Level Of Ground Shaking Research Articles

Advanced 3D seismic hazard analysis for active compression in the Adriatic Thrust Zone, Italy

The probabilistic seismic hazard assessment contains two ingredients: (1) the seismic source model with earthquake rates and rupture parameters for specification of the statistical distribution of earthquakes in time and space and (2) the ground motion model, for estimation of ground shaking level at a site for each earthquake rupture. The selection of these models significantly impacts the resulting hazard maps, and it can be challenging, particularly in seismotectonic regions where overlapping structures, sited at different depths, coexist. Eastern Central Italy is a well-known active compressional environment of the central Mediterranean with a complex tectonic structure with a lithospheric double shear zone. In this study, we propose a seismic hazard assessment to analyze the contribution of these two shear zones as overlapping multi-depth seismogenic volumes to ground motion at a given hazard level. We specifically focus on selecting relevant and applicable parameters for earthquake rate modeling, emphasizing the importance of defining rate computation and rupture-depth parametrization in hazard analysis. To achieve this, we utilized a seismotectonic- and catalog-based 3D adaptive smoothed seismicity approach following the methodology given by (Pandolfi et al. in Seismol Res Lett 95: 1–11, 2023). Finally, we demonstrated how this innovative 3D approach can identify with high resolution the individual sources' contribution with particular attention to the depth location of structures that strongly influence the ground motion. Moreover, combining seismotectonic data with seismicity avoids the challenges associated with structures with scarce geologic, geodetic, or paleoseismological data. Our result provides detailed insights into the seismic hazard within the Adriatic Thrust Zone.

Influence of local versus national datasets on seismic loss estimates: A case study for residential buildings in the metropolitan area of Montreal, Canada

Assessing seismic losses requires information on ground shaking levels, a comprehensive inventory of elements at risk and their asset values to evaluate repair/reconstruction costs. The uncertainties associated with these parameters are often significant and the available data are often incomplete. This study aims to assess the value and utility of detailed data in refining seismic risk estimates. Over several years, detailed site conditions and residential exposure datasets were compiled for Greater Montreal. These models were used to estimate building damage and associated losses for various seismic scenarios. Recently, Natural Resources Canada developed a national exposure model to provide a National Earthquake Risk Profile using data derived from existing sources such as topographic maps and census data. This paper compares seismic loss projections for residential buildings using the local dataset as a baseline with those from the national model using OpenQuake and the latest Seismic Hazard Model. The local site model is based on in situ data and site measurements, while the global, proxy-based model relies on USGS correlations between slope topography and site classification. Results show that the global model overestimates seismic hazards, resulting in 30% higher residential losses than the local model. Absolute losses are increased by a factor of 3.6–5.6 depending on the building classification when using the national exposure model compared to the local inventory while relative losses are increased by a factor of 1.1–1.5. These results emphasize the need to develop detailed seismic risk assessment databases for accurate risk assessments, and for selecting appropriate risk reduction measures.

Epistemic Uncertainty in Ground-Motion Characterization in the Indian Context: Evaluation of Ground-Motion Models (GMMs) for the Himalayan Region

Abstract One of the major challenges in probabilistic seismic hazard analysis (PSHA) studies, particularly for risk-based decision-making, is to constrain epistemic uncertainties. Epistemic uncertainty associated with ground-motion characterization (GMC) models exerts a strong influence on the hazard estimate for a given target level of ground shaking. In the Indian context (mainly along the Himalayan arc), constraining epistemic uncertainty is a significant challenge owing to the lack of recorded data. This study investigates the epistemic uncertainty associated with ground-motion models (GMMs) considered appropriate for the Himalayan region. First, a review of GMMs considered applicable to the Himalayan region is provided. Subsequently, a graphical comparison of median models is performed, followed by residual and statistical analysis. The evaluation utilizes observations from a recently compiled strong-motion dataset across the Himalayas and Indo-Gangetic plains of northern India. The dataset comprises 519 acceleration traces from 150 events in the moment magnitude (Mw) range Mw 3–7.4, recorded at epicentral distances in the range REpi<300 km. The analysis demonstrates significant between-model variability, particularly with regard to median magnitude and distance scaling. The residual analysis also indicates a large bias and aleatory uncertainty. Moreover, some of the GMMs exhibit trends with distance and magnitude. Overall, our evaluation analysis shows that there is clearly significant aleatory and epistemic uncertainty associated with the GMC modeling owing to the paucity of recorded data. The range of epistemic uncertainty represented by the GMMs (available in the literature) is much larger than that typically captured by the (multiple) global models often used in PSHA studies across India.

