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Abstract Geomechanical data are never sufficient in quantity or adequately precise and accurate for design purposes in mining and civil engineering. The objective of this paper is to show the variability of rock properties at the sampled point in the roadway’s roof, and then, how the statistical processing of the available geomechanical data can affect the results of numerical modelling of the roadway’s stability. Four cases were applied in the numerical analysis, using average values (the most common in geomechanical data analysis), average minus standard deviation, median, and average value minus statistical error. The study show that different approach to the same geomechanical data set can change the modelling results considerably. The case shows that average minus standard deviation is the most conservative and least risky. It gives the displacements and yielded elements zone in four times broader range comparing to the average values scenario, which is the least conservative option. The two other cases need to be studied further. The results obtained from them are placed between most favorable and most adverse values. Taking the average values corrected by statistical error for the numerical analysis seems to be the best solution. Moreover, the confidence level can be adjusted depending on the object importance and the assumed risk level.

Benford’s law predicts the frequency of the first digit of numbers met in a wide range of naturally occurring phenomena. In data sets, following Benford’s law, numbers are started with a small leading digit more often than those with a large leading digit. This law can be used as a tool for detecting fraud and abnormally in the number sets and any fabricated number sets. This can be used as an effective tool for processing data sets from laboratory tests, site investigation tests data, geotechnical design (both financial and technical) in engineering and specially included in geotechnical engineering and, etc. In this paper, data sets from geotechnical data are gathered and analyzed. It is shown that most of them follow Benford’s law. Therefore, we can use this observation for similar applications to detect the validity of data. Also, this can be assumed as an evidence for natural numbers that follow Benford’s law.

The search for petroleum is eminent in offshore environment of Southern Nigeria, while information on challenges and requirements of seabed soils at depth is limited. Available geotechnical results are inadequately quantified and documented. This study evaluates the physical state of the seabed soils for the purpose of ensuring the useful life of offshore structures. Nineteen (19) submerged soils were sampled and tested in the laboratory and in the field to obtain the required chemical and geotechnical results for analysis. Clayey silty sand and organic matter forms the succession of processes at the seabed depth. The moisture content was above 40% in most of the samples tested while the hydrogen ion concentration range is 5 ≤ pH ≤ 7. The chloride content was found to be above 100 mg/l, and sulfate concentration was below 200mg/l for all the samples. The cohesion of the soils was from 0 to 35 kN/m2 which is a characteristic of normally consolidated clays with shearing resistance angles range of 0–32°. Relatively high shear vane torque occurred at depths 26.00–26.60 m and 19.00 m–19.60 m and 21.00 m–23.00 m. The coefficient of consolidation ranged from 3.52 to 21.63 m2/yr with generally low compressibility. The moisture and chloride contents could be more attributable to soil corrosivity than other chemical variables. The results indicate that reasonable allowable loads with minimal total settlements are achievable for effective foundation; however, more geotechnical data collection is required to enable reliable and high-quality validation of the seabed foundation soil characteristics. [ABSTRACT FROM AUTHOR]

Borehole logs are important geospatial data for understanding subsurface geological and geotechnical conditions. Recently, many borehole logs in urban areas have been open to the public on the Internet in machine-readable file format. However, a few simple methods allow us to construct a voxel model of geological and geotechnical characteristics with high objectivity of the modeling process. Our work aims to develop a simple method that facilitates the use of open borehole logs in geological and geotechnical investigations in urban areas. In this paper, we propose a voxel modeling method of geotechnical data using the machine-readable open borehole logs. The method is designed to construct voxel models of lithofacies and standard penetration test results by stacking a series of horizontal two-dimensional grid data that are created by natural neighbor interpolation using geotechnical data stored in borehole logs at regular elevation intervals. A test calculation to evaluate the proposed method was performed using a large number of borehole logs in the Tokyo metropolitan area, Japan. Results confirmed that the proposed method not only allows us to ensure the objectivity of the modeling process but also provides a good overview of the three-dimensional distribution pattern of the subsurface geotechnical characteristics without any setting of complicated calculation parameters. In conclusion, the proposed method improves the efficiency of geological analyses, such as stratigraphic correlation using borehole logs, and facilitates the use of open borehole logs in urban areas. [ABSTRACT FROM AUTHOR]

