Influence of irregular topography and random soil properties on coherency loss of spatial seismic ground motions

Coherency functions are used to describe the spatial variation of seismic ground motions at multiple supports of long span structures. Many coherency function models have been proposed based on theoretical derivation or measured spatial ground motion time histories at dense seismographic arrays. Most of them are suitable for modelling spatial ground motions on flat‐lying alluvial sites. It has been found that these coherency functions are not appropriate for modelling spatial variations of ground motions at sites with irregular topography (Struct. Saf. 1991; 10 (1):1–13). This paper investigates the influence of layered irregular sites and random soil properties on coherency functions of spatial ground motions on ground surface. Ground motion time histories at different locations on ground surface of the irregular site are generated based on the combined spectral representation method and one‐dimensional wave propagation theory. Random soil properties, including shear modulus, density and damping ratio of each layer, are assumed to follow normal distributions, and are modelled by the independent one‐dimensional random fields in the vertical direction. Monte‐Carlo simulations are employed to model the effect of random variations of soil properties on the simulated surface ground motion time histories. The coherency function is estimated from the simulated ground motion time histories. Numerical examples are presented to illustrate the proposed method. Numerical results show that coherency function directly relates to the spectral ratio of two local sites, and the influence of randomly varying soil properties at a canyon site on coherency functions of spatial surface ground motions cannot be neglected. Copyright © 2010 John Wiley & Sons, Ltd.     

Influence of ground motion spatial variation,site condition and SSI on the required separation distances of bridge structures to avoid seismic pounding

It is commonly understood that earthquake ground excitations at multiple supports of large dimensional structures are not the same. These ground motion spatial variations may significantly influence the structural responses. Similarly, the interaction between the foundation and the surrounding soil during earthquake shaking also affects the dynamic response of the structure. Most previous studies on ground motion spatial variation effects on structural responses neglected soil–structure interaction (SSI) effect. This paper studies the combined effects of ground motion spatial variation, local site amplification and SSI on bridge responses, and estimates the required separation distances that modular expansion joints must provide to avoid seismic pounding. It is an extension of a previous study (Earthquake Engng Struct. Dyn. 2010; 39 (3):303–323), in which combined ground motion spatial variation and local site amplification effects on bridge responses were investigated. The present paper focuses on the simultaneous effect of SSI and ground motion spatial variation on structural responses. The soil surrounding the pile foundation is modelled by frequency‐dependent springs and dashpots in the horizontal and rotational directions. The peak structural responses are estimated by using the standard random vibration method. The minimum total gap between two adjacent bridge decks or between bridge deck and adjacent abutment to prevent seismic pounding is estimated. Numerical results show that SSI significantly affects the structural responses, and cannot be neglected. Copyright © 2010 John Wiley & Sons, Ltd.     

Estimation of Nonlinear Time-dependent Soil Behavior in Strong Ground Motion Based on Vertical Array Data

To improve our understanding of nonlinear elastic properties of soils, a method is proposed of estimation of stress-strain relations of soils in situ in strong ground motion based on vertical array data. Strong motion records provided by seismic vertical arrays allow estimation of nonlinear stress-strain relations in soil layers at different depths, from the surface down to the location of the deepest device. As an example, records obtained during the main shock of the 1995 Kobe earthquake at Port-Island, SGK, and TKS sites were used to estimate the stress-strain relations in the soil profiles. For different layers, different types of nonlinear stress-strain relations were selected, according to the profiling data. To account for temporal changes in the soil behavior, consecutive parts of records were examined, and for successive time intervals, the relations were found showing the best-fit approximation to the observed data. At Port Island and SGK sites, where the strongest accelerations were recorded, the obtained stress-strain relations showed systematic changes in the upper layers (0–14 m), such as, a progressive reduction of the slopes of the stress-strain curves due to liquefaction at Port Island and reduction and recovery of the slopes at SGK and TKS sites. At the three sites, the stress-strain relations remained stable in layers below 11–14 m. Thus, the proposed approach gives us a representation of the soil behavior in layers at different depths in strong ground motion; it allows calculation of the propagation of arbitrary seismic signals in the studied profiles and estimation of nonlinear components in the ground response by the nonlinear system identification technique. The method can also be applied to evaluate the ground response at sites where profiling data are available and an imposed motion can be estimated.     