Assessing the alerting capabilities of the Earthquake Network early warning system in Haiti with Monte Carlo simulations

Smartphone-based earthquake early warning systems implemented by citizen science initiatives are characterised by significant variability in their smartphone network geometry. This has a direct impact on the earthquake detection capability and system performance. Here, a Monte Carlo-based simulation framework is implemented to infer relevant earthquake detection quantities such as detection distance from the epicentre, detection delay, and warning time for people exposed to high ground shaking levels. The framework is applied to Haiti, which has experienced deadly earthquakes in recent decades, and to the Earthquake Network citizen science initiative, which is popular in the country. It is found that warning times of up to 12 s for people exposed to intensities between 7.5 and 8.5 on the modified Mercalli scale are possible starting from a relatively low involvement of citizens in the initiative (i.e., from 1 Haitian in 10,000).

Seismic fragility matrices for large scale probabilistic structural safety assessment

Structural safety assessment of urbanised areas exposed to seismic risk is a complex task and can be approached at different scales. Fragility functions are the most effective tool to perform an estimation of the structural risk, since they describe the exceeding probability of the limit state of interest given a level of ground shaking. The formulation of a fragility function is based on the selection of an Intensity Measure of the ground shaking, commonly represented by peak-ground or spectral parameters or by macroseismic intensity grades. In the present paper, a novel approach to estimate the seismic vulnerability at a large scale of urbanised areas is presented. The scenario earthquakes are selected according to the current formulation of the seismic hazard disaggregation provided by National and International codes, i.e. through the disaggregation in terms of magnitude (M), epicentral distance (R) and number of standard deviation from the median ground motion (ε). To this aim, a vectorial seismic Intensity Measure is assumed to compute structural safety at large scale, and a change of variables is made to turn the traditional fragility curve into a matrix. Typological fragility matrices are processed and combined to define the so-called Urban Fragility Matrices, representative of the vulnerability of selected urban sectors. The procedure is then implemented and validated referring to the city of Pozzuoli (Southern Italy) and its effectiveness validated with reference to the damage survey relative to the 4th October 1983 seismic event which struck the city, resulting a good matching between predicted and observed scenarios.

Assessing the potential implementation of earthquake early warning for schools in the Patras region, Greece

Earthquake early warning (EEW) is currently deemed a credible approach to seismic resilience enhancement in modern societies, especially if part of a more holistic earthquake mitigation strategy involving other risk reduction tools such as structural upgrading/retrofit. Yet, there remains a strong need to 1) assess the feasibility of EEW in various seismotectonic contexts, considering specific target applications/end users; and 2) develop next-generation decision-support systems relying on interpretable probabilistic impact-based estimates toward more risk-informed decision-making on EEW installation/alert triggering. These challenges are addressed in this paper, which showcases a series of recent significant EEW contributions by the authors. First, we present the results of a state-of-the-art feasibility study for EEW in schools performed across the Patras region of Greece, attempting to spatially combine traditional seismologically-driven EEW decision criteria (i.e., warning time) with proxy risk-oriented measures for earthquake impact (i.e., building fragility and the number of exposed school students). These results show that, under certain conditions, EEW could be effective for the schools in the considered case-study region. We then demonstrate an advanced end-user-centred approach for improved risk-informed decision-making on triggering EEW alerts. The proposed methodology integrates earthquake-engineering-related seismic performance assessment procedures and metrics with multi-criteria decision-making (MCDM) within an end-to-end probabilistic framework. The performance-based earthquake engineering component of such a framework facilitates the computation of various damage/loss estimates (e.g., repair cost, downtime, and casualties) by combining target-structure-specific models of seismic response, fragility, and vulnerability with real-time ground-shaking estimates. Additionally, the incorporated MCDM methodology enables explicit consideration of end-user preferences (importance) towards the estimated consequences in the context of alert issuance. The developed approach is demonstrated using an archetype school building for the case-study region, for which we specifically investigate the optimal decision (i.e., “trigger” or “don't trigger” an EEW alert) across a range of ground-motion intensity measures. We find that the best action for a given level of ground shaking can vary as a function of stakeholder preferences.