Morocco's largest city, Casablanca, is expanding rapidly, but geotechnical characteristics related to the region's subsoil are rarely taken into consideration during construction/building projects. Using field studies, along with a significant database established from civil-engineering work, this study focuses on the lithological and mechanical characterization/behavior of Casablanca's subsoil in order to gain a clearer interpretation of Casablanca's (sub)soil. Lithology maps and cross-sections show the variation of Quaternary cover thickness, which is controlled by the shape of the synclines and anticlines in the folded Paleozoic bedrock. The texture of surface soils was described by percentage of gravel, sand, silt, tuff, and clay, resulting in a low to medium plastic nature, with a plasticity index (PI) between 8% and 25%. Owing to the silty nature of soils, they will likely shrink and swell against any foundation, weakening it over time. This study's analyses facilitate decision-making related to pre-construction locational choices through its identification of suitable areas for building or, if building in a less stable area, recognizing that some type of earthwork improvement should be constructed before any foundation is created. Otherwise, any construction in the Casablanca area will be at risk for foundational damages. [ABSTRACT FROM AUTHOR]

Geomechanical data are never sufficient in quantity or adequately precise and accurate for design purposes in mining and civil engineering. The objective of this paper is to show the variability of rock properties at the sampled point in the roadway's roof, and then, how the statistical processing of the available geomechanical data can affect the results of numerical modelling of the roadway's stability. Four cases were applied in the numerical analysis, using average values (the most common in geomechanical data analysis), average minus standard deviation, median, and average value minus statistical error. The study show that different approach to the same geomechanical data set can change the modelling results considerably. The case shows that average minus standard deviation is the most conservative and least risky. It gives the displacements and yielded elements zone in four times broader range comparing to the average values scenario, which is the least conservative option. The two other cases need to be studied further. The results obtained from them are placed between most favorable and most adverse values. Taking the average values corrected by statistical error for the numerical analysis seems to be the best solution. Moreover, the confidence level can be adjusted depending on the object importance and the assumed risk level. [ABSTRACT FROM AUTHOR]

The reconnaissance, mapping and analysis of kinematic features of slow-moving landslides evolving along medium-deep sliding surfaces in urban areas can be a difficult task due to the presence and interactions of/with anthropic structures/infrastructures and human activities that can conceal morphological signs of landslide activity. The paper presents an integrated approach to investigate the boundaries, type of movement, kinematics and interactions (in terms of damage severity distribution) with the built environment of a roto-translational slow-moving landslide affecting the historic centre of Lungro town (Calabria region, southern Italy). For this purpose, ancillary multi-source data (e.g. geological-geomorphological features and geotechnical properties of geomaterials), both conventional inclinometer monitoring and innovative non-invasive remote sensing (i.e. A-DInSAR) displacement data were jointly analyzed and interpreted to derive the A-DInSAR-geotechnical velocity (DGV) map of the landslide. This result was then cross-compared with detailed information available on the visible effects (i.e. crack pattern and width) on the exposed buildings along with possible conditioning factors to displacement evolution (i.e. remedial works, sub-services, etc.). The full integration of multi-source data available at the slope scale, by maximizing each contribution, provided a comprehensive outline of kinematic-geometric landslide features that were used to investigate the damage distribution and to detect, if any, anomalous locations of damage severity and relative possible causes. This knowledge can be used to manage landslide risk in the short term and, in particular, is propaedeutic to set up an advanced coupled geotechnical-structural model to simulate both the landslide displacements and the behavior of interacting buildings and, therefore, to implement appropriate risk mitigation strategies over medium/long period. [ABSTRACT FROM AUTHOR]