Effects of surface characteristics on infiltration patterns in an arid shrub desert

Precipitation is often the sole source of water replenishment in arid and semi‐arid areas and, thus, plays a pertinent role in sustaining desert ecosystems. Revegetation over 40 years using mainly Artemisia ordosica and Caragana korshinskii at Shapotou Desert Experimental Research Station near Lanzhou, China, has established a dwarf‐shrub and microbiotic soil crust cover on the stabilized sand dunes. The redistribution of infiltrated moisture through percolation, root extraction, and evapotranspiration pathways was investigated. Three sets of time‐domain reflectometry (TDR) probes were inserted horizontally at 5, 10, 15, 20, 30 and 40 cm depths below the ground surface in a soil pit. The three sets of TDR probes were installed in dwarf‐shrub sites of A. ordosica and C. korshinskii community with and without a microbiotic soil crust cover, and an additional set was placed in a bare sand dune area that had neither vegetation nor a microbiotic soil crust present. Volumetric soil moisture content was recorded at hourly intervals and used in the assessment of infiltration for the different surface covers. Infiltration varied greatly, from 7·5 cm to more than 45 cm, depending upon rainfall quantity and soil surface conditions. In the shrub community area without microbiotic soil crust cover, infiltration increased due to preferential flow associated with root tunnels. The microbiotic soil crust cover had a significant negative influence on the infiltration for small rainfall events (～10 mm), restricting the infiltration depth to less than 20 cm and increasing soil moisture content just beneath the soil profile of 10 cm, whereas it was not as strong or clear for larger rainfall events (～60 mm). For small rainfall events, the wetting front depth for the three kinds of surface cover was as follows: shrub community without microbiotic soil crust > bare area > shrub community with microbiotic soil crust. In contrast, for large rainfall events, infiltration was similar in shrub communities with and without microbiotic soil crust cover, but significantly higher than measured in the bare area. Soil water extraction by roots associated with evapotranspiration restricted the wetting front penetration after 1 to 3 h of rainfall. Copyright © 2006 John Wiley & Sons, Ltd.     

强震动作用下土体非线性动力特征研究发展与展望

浅地表覆盖土层动力特性对地震动影响显著,软厚土层会明显改变地震动强度及频谱特性。由于观测数据匮乏,强震动作用下土体非线性动力特征研究长期以来均以室内试验为主,但在实验室中难以可靠地模拟实际地震历程中土体承受的加载路径、边界条件、排水条件等复杂因素。近二十年来竖向台阵（至少包含一个地表测点和一个井下基岩测点）记录数据大量增加,为土体非线性动力学研究提供了新的基础数据与发展机遇,使基于现场观测的土体非线性动力特征实证研究成为可能。     

Real-time mapping of earthquake-induced landslides

Rigid sliding block analysis is a common analytical procedure used to predict the potential for earthquake-induced landslides for natural slopes. Currently, predictive models provide the expected level of displacement as a function of the characteristics of the slope (e.g., geometry, strength, yield acceleration) and the characteristics of earthquake shaking (e.g., peak ground acceleration, peak ground velocity). These predictive models are used for developing seismic landslide hazard maps which identify zones with risk of earthquake-induced landslides. Alternatively, these models can be combined with Shakemaps to generate “near-real-time” Slidemaps which could be used, among others, as a tool in disaster management. Shakemaps (a publicly available free service of the United States Geological Survey, USGS) provide near-real-time ground motion conditions during the time of an earthquake event. The ground motion parameters provided by a Shakemap are very useful for the development of Slidemaps. By providing ground motion parameters from an actual earthquake event, Shakemaps also serve as a tool to decouple the uncertainty of the ground motion in sliding displacements prediction. Campania region in Italy is studied for assessing the applicability of using Shakemaps for regional landslide-risk assessment. This region is selected based on the availability of soil shear strength parameters and the proximity to the 1980 Irpina (M _w  = 6.9) Earthquake.     

Improvement of TOPLATS‐based discharge predictions through assimilation of ERS‐based remotely sensed soil moisture values

In this paper, we investigate the possibility to improve discharge predictions from a lumped hydrological model through assimilation of remotely sensed soil moisture values. Therefore, an algorithm to estimate surface soil moisture values through active microwave remote sensing is developed, bypassing the need to collect in situ ground parameters. The algorithm to estimate soil moisture by use of radar data combines a physically based and an empirical back‐scatter model. This method estimates effective soil roughness parameters, and good estimates of surface soil moisture are provided for bare soils. These remotely sensed soil moisture values over bare soils are then assimilated into a hydrological model using the statistical correction method. The results suggest that it is possible to determine soil moisture values over bare soils from remote sensing observations without the need to collect ground truth data, and that there is potential to improve model‐based discharge predictions through assimilation of these remotely sensed soil moisture values. Copyright © 2002 John Wiley & Sons, Ltd.     