To Evaluate the Seismic Response of a Building Having Stiffness Irregularity and Plan Irregularity with Quintuple Friction Pendulum System

Abstract: Quintuple friction pendulum (QFPS) bearing is a new generation sliding isolation system having multiple spherical sliding surfaces. The friction isolation system with single sliding surface is designed for a specific level of ground shaking, which may prove ineffective in case of other hazard levels. The QFPS bearing on the other hand, exhibits adaptive behavior and imparts greater amount of flexibility to the designer for various levels of earthquake shaking. Here, the effectiveness of Quintuple Friction pendulum system is carried out to study the seismic demands of base-isolated building frames with stiffness irregularities and plan irregularities subjected to various earthquake ground motions i.e. Far field ground motion, near field ground motion with fling step and near field ground motion with forward directivity by comparing their estimates with the benchmark responses obtained by the Non-Linear Time History Analysis (NLTHA). SAP 2000 Software has been used for the same. The two soft storey buildings and two buildings with plan irregularity will be modelled and analyzed. The seismic demands namely, Inter story drift, peak storey acceleration, maximum base shear are considered for the study.The reduction in absolute acceleration is found more in case of PI as compared to SS for all the considered time histories. The reduction in Maximum Base-Shear is found more in case of Plan irregularity as compared to Stiffness Irregularity (Soft Story) in all the considered Time History. In isolated structure, the Inter-storey drift is found to be maximum in case of structure having soft storey as compared to plan irregularity 1 and 2. Keywords: Multi storied RC structures, Plan irregularities, Soft storey, Quintuple Friction Pendulum, Non linear Time History Method(NLTHM)

Seismic Velocity Recovery in the Subsurface: Transient Damage and Groundwater Drainage Following the 2015 Gorkha Earthquake, Nepal

AbstractShallow earthquakes frequently disturb the hydrological and mechanical state of the subsurface, with consequences for hazard and water management. Transient post‐seismic hydrological behavior has been widely reported, suggesting that the recovery of material properties (relaxation) following ground shaking may impact groundwater fluctuations. However, the monitoring of seismic velocity variations associated with earthquake damage and hydrological variations are often done assuming that both effects are independent. In a field site prone to highly variable hydrological conditions, we disentangle the different forcing of the relative seismic velocity variations δv retrieved from a small dense seismic array in Nepal in the aftermath of the 2015 Mw 7.8 Gorkha earthquake. We successfully model transient damage effects by introducing a universal relaxation function that contains a unique maximum relaxation timescale for the main shock and the aftershocks, independent of the ground shaking levels. Next, we remove the modeled velocity from the raw data and test whether the corresponding residuals agree with a background hydrological behavior we inferred from a previously calibrated groundwater model. The fitting of the δv data with this model is improved when we introduce transient hydrological properties in the phase immediately following the main shock. This transient behavior, interpreted as an enhanced permeability in the shallow subsurface, lasts for ∼6 months and is shorter than the damage relaxation (∼1 yr). Thus, we demonstrate the capability of seismic interferometry to deconvolve transient hydrological properties after earthquakes from non‐linear mechanical recovery.

Loreto Intermediate Depth Earthquake of 26 May 2019 (Northeast Peru): Source Parameters by Inversion of Local to Regional Waveforms and Strong-Motion Observations

AbstractThe Loreto earthquake of 26 May 2019 occurred below the extreme northeast part of Peru at a depth of 140 km within the subducting Nazca plate at a distance of 700 km from the trench Peru–Chile. The orientation of the seismic source was obtained from waveform inversion in the near field using velocity and strong-motion data. The rupture occurred in normal faulting corresponding to a tensional process with T axis oriented in east–west direction similar to the direction of convergence between the Nazca and South America plates. The analysis of the strong-motion data shows that the levels of ground shaking are very heterogeneous with values greater than 50 Gal up to distances of 300 km; the maximum recorded acceleration of 122 Gal at a distance of 100 km from the epicenter. The Loreto earthquake is classified as a large extensional event in the descending Nazca slab in the transition from flat-slab geometry to greater dip.