Seepage is a common phenomenon in earthfill dams, and one that typically warrants episodic assessment and monitoring by regulatory agencies. Geophysical surveys provide a convenient, cost-effective, and convenient means for assessing seepage, but only if they are applied in effective combinations and if the data are analyzed properly. In the present study, a self-potential survey of streaming potential and a 2D electrical resistivity tomography survey were notably successful in detecting seepage under the embankment of the nearly 90-year-old Standing Rock Dam No. 1 in South Dakota, USA. Self-potential (SP) measurements show a localized negative anomaly of up to 27 mV on the upstream side of the dam, which we interpret to be the inlet or recharge zone for seepage, and a positive anomaly of up to 20 mV on the downstream side, which we interpret to be the outlet or discharge zone. The spatial correlation between our resistivity models, SP data, and topography was excellent. Water-saturated, conductive deposits in the dam's embankment match a negative SP amplitude in the inlet or recharge area. Similarly, water-saturated electrically conductive sediments are characterized by a positive SP amplitude in the discharge area where surface seepage occurs in a topographic low. Six years of water-level measurements in the existing piezometers interpreted relative to the properties and spatial distribution of coarser-grained alluvium (sand and gravel) underneath the dam's embankment fill, suggest that most seepage occurs under the dam. Our approach to assessing seepage in this project should be widely applicable to earthfill dams worldwide, and our modeled results constitute a valuable case study. • This paper is an integrated geophysical and geotechnical investigation of water seepage through earthfill dam. • We used 2D resistivity and Self-Potential methods to discover the seepage zone. • The geotechnical data explained the main reason for seepage under the dam. • The streaming potential created by water flow is a key to detecting the seepage zone. [ABSTRACT FROM AUTHOR]

Geotechnical investigation is essentially a process of information acquisition, analysis, and application. Informatization is an attractive way to improve the efficiency of geotechnical investigation. Typical approaches divide the process of geotechnical investigation into isolated stages and only focus on the local informatization of the entire process. This leads to limitations in the improvement of geotechnical investigation efficiency, misuse of geotechnical data, and interpreted results that are incorrect. Therefore, a work flow and operational mode to address the informatization throughout the overall process of geotechnical investigation is particularly important in developing a software designed for efficient and precise geotechnical investigations. In this paper, we design a work flow and operational mode for geotechnical investigation based on a geotechnical BIM model and database. Within this work flow, the construction of a 3-D geotechnical information model and BIM-based database is taken as the main line. The constantly updated model and the database are the platform for working and analysis. As this strategy can link every stage in the whole process of geotechnical investigation, all the work can be done based on the BIM model and database in a 3-D environment, so improvement in the overall efficiency of geotechnical investigation is possible. Furthermore, the integrative center combined by the BIM model and database is targeted to reduce data errors, data conversions, and the abstractness of geotechnical data, which can improve the interpreted accuracy of these data. Finally, we use the process of geotechnical investigation at a hydropower station for experimental studies to verify the proposed work flow and operational mode. The result shows that it is feasible to design the software for an efficient and more accurate geotechnical investigation based on the proposed work flow and operational mode.

The aim of this research work is to ensure the integrity and correction of the geotechnical database which contains anomalies. These anomalies occurred mainly in the phase of inputting and/or transferring of data. The algorithm created in the framework of this paper was tested on a dataset of 70 core drillings. In fact, it is based on a multi-criteria analysis qualifying the geotechnical data integrity using the sequential approach. The implementation of this algorithm has given a relevant set of values in terms of output; which will minimalize processing time and manual verification. The application of the methodology used in this paper could be useful to define the type of foundation adapted to the nature of the subsoil, and thus, foresee the adequate budget. [ABSTRACT FROM AUTHOR]

