrum of each group; linearly scaling the accelerograms to satisfy spectrum-compatibility with respect to other response spectra of the group. SEISM-HOME is freelyavailable at www.eucentre.it/seismhome.html and it allows the user to select a set of 7 spectrum-compatible real accelerograms compliant with the requirements of the Italian building code for rocky sites (475 years return period).

For the time lapse study in CCS and EOR, we have proposed the method using the seismic ACROSS (Accurately Controlled and Routinely Operated Signal System) and geophone array. However, it is considered that the near-surface effects and their temporal changes caused by water content changes, temperature and surface wave generation, might have very large effects for time lapse estimation, and we would like to evaluate and reduce the near-surface effects by the comparison of surface and borehole geophone records. We have carried out simulation studies to evaluate the effects of near-surface and heterogeneities such as the man-made cavities in the green tuff layers (Vp ̃2.5 km/s). We also evaluate the near-surface effects by changing geophone depths. The results of the simulations are as follows. At the simulation of surface hypocenters, seismic waves passed through the man-made cavities attenuated and seismic waves scattered at the man-made cavities. This shows that there will be a hete...

Complex finite-faulting source processes have important consequences for near-source ground motions, but empirical ground-motion prediction equations still lack near-source data and hence cannot fully capture near-fault shaking effects. Using a simulation-based approach, we study the effects of specific source parameterizations on near-field ground motions where empirical data are limited. Here, we investigate the effects of fault listricity through near-field kinematic ground-motion simulations. Listric faults are defined as curved faults in which dip decreases with depth, resulting in a concave upward profile. The listric profiles used in this article are built by applying a specific shape function and varying the initial dip and the degree of listricity. Furthermore, we consider variable rupture speed and slip distribution to generate ensembles of kinematic source models. These ensembles are then used in a generalized 3D finite-difference method to compute synthetic seismograms; the corresponding shaking levels are then compared in terms of peak ground velocities (PGVs) to quantify the effects of breaking fault planarity. Our results show two general features: (1) as listricity increases, the PGVs decrease on the footwall and increase on the hanging wall, and (2) constructive interference of seismic waves emanated from the listric fault causes PGVs over two times higher than those observed for the planar fault. Our results are relevant for seismic hazard assessment for near-fault areas for which observations are scarce, such as in the listric Campotosto fault (Italy) located in an active seismic area under a dam. Electronic Supplement: Movie of wave propagation for planar and listric faults.

This article investigates different approaches for assessing the degree of roughness of the slip distribution of future earthquakes. First, we analyze a database of slip images extracted from a suite of 152 finite-source rupture models from 80 events (M w = 4.1-8.9). This results in an empirical model defining the distribution of the slip spectrum corner wave numbers (k c ) as a function of moment magnitude. To reduce the "epistemic" uncertainty, we select a single slip model per event and screen out poorly resolved models. The number of remaining models (30) is thus rather small. In addition, the robustness of the empirical model rests on a reliable estimation of k c by kinematic inversion methods. We address this issue by performing tests on synthetic data with a frequency domain inversion method. These tests reveal that due to smoothing constraints used to stabilize the inversion process, k c tends to be underestimated. We then develop an alternative approach: (1) we establish a proportionality relationship between k c and the peak ground acceleration (PGA), using a k -2 kinematic source model, and ( ) we analyze the PGA distribution, which is believed to be better constrained than slip images. These two methods reveal that k c follows a lognormal distribution, with similar standard deviations for both methods.