Prediction of site factors by a non‐parametric approach

The problem addressed in this paper is the estimation of the (de)amplification of ground motion at soil sites (compared to rock sites) as a function of the intensity of the ground motion. A non‐parametric empirical approach, called the Conditional Average Estimator (CAE) method, has been used, which is different from all existing approaches. Site factors (SFs) for sites characterized with V_s30 between 180 and 360 m/s were predicted for the peak ground acceleration (PGA) and the spectral accelerations by using a combined database of recorded ground motions. Based on the results of the study, site factors for PGA and selected spectral accelerations are proposed, separately for weaker and stronger ground motions. Comparisons are made with the SFs used in two standards (Eurocode 8 and ASCE 7‐10) and with SFs proposed in the literature, including four Next Generation Attenuation (NGA) ground‐motion prediction equations. The study reveals that (i) SFs depend strongly on the ground‐motion intensity. In the case of stronger ground motions, they decrease with increasing acceleration. (ii) The SFs predicted in this study agree reasonably well with the existing SFs in the case of weak ground motion. For higher intensities of ground motion, they are generally smaller than the existing ones. Copyright © 2014 John Wiley & Sons, Ltd.     

Investigation of soil water hydrological process in the permafrost active layer using stable isotopes

Here, we studied the isotope characteristics and source contributions of soil water in the permafrost active layer by collecting soil samples in July 2018 in Yangtze River basin. Soil moisture and temperature showed decreasing trends from 0–80 cm, and an increasing trend from 80–100 cm. The value of δ¹⁸O and δD first increased and then decreased in the soil profile of 0–100 cm; however, d-excess increased from 0–100 cm. δ¹⁸O values became gradually positive from the southwest to northeast of the study area, while d-excess gradually increased from southeast to northwest. The evaporation water line (EL) was δD = 7.56 δ¹⁸O + 1.50 (R² = 0.90, p < 0.01, n = 96). Due to intense solar radiation and evaporation on the Tibetan Plateau, the elevation did not impact the surface soil. The altitude effect of the soil depths of 0–20 cm was not obvious, but the other soil layers had a significant altitude effect. Soil moisture and temperature were closely related to the stable isotopic composition of soil water. The contribution of precipitation to soil water on the sunny slope was 86%, while the contribution of the shady slope was 84%. However, the contribution of ground ice to soil water on sunny slope was 14% and the shady slope was 16%. The contribution of ground ice to soil water increased with increasing altitude on the sunny slope, but the contribution of ground ice to soil water had no obvious trend on the shady slope.     

Case study of strong ground motion variations across cut slope

We evaluate the influence of topography on motions recorded at the base and crest of an approximate 3H:1V, 20 m single-faced slope. The motions were recorded during the 1983 Coalinga earthquake mainshock and two aftershocks. Mainshock peak accelerations at the crest and base transverse to the slope face were 0.59 and 0.38 g, respectively. The spectral amplification of crest motion occurred across T≈0–2 s. Differences between the crest/base motions are postulated to result principally from soil-structure interaction (base instrument is in a structure), variations in local ground response, and topography. Transfer functions quantifying soil-structure interaction (SSI) effects are evaluated and the base motion is modified at short periods to correct it to an equivalent free-field motion. The different levels of ground response at the crest and base are identified based on location-specific measurements of soil shear wave velocities. Differences between crest/base motions not accounted for by SSI or differential ground response are attributed to topographic effects. By these means, topographic spectral amplification (i.e. amplification relative to level ground conditions) is estimated to be about 1.2 at the crest and about 0.85–0.9 at the base across the period range T≈0.4–1.0 s.     

