Amplitude Of Ground Motion Research Articles

Multitemporal analysis of ambient noise polarization to characterize site response in the town of Amatrice, shattered by the 2016 central Italy earthquake

SUMMARYThe Mw 6.0 earthquake that hit central Italy on 2016 August 24 caused an abnormally high level of destruction in the town of Amatrice. In order to clarify the role of site response in causing such a disaster, a series of ambient noise recordings acquired in the aftermath of the event are analysed here to identify site resonance properties from the ratios H/V between horizontal and vertical amplitudes of ground motion. Although the noise data acquisition was limited by the emergency management activities, the use of a new analysis technique, which isolates the contribution of Rayleigh waves to the noise wavefield and averages instantaneous estimates of H/V ratios, provided more stable results compared to the standard Nakamura's technique based on mean spectral ratios. The results demonstrated the occurrence of significant resonance phenomena, but without an obvious correlation with the spatial distribution of damage severity. It is apparent that the damage severity was also influenced by some additional local factors related to building vulnerability. Moreover, the time-series analysis revealed seasonal variations in the Rayleigh wave ellipticity curves likely related to the water content changes in the surface deposits and their influence on the Poisson coefficient. Finally, the new method proved capable of recognizing time-varying directions of Rayleigh wave propagation. This capability could be exploited to support other passive seismic methods (e.g. ReMi), whose results’ reliability is limited by the lack of control on wave direction origin.

Site classification and probabilistic estimation of Vs30 for the Iranian strong-motion network

Through a probabilistic approach, this study provides estimates of the time-averaged shear-wave velocity in the top 30 m of soil column (Vs30) for the stations of Iranian strong-motion network. For this purpose, we consider the strong-motion dataset of the Road, Housing and Urban Development Research Center for the period 1975–2018 from which 3828 three-component records from 1636 events with moment magnitude of >3, recorded at 892 stations (hypocentral distances of <300 km), are used in this study. The stations with known Vs30 (388 stations) are grouped into the NEHRP site classes; 3 stations in class A, 115 in class B, 213 in class C, 52 in class D, and 5 in class E. We obtain the probability density function and cumulative distribution function of the natural logarithm of horizontal-to-vertical response spectral ratio of ground-motion amplitudes, ln(H/V), at different periods as the basis for site classification and Vs30 estimation. We show that there is a strong dependency between site class and ln(H/V) at periods between 0.5 and 1.4 s. Using two classification criteria, we estimate the site class and Vs30 for 504 stations without this information. Our results show that there are 6 stations in site class A, 191 in class B, 76 in class C, 222 in class D, and 9 in class E. The residuals between observed and estimated Vs30 values (observed − estimated in logarithmic scale) do not show any trends and are consistent across all stations with a mean, standard deviation, and percentage error of 0.09, 0.19, and 15%, respectively. We also test our approach against the values obtained from the topography slope method proposed by Wald and Allen (2007), which results in a larger error with a mean, standard deviation, and percentage error of −0.41, 0.39, and 77%, respectively.

Analytical investigation of the effect of a deformable sliding layer on the dynamic response of seismically isolated structures

This paper aims to investigate the effect of the deformability of a sliding layer on the sliding displacement and acceleration response of structures subjected to harmonic and pulse ground motion excitations. A two-degree-of-freedom model is used for the simulation of the dynamic response of structures founded on sliding layers of varying deformability. The dynamic equilibrium of motion of the sliding response of the structure to the selected ground motion excitation is presented in a novel, generalized and dimensionless mathematical formulation which reduces drastically the complexity of the variables compared to the existing formulations. Based on this mathematical framework, the stick–slip behavior ranges of structures founded on a deformable sliding layer are determined and compared with the corresponding behavior ranges of structures founded on a rigid-plastic sliding layer. The combined effect of the flexibility of the isolated structure and the dimensionless ground motion amplitude on these stick–slip behavior ranges, the sliding displacement and the acceleration response of the structure is presented. The use of this deformable layer is beneficial for seismic and vibration isolation of structures as it leads to a significant reduction of their maximum acceleration response compared to the rigid-plastic sliding layer case.