We investigate near-field ground-motion variability by computing the seismic wavefield for five kinematic unilateral-rupture models of the 1992 M w 7.3 Landers earthquake, eight simplified unilateral-rupture models based on the Landers event, and a large M w 7.8 ShakeOut scenario. We include the geometrical fault complexity and consider different 1D velocity-density profiles for the Landers simulations and a 3D heterogeneous Earth structure for the ShakeOut scenario. For the Landers earthquake, the computed waveforms are validated using strong-motion recordings. We analyze the simulated ground-motion data set in terms of distance and azimuth dependence of peak ground velocity (PGV). Our simulations reveal that intraevent ground-motion variability ϕ lnPGV is higher in close distances to the fault (< 20 km) and decreases with increasing distance following a power law. This finding is in stark contrast to constant sigma-values used in empirical ground-motion prediction equations. The physical explanation of a large near-field ϕ lnPGV is the presence of strong directivity and rupture complexity. High values of ϕ lnPGV occur in the rupture-propagation direction, but small values occur in the direction perpendicular to it. We observe that the power-law decay of ϕ lnPGV is primarily controlled by slip heterogeneity. In addition, ϕ lnPGV , as function of azimuth, is sensitive to variations in both rupture speed and slip heterogeneity. The azimuth dependence of the ground-motion mean μ lnPGV is well described by a Cauchy-Lorentz function that provides a novel empirical quantification to model the spatial dependency of ground motion. Online Material: Figures of slip distributions, residuals to ground-motion prediction equations (GMPEs), distance and azimuthal dependence, and directivity predictor of ground-motion variability for different source models.

Large scale experimentations play a relevant role in the earthquake engineering research, similarly Structural Health Monitoring is able to give information of real structures. A few geotechnical structures are documented, because only data on seismic permanent deformations are available. The present paper deals with seismic hazard of the site of the Student House at University of Molise, where a geotechnical monitoring system has been designed and is currently under implementation. It is aimed at refining the seismic hazard ...

In 2001, the Applied Technology Council (ATC) was awarded the first in a
series of contracts with the Federal Emergency Management Agency
(FEMA) to develop Next-Generation Performance-Based Seismic Design
Guidelines for New and Existing Buildings. These projects would become
known as the ATC-58 series of projects. The overall program was separated into two major phases of work: Phase 1 – Developing a Methodology for Assessing the Seismic Performance of Buildings; and Phase 2 – Developing Performance-Based Seismic Design Procedures and Guidelines.
This report is one of three principal products of the Phase 1 work, which
were first published in 2012, and have since been updated under the Phase 2 work:
• FEMA P-58-1, Seismic Performance Assessment of Buildings,
Volume 1 – Methodology, Second Edition
• FEMA P-58-2, Seismic Performance Assessment of Buildings,
Volume 2 – Implementation Guide, Second Edition
• FEMA P-58-3, Seismic Performance Assessment of Buildings,
Volume 3 – Supporting Electronic Materials and Background
Documentation, Third Edition
The three volumes together describe the seismic performance assessment
methodology for individual buildings, as well as the development of basic
building information, response quantities, fragilities, and consequence data
used as inputs to the methodology. The procedures are probabilistic,
uncertainties are explicitly considered, and performance is expressed as the probable consequences, in terms of human losses (deaths and serious
injuries), direct economic losses (building repair or replacement costs), and indirect losses (repair time, unsafe placarding, and environmental impacts) resulting from building damage due to earthquake shaking. The
methodology is general enough to be applied to any building type, regardless of age, construction or occupancy; however, basic data on structural and nonstructural damageability and consequence are necessary for its implementation.

Around the world, earthquakes continue to be a significant cause for death, injury and disruption. Recently, Malaysia startled by Sabah earthquake that struck Ranau, Sabah on 5 June 2015 with moment magnitude reported 6.0 by the United States Geological Survey while the Malaysia Meteorological department has reported the magnitude to be 5.9 at a depth approximately 10 km with it is epicenter approximately 15 km North of Ranau and which lasted for 30 seconds. There are four objectives in this review paper which are review the vary keywords used in research, studies the different types of earthquakes detector that are appropriate, review the effectiveness of earthquake detectors and the effects of installation on environment and lastly examination the output produced by the earthquake detectors through the created/ existing detectors. There are four phases involved in this part which are identification, screening, eligibility, included. Each of phases shows the flow to determine references from resources search. After identify, based on all this steps, there are only 35 articles that included in qualitative synthesis. All findings studies were discussing and analyzed based on keyword used, types of detectors, output that produce from earthquake detectors and its effects on humans, technologies and environments. From studies that has been run, there are several ideas will be recommend in this part for future studies and for the benefit of researcher. Firstly, the devices will produce the location of the nearest earthquake protection center. Next, earthquake detectors can detect heat from humans or animal within a range of distances.