Investigation of geotechnical vulnerability (liquefaction) and Zonation of the southern region of the Caspian Sea is my most important aim in terms of destructive earthquakes hazard potential. Past geologic events on the south coast of Caspian Sea indicates that destructive earthquakes lead to the death of numbers in this area. Remained evidence of seismic events happening indicates extensive landslides, liquefaction and soil subsidence in the residential and even natural area. Therefore, in this study determination of geotechnical vulnerability (liquefaction) intensity in southern coast of Caspian Sea against natural forces resulting from earthquakes and coastal construction via geographical information system environment (GIS) is considered as the research most important purposes. Therefore, seismic and consequence natural phenomena hazards potential are high in Southern Caspian region. The results of this study indicate that in terms of performance of instability factors such as: storm waves, sedimentary material subsidence and slide, coastal sand liquefaction, the southern part of the Caspian Sea coastal areas and sea bed sections are so vulnerable. So my aim of this study at first is to illustrate the variety of methodologies currently in use for preparation of seismic hazard maps and to evaluate basic principles of zonation for different purposes and at different scales. Guidelines and recommendations for seismic microzonation should be incorporated into seismic regulations. Indeed, by its results susceptible of risk area are determined and high risks areas are identified in terms of occurrence of geotechnical processes such as liquefaction by this recommendations many researchers apply this methods for seismic-geotechnical hazard zonation in three grade. [ABSTRACT FROM AUTHOR]

For the convenience of collaborative design, virtual construction, construction process simulation and management, Building Information Modeling (BIM) is becoming an important tool in civil engineering. The current BIM team seems to neglect the geotechnical aspect of the model, which can result in costly mistakes, especially when the project is infrastructure based. The barrier between the BIM team and the geotechnical data provider is the difficulty in extracting and assimilating data from the archived geotechnical data, which is mainly in the form of geotechnical investigation reports and geological sections. Furthermore, the geotechnical data exposed from the construction can not be linked to the original data conveniently to correct the interpretated errors in the geotechnical data, and the monitoring data cannot be combined with the original geotechnical data to find the development trend of the monitoring variables. All of this indicates that current management strategy of geotechnical data should be improved upon. Therefore, a management strategy that focuses on the full life cycle management of geotechnical data together with the BIM model to improve the accuracy of decision making in the design, construction, operation and management stages of a construction project is particularly important. In this paper, we put forward a management strategy of geotechnical data that can help to integrate geotechnical information into the BIM of a construction project in order to realize the full life cycle management of geotechnical information. In this strategy, the geotechnical data from the geotechnical investigation is archived in the form of a centralized geotechnical database and an informative geotechnical model. The centralized geotechnical database is targeted to manage the factual data, base data, result data, and metadata. The informative geotechnical model can facilitate the geotechnical being used in the three-dimensional visualization environment where the collaborative design and virtual construction are accomplished. We discuss the specific workflow of building a centralized geotechnical database and an informative geotechnical model. Finally, we use the management of the geotechnical data in a hydropower station for experimental studies to verify the proposed management strategy. The result shows that it is advantageous to manage the geotechnical data in the proposed management strategy for the BIM of a construction project. [ABSTRACT FROM AUTHOR]