Shaking Table Test Study on Flexible and Rigid Immersed Tube Tunnel in Liquefiable Soil Layer

To study the seismic response law of the immersed tunnel under different structural stiffnesses, three groups of shaking table models of immersed tunnel are carried out, including free-field model, flexible tunnel model, and rigid tunnel model. The similarities and differences of the pore water pressure and acceleration time-history between the free site and liquefiable soil layer around the flexible and rigid immersed tube tunnel are analyzed. The results show that, compared with the soil layer at the same position in the free-field, both the amplitude of acceleration and frequency component in the surrounding soil layer are affected by the stiffness of tunnel, and the influence comes greater with the larger stiffness of tunnel. When the input amplitude of seismic ground motion is small, the soil layer in the free field and the flexible tunnels share the same acceleration amplification law. The development law of pore pressure in the soil layer of test 1 was similar to test 2 but was quite different from test 3. Specifically, when the tunnel stiffness is smaller, the surrounding soil layer is easier to liquefy, with greater influence of the tunnel stiffness on the development law of pore pressure in the surrounding soil layer. The lower the soil buried depth is, the faster the pore pressure dissipates. The growth rate of tunnel strain is related to the stiffness of the structure. Generally speaking, the strain growth rate of the structure with smaller stiffness is higher under moderate earthquakes. The smaller the tunnel stiffness is, the more adaptable the tunnel is to the movement of the surrounding soil layer.

Study on the damping ratios of reinforced concrete structures from seismic response records

AbstractStructural damping ratio, which quantifies the energy dissipation of civil engineering structures under dynamic excitations, plays a critical role in structural seismic design and assessment. However, structural damping ratio is usually identified as an empirical value in design or as an optional parameter for different structure types as suggested in existing building seismic design guidelines. In the present work, the structural damping features of a variety of reinforced concrete (RC) structures under real ground motion excitations are further investigated by processing their response records reported in the Center for Engineering Strong Motion Data (CESMD) database. From the storey-by-storey methodology developed in this study, the equivalent damping ratios of the structures are estimated, and the time-varying effect of damping ratio is further explored, confirming the correlation between the damping ratio and the amplitude of ground motion. Based on a statistical analysis, an empirical relationship between the equivalent damping ratio and the peak ground acceleration (PGA) has been developed and validated, providing civil engineers with a refined basis for reasonably selecting the equivalent damping ratios during either the design or the post-earthquake assessment of RC structures.

The smooth transition GARCH model for simulation of highly nonstationary earthquake ground motions

The aim of this paper is to extend a stochastic model for simulation of highly nonstationary ground motions (GMs). In this model, the dual-tree complex discrete wavelet transform (DT-CDWT) is applied to a recorded ground motion to extract its wavelet coefficients and then the Smooth Transition Generalized Autoregressive Conditional Heteroscedastic (ST-GARCH) model is used to simulate these coefficients. This model simulates nonstationary features of real GMs greatly, because the conditional variance estimated by this model changes compatibly with the amplitude nonstationary features of real GMs. Because of having asymmetric structure, this model also estimates sudden changes in the amplitude of ground motions. Some of the special capabilities of this model are the simulation of multiple increasing–decreasing cycles in the temporal amplitude of GMs, prediction of several peaks in the frequency spectrum of GMs, estimation of steps of their energy curve, and simultaneous simulation of all shocks of a GM sequence. Also, this model simulates the time–frequency energy distribution of both wide-frequency and narrow-frequency bandwidth GMs.

Evaluation of seismic site response of submarine clay canyons using centrifuge modelling

The morphological features of submarine canyons significantly modify the amplitude, duration and frequency content of free-field seismic ground motions. This paper examines the influence of these morphological features through a series of seismic centrifuge tests on kaolin clay models with canyon sloping angles of 15, 30 and 45°. These tests were performed using the IFSTTAR (the French Institute of Science and Technology for Transport, Development and Networks) geotechnical centrifuge at an acceleration of 40g by applying a set of dynamic excitations, varying in amplitude and frequency content. The response of the clay canyon models was monitored by means of accelerometers and pore-pressure transducers. In-flight characterisation was performed on each clay model with bender element and T-bar tests prior to the application of seismic excitations. The study shows that the topographic shape of the canyon can substantially affect peak values and the frequency content of the free-field motions along the slope surface. Low-intensity seismic excitations and frequency contents along with the dominant frequency of the soil deposit were found to cause substantial amplification. In addition, the reduction of the shear modulus and the corresponding increase in damping tend to increase the fundamental site period.