Seismic isolation design of structure using variable friction pendulum bearings

Herein, analytical and experimental investigations are conducted to characterize the performance of a novel variable friction pendulum bearing (VFPB) capable of progressively exhibiting different hysteretic properties for different displacement amplitudes. An analytic scheme comprising existing nonlinear elements is proposed, which can be easily implemented using currently available analysis software. The analytic-scheme accuracy is verified through comparison with experimental data. Thereafter, a design method is developed for seismically isolated buildings employing VFPB. Elastic-plastic time-history analyses are performed to study the seismic performance of the base-isolated building using VFPB, by comparing its performance with that of a friction pendulum bearing (FPB). Both the buildings isolated employing VFPB and FPB exhibit excellent aseismic performance. The VFPB is more effective than FPB in reducing the response of superstructure without increasing isolator displacement for the rare earthquake scenario, especially for very rare earthquake scenario. The stiffness and damping of VFPB change to predictable values at calculable and controllable displacement. Therefore, it can be designed to achieve multiple performance objectives corresponding to different levels of ground shaking.

A new approach for a fully automated earthquake monitoring: the local seismic network of the Trentino region (NE Italy)

An application of the Complete Automatic Seismic Processor (CASP) for seismic monitoring is presented. Its integrated and iterative fully automatic procedure is able to achieve complete data analysis and significantly rapid elaborations. Its performance in real-time seismic monitoring and alerting is tested in the Trentino region (NE Italy) for the period 1st March 2018 – 31st August 2019. CASP precisely and accurately located 386 seismic events, with local magnitudes in the -0.8–3.4 range, and produced a seismic catalogue with a magnitude of completeness around 1.1. Automatic earthquake solutions, with average horizontal and vertical errors of 1.1 and 1.5 km, are very similar to those included in a manually revised reference catalogue. In addition, 146 detected events are located in the area of the local porphyry quarries. CASP alerts are delivered as Short Message Service (SMS), Telegram and e-mail messages within an average time of just over two minutes from the earthquake origin time. These alerts contain earthquake source parameters, ground shaking levels and instrumental intensities. CASP reliability, promptness and robustness permit to civil protection and decision makers to perform a monitoring primarily dedicated to emergency management, in order to evaluate both seismic sources and their effects (peak ground acceleration) at local targets, such as more inhabited territories and critical infrastructures (dams and hydropower plants).

The 2018 update of the US National Seismic Hazard Model: Where, why, and how much probabilistic ground motion maps changed

The 2018 US Geological Survey National Seismic Hazard Model (NSHM) incorporates new data and updated science to improve the underlying earthquake and ground motion forecasts for the conterminous United States. The NSHM considers many new data and component input models: (1) new earthquakes between 2013 and 2017 and updated earthquake magnitudes for some earlier earthquakes; (2) two updated smoothed seismicity models to forecast earthquake rates; (3) two suites of new central and eastern US (CEUS) ground motion models (GMMs) to translate ground shaking for various earthquake sizes and source-to-site distances considered in the model; (4) two CEUS GMMs for aleatory variability; (5) two CEUS site-effect models that modify ground shaking based on alternative shallow site conditions; (6) more advanced western US (WUS) lithologic and structural information to assess basin site effects for selected urban regions; and (7) a more comprehensive range of outputs (22 periods and 8 site classes) than in previous versions of the NSHMs. Each of these new datasets and models produces changes in the probabilistic ground shaking levels that are spatially and statistically analyzed. Recent earthquakes or changes to some older earthquake magnitudes and locations mostly result in probabilistic ground shaking levels that are similar to previous models, but local changes can reach up to +80% and −60% compared to the 2014 model. Newly developed CEUS models for GMMs, aleatory variability, and site effects cause overall changes up to ±64%. The addition of the WUS basin amplifications causes changes of up to +60% at longer periods for sites overlying deep soft soils. Across the conterminous United States, the hazard changes in the model are mainly caused by new GMMs in the CEUS, by sedimentary basin effects for long periods (≥1 s) in the WUS, and by seismicity changes for short (0.2 s) and long (1 s) periods for both areas.