The European COST Sub-Urban Action (TU1206) has had the fundamental aim of closing the knowledge gap between subsurface experts and potential users of subsurface knowledge - urban decision- makers, practitioners and researchers. The Action assembled a network involving >30 countries, 23 actively participating cities, researchers, practitioners and urban decision-makers, and brought together the fragmented research and good practice across Europe in sustainable urban sub-surface use. Development of national exemplars has been encouraged, and good practice identified to inspire others, using a lighthouse-follower approach to cascade knowledge and good practice across Europe and further afield. Experts from both sides of the knowledge gap were brought together to assess and synthesise the state-of-the-art in lighthouse cities with respect to urban sub-surface knowledge, understanding, and use of that knowledge. This was achieved in 19 City Studies, with findings encapsulated in an over-view report “Out of Sight - Out of Mind”. Expert sub-groups then identified good practice in subsurface data and knowledge locally, nationally, and Europe-wide. These are highlighted in the synthesis report “Opening up the subsurface for the cities of tomorrow”, and expanded on in seven topic review reports. These also identified key gaps in knowledge, and its use. A new concept, GEOCIM is proposed for City Quarter to Conurbation scales, combining subsurface and above-ground models. These enable: a.) holistic urban planning; b.) identifying subsurface opportunities; and c.) saving costs by reducing uncertainty in ground conditions. Finally, the Action’s reports and outputs were integrated within an online toolbox, and will be further outlined in the Final Report of the Action, to be made available on the Action’s website. The Sub-Urban Toolbox promotes and disseminates the good practice, and decision-support tools: a.) to help better inform and empower city decision- and policy-makers about the sub-surface and the vital importance of its early-stage consideration; and b.) accelerate uptake amongst sub-surface experts of sub-surface modelling workflows. Users with different backgrounds and needs, require different access to, and appropriate translations of, the Sub-Urban Toolbox. Therefore different entry points are provided for sub-surface technical experts, and urban planners, and decision- and policy-makers. As the critical mass of city decision- and policy-makers that is better aware of the sub-surface and its sustainable use expands, the potential for higher level policy consideration of the subsurface grows, and a wider range of impacts will become achievable. [ABSTRACT FROM AUTHOR]

Nine seismic refraction profiles were conducted and processed to study the near-surface sediments in the new urban area of Diriyah. The 2D geoseismic models illustrate two layers: a surface layer of soft sediments and weathered to hard limestone bedrock. Moreover, microtremor measurements were performed at 38 sites for 40 min using three-component seismographs and processed to assess the peak spectral amplitude and the corresponding fundamental resonance frequency. The seismic vulnerability index at each measurement site was estimated. These results correlate well with the geotechnical borehole data. The north-western zone is highly vulnerable due to the great thickness of the soft sediments. [ABSTRACT FROM AUTHOR]

Subsoil schematisations are a paramount activity for the execution of infrastructure earthworks. Currently, subsoil schematisations are laborious, and mostly based on correlation and interpolation of available geotechnical and geophysical in-situ data. Geotechnical in-situ testing tends to be accurate but merely provides local information, while geophysical investigations are often performed to image the subsurface, and provide valuable insight for areas. Yet, there is not always a clear way to reflect geophysical properties to soil schematisation. This paper presents a data fusion methodology to perform subsoil schematisation and parametrisation. This methodology makes use of available geotechnical, geological and geophysical data sets, and combines them by means of machine learning algorithms (Neural Networks and Random Forest). The data fusion method is applied on two case studies. The first case study concerns a large area of a flood defence line, and the second case study concerns a small polder area next to a dike. The accuracy of the data fusion algorithm is assessed by comparing its results against a validation data set, that has not been exposed to the data fusion algorithm. The performance of the two algorithms and of the parameters that govern each algorithm is discussed. The results show that both Neural Networks and Random Forest are suitable to perform subsoil schematisations. The analyses show that the Random Forest leads to a lower error on the validation data set. However, Random Forest fails to predict the occurrence of thin clay layers in the second case study, while Neural Networks are successful at it. The data fusion methodology shows the potential to enhance the subsoil schematisation procedure, by increasing the schematisation spatial resolution. [ABSTRACT FROM AUTHOR]