Experimental study on the liquefaction characteristics of tailing sand under earthquake action and establishment of flow model

The liquefaction of tailings sand caused by seismic loads is a major problem for the safety of tailings ponds. Its liquefaction characteristics largely determine the stability of the dam. To study the flow characteristics of tailings sand after liquefaction under earthquake action, the flow characteristics of the tailings sand were liquefied by conducting a shaking table test. The flow equation is derived, and the discriminant factor of liquefaction flow is proposed. After liquefaction, the apparent viscosity in the tailings first decreases instantaneously, and then increases with the strain rate, but the apparent viscosity is almost unchanged. According to the experimental research of three types of seismic waves (Traft wave, El Centro wave, and Shanghai wave), the greater the ground motion amplitude is, the more obvious the shear thinning effect of the tailings sand and the more obvious the flow state. The proposed flow model is compared with the existing research results, which shows that the tailings sand is a fluid model after liquefaction and has good applicability. From the perspective of the relationship between the apparent viscosity and shear strain rate, the flow characteristics of saturated sand after liquefaction are studied, showing that the model is practical.

Resolvability of the Centroid‐Moment‐Tensors for Shallow Seismic Sources and Improvements From Modeling High‐Frequency Waveforms

AbstractShallow earthquakes in the depth range 0–30 km make up more than 60% of all world's earthquakes. However, resolving their seismic source parameters such as the depth and moment tensor components presents a challenge. Here, we investigate the effect of frequencies higher than 0.025 Hz on centroid‐moment‐tensor inversion for the earthquakes occurring in the top 10 km of the Earth's crust. For a synthetic source located at the depth of 1 km, the maximum amplitude of ground motion due to a vertical dip‐slip mechanism from the waveforms filtered at 0.01–0.15 Hz is about 1,400 times larger than that filtered at 0.01–0.025 Hz. We quantify the effect of this dramatic difference and other waveform differences by introducing the “balance of amplitudes” and “waveform similarity” functions for different depths and frequencies. They present a simple and fast way to estimate the resolvability of seismic sources at a given depth and frequency band. For the 20 May 2016, Mw = 5.9 Petermann Ranges earthquake in Central Australia analyzed at 0.01–0.025 Hz, a high uncertainty accompanies the estimated source parameters. When the frequency band is 0.01–0.15 Hz, the centroid depth is well constrained at 1 km and the mechanism is a thrust fault striking ~314°N and dipping ~30°NE. These simulations require accurate Earth models. Our result, obtained at higher frequencies, is in a great agreement with various other studies that have been carried out for this earthquake and confirms a 20‐km long, shallow rupture.

Ground motion prediction equation for crustal earthquakes in Taiwan

We develop a ground motion prediction equation (GMPE) for estimating horizontal ground motion amplitudes caused by crustal earthquakes, based on an integrated data set that includes strong motion recordings mainly from Taiwan earthquakes and only from large magnitude earthquakes in the NGA-West2 database. This GMPE is developed for probabilistic seismic hazard analysis study, which is introduced as a part of Taiwan Senior Seismic Hazard Analysis Committee Level 3 projects. The functional form developed by Chiou and Youngs was carefully studied to determine the key modeling parameters needed to regress against ground motion in the target region. Using this functional form, the GMPE achieves considerable improvement over previously developed Taiwan GMPEs. In particular, the use of a high-order function in magnitude scaling enables representation of the saturation effects of large earthquakes. Moreover, consideration of focal mechanisms, depth effects, and dip effects are used to correct the magnitude scaling; consideration of nonlinear site amplification is conditioned on VS30 and reference ground motion on rock; and consideration of basin depth effect is a function of Z1.0 in correlation with VS30. In addition, ground motion data used in this study are not only expanded by more than three times as many earthquakes and records compared with a previous Taiwan model but also provide the metadata of these records that were not available or were previously incomplete. In this study, we compare the proposed model with the NGA-West2 models and discuss the regional difference in ground motion in terms of spectral shape, magnitude scaling, distance scaling, depth scaling, style of faulting, and site effects. We provide median and single standard deviations of peak ground acceleration and 5% damped pseudospectral acceleration response ordinates of the orientation-independent average horizontal component of ground motion (RotD50) for the spectral period of 0.01–10 s.