Design Response Spectra and Site Coefficients for Various Seismic Site Classes of Guwahati, India, Based on Extensive Ground Response Analyses

Seismicity of northeast India and its surroundings is governed by complex tectonic setting. Guwahati, the largest city of northeast India, had suffered minor to major damages during past earthquakes (EQs). Known seismic source information also suggests that Guwahati is susceptible for future EQs both from nearby as well as distance source. Taking into account the subsoil information of Guwahati, present work attempts to understand the role of Guwahati soil during probable seismic excitation. In the absence of regional ground motion records, covering a possible variation in ground motion characteristics, which can occur during potential future EQ, 30 globally recorded ground motions are used as input motions in this work. Each input motion is applied to each of the 225 boreholes resulting in 225 × 30 = 6750 ground response analyses using equivalent linear approach. Based on the response of subsoil to each input motion, site coefficients as well as average response spectra for various seismic site classes are proposed. It has to be mentioned here that in comparison to previous works which attempted to understand the subsoil of Guwahati based on specific location-based subsoil information and specific scenario EQ, present work provides a broader picture of soil response which can be applied to any level of ground shaking. Further, based on predominant period, suggestion of maximum building storeys are suggested for Guwahati. In addition, based on the work, characteristics of EQ scenario, which can trigger maximum response from local soil of Guwahati, are assessed. Based on the present analyses, design response spectra of Guwahati are also proposed. Keeping in mind Government of India’s policy towards the development of northeast India and further to develop Guwahati as “Smart city”, the present findings will be very useful in city planning, estimation of induced effects as well as for seismic design of probable infrastructure in Guwahati.

Hazard-Consistent Earthquake Scenario Selection for Seismic Slope Stability Assessment

Design ground shaking intensity, based on probabilistic seismic hazard analysis (PSHA) maps, is most commonly used as a triggering condition to analyze slope stability under seismic loading. Uncertainties that are associated with expected ground motion levels are often ignored. This study considers an improved, fully probabilistic approach for earthquake scenario selection. The given method suggests the determination of the occurrence probability of various ground motion levels and the probability of landsliding for these ground motion parameters, giving the total probability of slope failure under seismic loading in a certain time interval. The occurrence hazard deaggregation technique is proposed for the selection of the ground shaking level, as well as the magnitude and source-to-site distance of a design earthquake, as these factors most probably trigger slope failure within the time interval of interest. An example application of the approach is provided for a slope near the highway in the south of Sakhalin Island (Russia). The total probability of earthquake-induced slope failure in the next 50 years was computed to be in the order of 16%. The scenario peak ground acceleration value estimated from the disaggregated earthquake-induced landslide hazard is 0.15g, while the 475-year seismic hazard curve predicts 0.3g. The case study highlights the significant difference between ground shaking scenario levels in terms of the 475-year seismic hazard map and the considered fully probabilistic approach.

Comparative Seismic Fragility Analysis of Conventional and Base Isolated Hospital Buildings Having Different Structural Systems

ABSTRACT After the 2010 Maule earthquake, Chilean authorities now require the implementation of base isolation systems in new public hospital build-ings. However, in Chile the typical seismic force-resisting system of non-isolated hospitals is made up of reinforced concrete shear walls, whereas that of isolated buildings is made up of reinforced concrete frames. Since the former is much stiffer than the latter, there is then a question on the actual effectiveness of base isolation in reducing the seismic demands on new hospitals with respect to that on conventional hospitals, particularly the interstory drift demand under relatively low levels of ground shaking. Motivated by this context, this study evaluates the main results of a comparative analysis of the seismic performance of isolated and non-isolated hospitals considering the typical structural system in each case. Representative structural layouts were defined for both types of hospital buildings based on the Chilean state of the practice. Further, possible influence of the number of stories was considered. Member sizes and isolation system properties were determined in accordance to the current Chilean seismic design codes. The structural models were subjected to nonlinear time history analyses under two simultaneous horizontal components of ground motions selected from the Chilean database of earthquake records. The seismic response was evaluated through fragility curves, which were developed from results given by incremental dynamic analysis. Several limit states associated with the isolation systems, structural elements and nonstructural components of hospitals were considered. Results are compared with empirical observations on the effects of earthquakes on the Chilean building inventory, and the suitability of limit state thresholds defined in the literature is discussed.

Simplified calculation of roof accelerations in existing low-rise symmetric unreinforced masonry buildings with flexible diaphragms

A formulation is presented for simplified evaluation of the roof acceleration response for the purpose of assessing non-structural components in unreinforced masonry buildings with flexible diaphragms excluding torsional effects. The method is based on modal calculations that are further studied through nonlinear time-history analysis (NLTHA) of four case study buildings. The NLTHA results for a relatively small level of ground shaking was used to validate the overall ability of the simplified modal method to predict the diaphragm flexibility effects. The NLTHA results were also used to discuss the effects of the building inelastic response in the conservatism of the simplified modal technique. It was found that, in lieu of a comprehensive modal analysis, it is possible to calculate roof accelerations in symmetric low-rise buildings with flexible diaphragms using a simplified two-mode modal method. Based on this study, a predictive method is proposed for conservative estimation of peak roof accelerations in these buildings.