The Indirect Boundary Element Method (IBEM) is used to compute the seismic response of a three-dimensional rockfill dam model. The IBEM is based on a single layer integral representation of elastic fields in terms of the full-space Green function, or fundamental solution of the equations of dynamic elasticity, and the associated force densities along the boundaries. The method has been applied to simulate the ground motion in several configurations of surface geology. Moreover, the IBEM has been used as benchmark to test other procedures. We compute the seismic response of a threedimensional rockfill dam model placed within a canyon that constitutes an irregularity on the surface of an elastic half-space. The rockfill is also assumed elastic with hysteretic damping to account for energy dissipation. Various types of incident waves are considered to analyze the physical characteristics of the response: symmetries, amplifications, impulse response and the like. Computations are performed in the frequency domain and lead to time response using Fourier analysis. In the present implementation a symmetrical model is used to test symmetries. The boundaries of each region are discretized into boundary elements whose size depends on the shortest wavelength, typically, six boundary segments per wavelength. Usually, the seismic response of rockfill dams is simulated using either finite elements (FEM) or finite differences (FDM). In most applications, commercial tools that combine features of these methods are used to assess the seismic response of the system for a given motion at the base of model. However, in order to consider realistic excitation of seismic waves with different incidence angles and azimuth we explore the IBEM.

The aim of the present paper is to present a rational procedure for the appropriate selection of the sectional forces needed for the calculation of the longitudinal reinforcement to R/C elements within the context of linear time history analysis. The proposed procedure is based on the maximum normal stresses, which occurs in each relevant cross section, and takes into consideration the critical angle of the seismic excitation, i.e., the angle that yields the maximum value of each response quantity of interest. Moreover, in an attempt to realistically interpret pertinent code provisions, three other code compatible methods of selecting the cross sectional forces are presented and compared to the here proposed method. For this purpose, three single-story buildings subjected to 47 bi-directional strong earthquake ground motions are analyzed. For each ground motion, the longitudinal reinforcement at all critical cross sections is calculated using the above four methods. Furthermore, the necessary reinforcement due to 3 and 7 representative earthquake records, required by the seismic code provisions, is determined. Comparison of results clearly shows that methods compatible with current seismic code provisions can significantly underestimate the necessary reinforcement with regards to the proposed method.

The present paper investigates the influence of the orientation of recorded horizontal ground motion components on the longitudinal reinforcement of R/C frame elements within the context of linear response history analysis. For this purpose, three single-story buildings are analyzed and designed for 13 recorded bi-directional ground motions applied along the horizontal structural axes. The analysis and design is performed for several orientations of the recording angle of the horizontal seismic components. For each orientation the longitudinal reinforcement at all critical cross sections is calculated using four methods of selecting the set of internal forces needed to compute the required reinforcement. The results show that the reinforcement calculated by three of the applied methods is significantly affected by the orientation of the recording angle of ground motion, while the fourth one leads to results which are independent of the orientation of the recording angle.

The aim of the present paper is to evaluate by means of nonlinear dynamic analysis four different procedures for the selection of sectional forces needed for the design of R/C frames. For this purpose, a single-story building is designed using four different procedures to select the sets of internal forces needed for the calculation of longitudinal reinforcement. All the four procedures are based on the results of linear response history analysis. Nonlinear dynamic analyses under 16 bi-directional ground motions are performed for 4 different seismic intensity levels. The two horizontal accelerograms of each ground motion are applied along horizontal orthogonal axes forming with the structural axes several incident angles. The results of this study demonstrate that one of the investigated procedures that takes into account the critical seismic angle is more efficient for the design of R/C frame elements.