2D nonlinear site response analysis of typical stiff and soft soil sites at shallow bedrock region with low to medium seismicity

In this study, an attempt has been made to estimate 2D nonlinear seismic site response of a small scale basin on typical stiff and soft soil sites in Peninsular India (PI). Six survey sites were selected from three shallow bedrock regions such as Kalpakkam, Bangalore and Vizag for which subsurface profiles are generated at these locations using Multichannel Analysis of Surface Wave -2D (MASW-2D) method. The subsurface profiles generated are classified as stiff and soft sites based on average 30 m shear wave velocity and further used for the 2D nonlinear site response analysis using the commercial program FLAC -2D. Thirteen intraplate ground motions from all around the world are selected for the site response analysis based on seismicity of the region. Results of the site response analysis were expressed in terms of short-period amplification factor (Fc) and long period amplification factor (Fs) for the intraplate shallow bedrock region. The results show that the Fc gives higher values than Fs in the case of stiff soil and it is showing a reverse trend in the case of soft soil. The trend of Fc is becoming more complex than that of the Fs especially in the case of stiff soil sites. Also, the 2D site response results were compared with conventional 1D nonlinear site response results using the program DEEPSOIL and aggravation factors were generated. Further, a parametric study has been carried out to quantitatively evaluate the effect of amplitude of ground motion on 2D site response analysis. Parametric study results show that subsurface heterogeneity is very sensitive to the low amplitude of input motion, especially in the case of stiff soil sites.

Optimal seismic isolation characteristics for bridges in moderate and high seismicity areas

This paper aims to identify the optimal properties of seismic isolation systems (SISs) for bridges in moderate seismicity areas (MSAs) and high seismicity areas (HSAs). Amplitude and spectral parameters of ground motions are proposed to identify these areas. A parametric study, with varying SIS properties, is carried out, and the seismic isolation performance is evaluated for several locations within MSAs and HSAs in North America and Europe. The optimal characteristic strength, Qd, and post-elastic stiffness, Kd, of SISs are determined for each seismic area class to minimize seismic forces and displacement demands. Results indicate that ground motions for MSAs have a rich high frequency content, causing seismic acceleration spectrum to decrease more rapidly with the elongation of the structure period. SISs with low-to-moderate energy dissipation capacities show the best performance for MSAs, while HSAs require SISs with higher damping capacities. Ranges for optimal Qd and Kd of SISs for bridges in MSAs and HSAs are proposed.

Spectral centroid ground motion amplitude anomaly before the Ms 8.0 Wenchuan earthquake

At 14:28 on May 12, 2008 (Beijing time), Wenchuan, in the Sichuan Province of China, experienced a Ms 8.0 earthquake. To investigate the spectral centroid amplitude changes that occurred before and during this earthquake, we gathered data from ten seismic stations located near the Longmenshan fault zone from May 1, 2008, to May 12, 2008. After using FFT to isolate the hourly seismic data, we then calculated the spectral centroid amplitudes in the 0.1–0.5 Hz frequency band. Overall, the spectral centroid amplitude had increased dramatically since May 10; the most anomalous amplitude increase, which likely preceded the actual seismic event itself, was recorded at YZP, the station closest to the epicenter. Once the earthquake initiated, we observed the strongest ground motion in the vertical and north-south directions along the Longmenshan fault. To further constrain any changes that occurred prior to the earthquake, we applied multi-scale wavelet decomposition to geomagnetic data collected from April 4 to May 12. The geomagnetic anomalies we found in this data correspond temporally with the spectral centroid amplitude anomalies. Based on these analyses, we inferred that the Wenchuan earthquake was driven by stress accumulation due to the compression of the Longmenshan fault system by the Bayankala Block to the west and deep obstruction by the hard basement material of the Sichuan Basin to the east. Our results agree with other investigations of the Wenchuan earthquake. We believe that the spectral centroid amplitude method is an effective and reliable technique for extracting anomaly data prior to the onset of great earthquakes, and that it can provide insight into the dynamic seismogenic process.

Extension of probabilistic seismic hazard analysis to account for the spatial variability of ground motions at a multi-unit nuclear power plant hard-rock site