Prediction of peak ground acceleration for Himalayan region using artificial neural network and genetic algorithm

Level of ground shaking in terms of peak ground acceleration (PGA) is used to carry out seismic hazard analysis of a region and has a great importance for designing earthquake resistant structures. Thus, prediction of PGA for an earthquake is very important. This paper presents a study to predict PGA of strong ground motion using the earthquake data recorded in rock sites of Himalayan region, India by using artificial neural network (ANN) and genetic algorithm (GA). In the present study, magnitude and hypocentral distance of an earthquake event has been used as input parameters and PGA recorded at different hypocentral distances have been used as output parameter for construction of ANN and GA model. Ninety percent data have been used for training and 10% testing purposes for both the ANN and GA model. Chi-square test results also reveals the successful application of ANN and GA for predicting PGA data site even with the lesser available data of a study region. The comparison of predicted PGA values from current study holds quite well with the other available developed attenuation relationships for the study region. The present study depicts the successful application of ANN and GA for predicting PGA data site even with the lesser available data of a study region.

Damage index fragility assessment of low-rise light-frame wood buildings under long duration subduction earthquakes

This paper presents fragility curves for conventional low-rise light-frame wood buildings in southwestern British Columbia, Canada, for long duration subduction earthquakes. Computational models of four representative two-story houses (two engineered and two non-engineered) are developed and validated using full-scale shake table testing data. Damage states are evaluated using the Park and Ang damage index. Incremental dynamic analyses are employed for calibrating and assessing the index. Duration effects are investigated by using 30 long duration subduction motions and 30 “spectrally equivalent” short duration crustal motions. The results indicate that the considered houses are more vulnerable to damage under subduction motions which increase the median damage indices of both individual shearwalls and entire lateral systems for all four houses at the same level of ground shaking. The correlation between system damage indices with ground motion duration was dependent on the level of ground shaking and the seismic resistance of the systems. The results further demonstrate that exterior stucco finish greatly reduces the seismic damage and can be used as an effective seismic retrofit strategy for conventional non-engineered wood construction.

A földrengéskockázat elemzése valószínűségi módszerrel

The goal of seismic hazard engineering analyses is to ensure that the planned structures can withstand a given level of ground shaking. There is a great deal of uncertainty about the location, size and resulting ground motion intensity of future earthquakes. Probabilistic Seismic Hazard Analysis (PSHA) tries to quantify these uncertainties, and combine them to produce an explicit description of the future shaking that may occur at a site.This work demonstrates the application of the method by specific calculative example. The probability (that is more than the average) of ground motion intensity is calculated by PSHA equations in the most dangerous zone of Hungary regarding earthquakes.We can read only a little about the mathematical background of the PSHA method in Hungarian journals or books. The aim of this work is to help the reader understand the application and the limitations of PSHA with the help of the probability theory.

Approximation of Shear Wave Velocity Using MASW Method for Seismic Hazard Mitigation: A Preliminary Study of Banda Aceh City Indonesia

Earthquake 9.1 SR happened in the Aceh Province Indonesia that followed tsunami on December 2004. After this event, the development of infrastructures in Banda Aceh city has shown rapidly progress. Therefore, learning of the experience of this natural event that has caused many casualties and infrastructures, the Banda Aceh city has been being taken initiative as a city that is friendly of disasters. The research objective analysed of influence sedimentation behaviour at buildings. The shear wave velocity parameters using MASW method were used for sediment characteristic assessment. The sediment characteristics are very soft, soft, dense and very dense that it’s have level different of shaking, respectively. The detail of 1D profiles of shear wave velocity have obtained. In this case, we analysed VS30 parameters of eleven locations of all measurements at the Ulee Kareng Sub District, Banda Aceh city. The ground shaking level of sediment layer depend of sedimentation characteristics. The sediment characteristic of Ulee Kareng Sub District, Banda Aceh has shown medium dense and soft soil.