Impact of root architecture on the erosion‐reducing potential of roots during concentrated flow

Many studies focus on the effects of vegetation cover on water erosion rates, whereas little attention has been paid to the effects of the below ground biomass. Recent research indicates that roots can reduce concentrated flow erosion rates significantly. In order to predict this root effect more accurately, this experimental study aims at gaining more insight into the importance of root architecture, soil and flow characteristics to the erosion‐reducing potential of roots during concentrated flow. Treatments were (1) bare, (2) grass (representing a fine‐branched root system), (3) carrots (representing a tap root system) and (4) carrots and fine‐branched weeds (representing both tap and fine‐branched roots). The soil types tested were a sandy loam and a silt loam. For each treatment, root density, root length density and mean root diameter (D) were assessed. Relative soil detachment rates and mean bottom flow shear stress were calculated. The results indicate that tap roots reduce the erosion rates to a lesser extent compared with fine‐branched roots. Different relationships linking relative soil detachment rate with root density could be established for different root diameter classes. Carrots with very fine roots (D < 5 mm) show a similar negative exponential relationship between root density and relative soil detachment rate to grass roots. With increasing root diameter (5 < D < 15 mm) the erosion‐reducing effect of carrot type roots becomes less pronounced. Additionally, an equation estimating the erosion‐reducing potential of root systems containing both tap roots and fine‐branched roots could be established. Moreover, the erosion‐reducing potential of grass roots is less pronounced for a sandy loam soil compared with a silt loam soil and a larger erosion‐reducing potential for both grass and carrot roots was found for initially wet soils. For carrots grown on a sandy loam soil, the erosion‐reducing effect of roots decreases with increasing flow shear stress. For grasses, grown on both soil types, no significant differences could be found according to flow shear stress. The erosion‐reducing effect of roots during concentrated flow is much more pronounced than suggested in previous studies dealing with interrill and rill erosion. Root density and root diameter explain the observed erosion rates during concentrated flow well for the different soil types tested. Copyright © 2007 John Wiley & Sons, Ltd.     

Shaking table test on the seismic failure characteristics of a subway station structure on liquefiable ground

In order to investigate the seismic failure characteristics of a structure on the liquefiable ground, a series of shaking table tests were conducted based on a plaster model of a three‐story and three‐span subway station. The dynamic responses of the structure and ground soil under main shock and aftershock ground motions were studied. The sand boils and waterspouts phenomena, ground surface cracks, and earthquake‐induced ground surface settlements were observed in the testing. For the structure, the upward movement, local damage and member cracking were obtained. Under the main shock, there appeared longer liquefaction duration for the ground soil while the pore pressure dissipated slowly. The acceleration amplification effect of the liquefied soil was weakened, and the soil showed a remarkable shock absorption and concentration effect with low frequency component of ground motion. However, under the aftershock, the dissipation of pore pressure in the ground soil became obvious. The peak acceleration of the structure reduced with the buried depth. Dynamic soil pressure on the side wall was smaller in the middle and larger at both ends. The interior column of the model structure was the weakest member. The peak strain and damage degree for both sides of the interior column exhibited an ‘S’ type distribution along the height. Moreover, the seismic response of both ground soil and subway station structure exhibited a remarkable spatial effect. The seismic damage development process and failure mechanism of the structure illustrated in this study can provide references for the engineers and researcher. Copyright © 2013 John Wiley & Sons, Ltd.     

Effect of soil stiffness in the attenuation of Rayleigh-wave motions from field measurements

The amplitude of vertical ground surface vibrations generated by impact tests on the ground surface was measured at various radial distances from the point of impact at locations of Greece. The results of measurements were analyzed in the frequency domain (in the range from 0–100 Hz) and the attenuation characteristics of soil materials were studied in terms of a frequency-independent attenuation coefficient, a₀, of the empirical Bornitz equation. The aim of the study was to investigate the effect of soil stiffness (expressed by the value of low-amplitude shear wave velocity of soil, V_SO) on the value of attenuation coefficient, a₀. Values of V_SO for the tested soils were estimated by applying the methodology of Spectral Analysis of Surface Waves (SASW) technique and utilizing the surface vibration data. An empirical relationship between a₀ and V_SO1 (V_SO1 is the representative value of V_SO for the soil profile up to a depth of one wavelength) was established for values of V_SO1 ranging from 140 to 1000 m/s. A similar relationship in terms of the low-amplitude shear modulus of soil, G_O1, was also established by converting the V_SO1 values to G_O1 values. The experimental results were compared to values reported in the literature for comparable soil types and frequencies of vibration and a reasonable agreement was found to exist. The proposed empirical relationship can be utilized in many practical applications of soil dynamics requiring the knowledge of the attenuation rate of Rayleigh waves with distance in various types of soils.     