Nuclear power plant (NPP) sites typically consist of multiple reactors (units). When earthquakes occur in the vicinity of these sites, effects will be experienced at all units. However, a seismic probabilistic risk assessment (PRA) of a multi-unit site typically only considers the possibility of adverse conditions at a single unit or, if multiple unit impacts are considered, typically assumes that all units at the site experience the same ground motion. This assumption of perfect correlation in ground motion is inconsistent with data from dense seismic arrays, which show that there is spatial variability in the ground motion between closely-spaced locations during the same earthquake. Moreover, such an assumption is not inherently conservative as is often assumed. To facilitate more realistic assessments, this paper proposes a method for capturing the effects of spatial variability of ground motion at an NPP site in the seismic PRA. The proposed method uses the results from an existing probabilistic seismic hazard analysis (PSHA) performed for a reference location at the site (e.g., the site seismic hazard curve and magnitude disaggregation) and then estimates the conditional probability distribution of the ground motion at a non-reference location. The proposed method accounts for the spatial variability in ground motion amplitude and includes mathematical formulations for NPP sites classified as “hard-rock.” The proposed method is developed using Bayesian networks because their graphical structure facilitates model transparency and communication. Moreover, Bayesian networks facilitate efficient probabilistic modeling and inference involving dependent random variables. However, the proposed method can be implemented more generally without using Bayesian networks as the calculation framework and commentary is provided regarding these alternative calculation options. This paper concludes with an example application using a PSHA for a hypothetical hard-rock site in the Central United States. Based on the results from the example application, we note that the perfect correlation assumption with respect to the ground motion at multiple locations/units at an NPP site may not necessarily be conservative.

The High-Frequency Decay Slope of Spectra (Kappa) for M≥3.5 Earthquakes on Rock Sites in Eastern and Western Canada

ABSTRACTSpectral decay of ground-motion amplitudes at high frequencies is primarily influenced by two parameters: site-related kappa (κ0) and regional Q (quality factor, inversely proportional to anelastic attenuation). We examine kappa and apparent Q-values (Qa) for M≥3.5 earthquakes recorded at seismograph stations on rock sites in eastern and western Canada. Our database contains 20 earthquakes recorded on nine stations in eastern Canada and 404 earthquakes recorded on eight stations in western Canada, resulting in 105 and 865 Fourier amplitude spectra, respectively. We apply two different methods: (1) a modified version of the classical S-wave acceleration method; and (2) a new stacking method that is consistent with the use of kappa in ground-motion modeling. The results are robust with respect to the method used and also with respect to the frequency band selected, which ranges from 9 to 38 Hz depending on the region, event, and method. Kappa values obtained from the classical method are consistent with those of the stacked method, but the stacked method provides a lower uncertainty. A general observation is that kappa is usually larger, and apparent Q is smaller, for the horizontal component in comparison to the vertical component. We determine an average regional κ0=7 ms (horizontal) and 0 ms (vertical) for rock sites in eastern Canada; we obtain κ0=19 ms (horizontal) and 14 ms (vertical) for rock sites in western Canada. We note that kappa measurements are quite sensitive to details of data selection criteria and methodology, and may be significantly influenced by site effects, resulting in large site-to-site variability.

ANALYSIS OF LOCAL SITE EFFECTS ON SEISMIC RESPONSE OF FRAME STRUCTURES SUPPORTED BY FOUNDATIONS AT DIFFERENT ELEVATIONS

Frame structures supported by foundations with different elevations (such as a structure on the slope) undergo different ground motions because of the local site effect. Seismic response of the structure under non-uniform excitation of ground motion is different from that under uniform excitation on upper embedding end or lower embedding end. Sites with the same height difference and different soil conditions were set up in this paper to subject them to ground motions related to different positions and the seismic response of structures built on the sites under uniform and non-uniform strong seismic excitation were compared. The results show that the predominant period and amplitude of ground motions on upper embedding end and lower embedding end are different and affected by soil conditions. The extent and law of amplification of shear force, displacement and storey drift of structures under non-uniform excitation differ from those under uniform excitation when soil changes from soft to medium-hard soil. In addition, the position and degree of plastic hinges change under non-uniform excitation compared to uniform excitation. The uniform excitation using the ground motion on the upper embedding end is not always safe for the frame structure supported by foundations at different elevations.

Ground motion simulations of Hope fault earthquakes

This paper examines ground motions for a major potential Mw7.51 rupture of the Hope Fault using a physics based simulation methodology and a 3D crustal velocity model of New Zealand. The simulation methodology was validated for use in the region through comparison with observations for a suite of historic small magnitude earthquakes located proximal to the Hope Fault. Simulations are compared with conventionally utilised empirical ground motion models, with simulated peak ground velocities being notably higher in regions with modelled sedimentary basins. A sensitivity analysis was undertaken where the source characteristics of magnitude, stress parameter, hypocentre location and kinematic slip distribution were varied and an analysis of their effect on ground motion intensities is presented. It was found that the magnitude and stress parameter strongly influenced long and short period ground motion amplitudes, respectively. Ground motion intensities for the Hope Fault scenario are compared with the 2016 Kaik¯oura Mw7.8 earthquake, it was found that the Kaikoura earthquake produced stronger motions along the eastern South Island, while the Hope Fault scenario resulted in stronger motions immediately West of the near-fault region and similar levels of ground motion in Canterbury. The simulated ground motions for this scenario complement prior empirically-based estimates and are informative for mitigation and emergency planning purposes.