Numerical simulation of ground flow caused by seismic liquefaction

Flow failure of sandy subsoil induced by seismic liquefaction is known to cause significant damage to structures. It is induced not only by the dynamic forces exerted by seismic acceleration but also by the static gravity force in consequence of the topography of the ground. The ground flow may sometimes continue after the end of the seismic loading and finally the ground is significantly deformed to cause a failure.This paper numerically predicts the magnitude of flow that could occur when soil liquefaction continues for a sufficiently long period. It is considered that liquefied soil behaves like a viscous liquid, and hence, ground flow is governed by the principle of minimum potential energy. In the calculation, liquefied sand is assumed to be a viscous liquid that deforms in undrained conditions with its volume remaining constant. To consider the non-linearity due to large displacement, the updated Lagrangian method is used to solve the equation of motion. The Newmark β method is employed to calculate the time history of the ground motion. Finally, a simulation using this calculation method shows that the proposed method gives reasonable results for the conditions indicated.     

Bridge–embankment interaction under transverse ground excitation

Seismic performance and dynamic response of bridge–embankments during strong or moderate ground excitations are investigated through finite element (FE) modelling and detailed dynamic analysis. Previous research studies have established that bridge–embankments exhibit increasingly flexible performance under high‐shear deformation levels and that soil displacements at bridge abutment supports may be significant particularly in the transverse direction. The 2D equation of motion is solved for the embankment, in order to evaluate the dynamic characteristics and to describe explicitly the seismic performance and dynamic response under transverse excitations accounting for soil nonlinearities, soil–structure interaction and imposed boundary conditions (BCs). Using the proposed model, equivalent elastic analysis was performed so as to evaluate the dynamic response of approach embankments while accounting for soil–structure interaction. The analytical procedures were applied in the case of a well‐documented bridge with monolithic supports (Painter Street Overcrossing, PSO) which had been instrumented and embankment participation was identified from its response records after the 1971 San Fernando earthquake. The dynamic characteristics and dynamic response of the PSO embankments were evaluated for alternative BCs accounting for soil–structure interaction. Explicit expressions for the evaluation of the critical embankment length L_c are provided in order to quantify soil contribution to the overall bridge system under strong intensity ground excitations. The dynamic response of the entire bridge system (deck–abutments–embankments) was also evaluated through simplified models that considered soil–structure interaction. Results obtained from this analysis are correlated with those of detailed 3D FE models and field data with good agreement. Copyright © 2007 John Wiley & Sons, Ltd.     

Effects of inertial and kinematic interaction on seismic behavior of pile with embedded foundation

Effects of inertial and kinematic forces on pile stresses are studied based on large shaking table tests on pile-structure models with a foundation embedded in dry and liquefiable sand deposits. The test results show that, if the natural period of the superstructure, T_b, is less than that of the ground, T_g, the ground displacement tends to be in phase with the inertial force from the superstructure, increasing the shear force transmitted to the pile. In contrast, if T_b is greater than T_g, the ground displacement tends to be out of phase with the inertial force, restraining the pile stress from increasing. With the effects of earth pressures on the embedded foundation and pile incorporated in, pseudo-static analysis is conducted to estimate maximum moment distribution in pile. It is assumed that the maximum moment is equal to the sum of the two stresses caused by the inertial and kinematic effects if T_b<T_g or the square root of the sum of the squares of the two if T_b>T_g. The estimated pile stresses are in good agreement with the observed ones regardless of the occurrence of soil liquefaction.     

Quantifying the surface covering,binding and bonding effects of biological soil crusts on soil detachment by overland flow

Biological soil crusts (BSCs) have impacts on soil detachment process through surface covering, and binding and bonding (B&B) mechanisms, which might vary with successional stages of BSCs. This study was conducted to quantify the effects of surface covering, binding and bonding of BSCs on soil detachment capacity by overland flow in a 4 m long hydraulic flume with fixed bed. Two dominant BSC types, developed well in the Loess Plateau (the early successional cyanobacteria and the later successional moss), were tested using natural undisturbed soil samples collected from the abandoned farmlands. Two treatments of undisturbed crusts and one treatment of removing the above‐ground tissue of BSCs were designed for each BSC type. For comparison, bare loess soil was used as the baseline. The collected soil samples were subjected to flow scouring under six different shear stresses, ranging from 6.7 to 21.2 Pa. The results showed that soil detachment capacity (D_c) and rill erodibility (K_r) decrease with BSC succession, and the presence of BSCs obviously increased the critical shear stress, especially for the later successional moss crust. For the early successional cyanobacteria crust, D_c was reduced by 69.2% compared to the bare loess soil, where 37.7% and 31.5% are attributed to the surface covering and B&B, respectively. For the later successional moss crust, D_c decreased by 89.8% compared to the bare loess soil, where 68.9% and 20.9% contributed to the surface covering and B&B, respectively. These results are helpful in understanding the influencing mechanism of BSCs on soil erosion and in developing the process‐based erosion models for grassland and forestland. Copyright © 2017 John Wiley & Sons, Ltd.     