A Multi Record Based Artificial Near Fault Ground Motion Generation Method

Near fault ground motion is a kind of ground motion with great damage, which is difficult to simulate. The amplitude and frequency functions of near fault ground motion vary greatly with time. When a single ground motion is used for simulation, large errors can easily occur. A method for generating near fault ground motion based on a set of actual ground motions is presented. In order to evaluate these artificially near fault ground motions, artificial ground motions and corresponding natural ground motions are input into the finite element analysis program to obtain the response of the structure. It is found that these artificial near fault ground motions are good simulations of these actual ground motions. The method of near fault ground motion can make up for the shortage of near fault ground motion.•Near Fault ground motions collected from the same earthquake with similar site characteristics are taken as sample group. Each ground motion in the sample group is considered as a record of random event.•Because this method is based on multi ground motion samples, this method can take account of the variability of each ground motion sample on the premise of considering the earthquake characteristics, then the generated ground motion are more close to the real one.•The wavelet technique and random vibration theory are applied to the analysis and simulation of ground motion. Because of the application of these two technologies, the simulation efficiency and accuracy of this method are improved.

Investigation of the relation between Vs30 and site characteristics of Iran based on horizontal-to-vertical spectral ratios

It is well known that the ground-motion amplitude of an earthquake could be extensively influenced by site effect. This study aims at providing a simple and new site amplification model for Iran based on the site fundamental frequency (fpeak) obtained from horizontal-to-vertical spectral ratio (HVSR). For this purpose, as a more reliable predictor of site amplification, HVSR have been calculated from pseudo-spectral acceleration of Iranian ground motions database consisted of 560 records from 30 events with moment magnitude ranging from 3.7 to 7.7 at epicentral distance of 1.7–297 km. Proposed HVSR model for Iran has been compared with the other regional models developed for California, Japan, Taiwan, Italy and China. In addition, the correlation of measured time-averaged shear wave velocity in the upper 30 m (VS30) in different seismograph stations with site fundamental frequency is evaluated and a new predictive relation for VS30 has been proposed for the study area.

Optimization of a Simulation Code Coupling Extended Source (k\u22122) and Empirical Green\u2019s Functions: Application to the Case of the Middle Durance Fault

We developed a ground-motion simulation code base on extended rupture modeling combined with the use of empirical Green’s functions (EGFs), adapted for low-to-moderate seismicity regions (with a limited set of EGFs), and extended its range of applicability to the lowest source-to-site distances. This code is based on a kinematic source description of an extended fault and is designed to allow complex fault geometries and to generate a ground motion variability in agreement with that of the recorded databases. The code is developed to work with a sparse set of EGFs. Each available EGF is therefore used in several positions on the rupture area. To be used in positions different of their original position, we applied to the EGFs some adjustments. In addition to the classical adjustments (i.e. time delay correction, geometrical spreading correction and anelastic attenuation correction), we propose here a radiation pattern adjustment. The effectiveness of it is tested in a numerical application. We showed noticeable improvements at the lowest distances, and some limitations when approaching the nodal planes of the subevents the recording of which were used as EGFs. We took advantage of the development of this code, its ability to work with a sparse set of EGFs, its ability to take into account complex fault geometries and its ability to master the general variability, to perform a ground-motion simulation scenario on the Middle Durance Fault (MDF). We perform simulations for a hard rock site (VS30 = 1800 m/s) and a sediment site (VS30 = 440 m/s) of the CEA Nuclear Research Site of Cadarache (France), and compared the computed ground motion with several ground motion prediction equations (GMPEs). The GMPEs slightly underestimate the sediment site but strongly overestimate the ground motion amplitude on the hard rock site, even when using a specific correction factor which adapts GMPEs predictions from rock site to hard rock site. This general ascertainment confirms the need to continue efforts towards the establishment of consistent GMPEs applicable to hard-rock conditions.