Analysis of the weightiness of site effects on reinforced concrete (RC) building seismic behaviour: The Adra town example (SE Spain)

The damage distribution in Adra town (south‐eastern Spain) during the 1993 and 1994 Adra earthquakes (5.0 magnitude), that reached a maximum intensity degree of VII (European Macroseismic Scale (EMS scale)), was concentrated mainly in the south‐east zone of the town and the most relevant damage occurred in reinforced concrete (RC) buildings with four or five storeys. In order to evaluate the influence of ground condition on RC building behaviour, geological, geomorphological and geophysical surveys were carried out, and a detailed map of ground surface structure was obtained. Short‐period microtremor observations were performed in 160 sites on a 100m × 100m dimension grid and Nakamura's method was applied in order to determine a distribution map of soil predominant periods. Shorter predominant periods (0.1–0.3 s) were found in mountainous and neighbouring zones and larger periods (greater than 0.5 s) in thicker Holocene alluvial fans. A relationship T = (0.049 ± 0.001)N, where T is the natural period of swaying motion and N is the number of storeys, has been empirically obtained by using microtremor measurements at the top of 38 RC buildings (ranging from 2 to 9 storeys). 1‐D simulation of strong motion on different soil conditions and for several typical RC buildings were computed, using the acceleration record in Adra town of the 1993 earthquake. It is noteworthy that all the aforementioned results show the influence of site effects in the degree and distribution of observed building damage. Copyright © 2007 John Wiley & Sons, Ltd.     

Evidence of nonlinear site response in horizontal-to-vertical spectral ratio from near-field earthquakes

The issue is addressed as to whether the horizontal-to-vertical spectral ratio (HVSR) method is sensitive to the amplitude of ground motion from near-field earthquakes. Twenty-one three-component accelerograms from two closely located similar soil sites in the town of Lefkas are used. The recordings represent 17 earthquakes covering a wide range of magnitudes, epicentral distances and azimuths. Peak horizontal accelerations (PGA) and velocities (PGV) lie in the ranges 20–540 cm/s² and 1.4–55.2 cm/s. For each HVS ratio, the site's fundamental-resonance frequency, f_res, is determined visually. Linear correlation analysis shows that f_res is strongly (negatively) correlated to PGA and PGV (r between −0.7 and −0.8); no correlation is found with resonance amplitude or epicentral distance. We show that the observed correlation is attributable to soil nonlinearity and indicate how weak-motion estimates of f_res can be corrected for use in assessing site response during strong shaking.     

Seismic microzoning from synthetic ground motion parameters: case study, Santiago de Cuba

Synthetic seismograms (P-SV and SH waves) have been calculated along six profiles in Santiago de Cuba basin, with a cutoff frequency of 5 Hz, by using a hybrid approach (modal summation for a regional 1D structure plus finite differences for a local 2D structure embedded in the first). They correspond to a scenario earthquake of M_S=7 that may occur in Oriente fault zone, directly south of the city. As initial data for a seismic microzoning, the characterisation of earthquake effects has been made considering several relative (2D/1D) quantities (PGDR, PGVR, PGAR, DGAR, I_AR—ratios of peak ground values of displacement, velocity and acceleration, and of design ground acceleration and Arias intensity-, etc.) and functions representative of the ground motion characteristics in soil (2D) with respect to bedrock (1D). The functions are the response spectra ratio RSR(f), already routinely used in this kind of work, and the elastic energy input ratio E_IR(f), defined, for the first time, in this paper. These data, sampled at 115 sites within all the profiles have been classified in two steps, using logical combinatory algorithms: connected components and compact sets. In the first step, from the original ground motion parameters or functions extracted from the synthetic seismograms, nine sets have been classified and the partial results show the spatial distribution of the soil behaviour as a function of the component of motion. In the second step, the results of the classification of the nine sets have been used as input for a further classification that shows a spatial distribution of sites with a quasi-homogeneous integral ground motion behaviour. By adding the available geological surface data, a microzoning scheme of Santiago de Cuba basin has been obtained.