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In this paper, a fusion method for the settlement study of the earth dams based on geodetic and geotechnical data is developed. The developed method can be algorithmically explained as follows: (a) interpolation of the geotechnical data to the epoch of geodetic observations by four degree polynomial fitting, which serves as a low-pass filter. (b) Conversion of the initial observations into time series of the dam heights at the geodetic and geotechnical stations. (c) Fusion of the data from the two sources at different fusion levels. (d) Final decision based on the deformation parameters derived from fused data. The significant innovation of the proposed method centered upon its ability to incorporate geodetic and geotechnical observation types into a one integrated solution through fusion. The method is numerically tested for the Karkhe earth dam by using geodetic and geotechnical data from 1997 till 2009. The numerical evaluation at 229 check points indicates more than 70% improvement in the settlementmodeling based on the fusion of the geodetic and geotechnical data, as compared to the settlement modeling based on geotechnical data alone. [ABSTRACT FROM AUTHOR]

This article presents a geographical information system (GIS) which manages geotechnical data obtained from detailed geotechnical surveys as well as from in situ observations in Athens, Greece. Thoroughly examined data from more than 2,000 exploratory boreholes and trial pits located in the wider area of Athens have been incorporated using a relational database system. From the analysis of these results, thematic maps are compiled to illustrate the distribution of engineering geological information (e.g. the depth of the “Athens schist” head). In addition, a methodology for an automated GIS-aided seismic microzonation study is outlined and is being employed taking into account the aforementioned geotechnical and engineering geological information, as well as existing seismological data to estimate the variability of seismic ground motion for the southern part of Athens. [ABSTRACT FROM AUTHOR]

Storegga Silide has been studied intensively due to the development of the big Ormen Lange gas field. Both marine and glacial deposits were involved in this slide, and marine layers were the sliding planes. Data from different wireline logs in the Storegga Slide area are analyzed using principal components and cluster statistical methods to characterize the two different kinds of sediments. The results show that the marine layer with high water content, high clay content and low strength can be differentiated from the glacial deposits. Moreover, the analysis from log response are compared with the physical parameters from the geotechnical boreholes, a good correlation exists in the dataset. [ABSTRACT FROM AUTHOR]

A case history is presented of lateral spreading in two reclaimed port areas of the Cephalonia island, Greece, in the 2014 earthquake doublet (M w 6.1 & 6). Lateral ground displacements along 24 transects perpendicular to the quay walls in the two port areas were directly measured by ground surveys. Liquefaction of gravel-size fills was observed throughout the ports and was more pronounced in Lixouri port where ground motions were higher. The maximum cumulative horizontal ground displacements ranged from 3 cm to 152 cm, depending on the transect location and height of free face, whereas the inland extent of lateral ground movement ranged from 10 m to 90 m. Lateral movement of the quay walls in Argostoli Port was lower compared to Lixouri Port. Strong motion recordings in the two port areas as well as pertinent seismotectonic data are also presented along with the available geotechnical data compiled by integrating information from exploratory borings, trial pits, site geology and eye-witness accounts of the reclamation history of the areas. Average cumulative lateral displacements for groups of transects, characterized by similar height of quay wall and field conditions were derived and compared to lateral spreading predictions using an empirical relationship for free field conditions. It was found that the magnitude of lateral spreading behind the gravity-type quay walls was significantly lower compared to empirical predictions based on the assumption of free field conditions. The reduction of lateral ground movement depends on the height of quay wall and may even be an order of magnitude lower for wall heights of 6 m or greater. The findings of this study contribute in assessing quay wall movement in port areas especially when liquefaction has occurred behind the wall. • Description of seismic performance of Lixouri and Argostoli Port structures. • Measured lateral spreading of reclamation fills ranged from 3 cm to 152 cm. • The presence of multi-block quay walls reduced the lateral spreading compared to the free field. • The lateral spreading reduction was greater for the higher (and heavier) quay walls. [ABSTRACT FROM AUTHOR]

The identification of the subsoil constitutive materials, as well as the detection of possible interfaces and anomalies, are crucial for many site characterization applications. During investigation campaigns, complementary geophysical and geotechnical methods are usually used. These two sets of methods yield data with very different spatial scales and different levels of incompleteness, uncertainty and inaccuracy. In this work, a mathematical combination of geophysical and geotechnical information is proposed in order to produce a better subsoil characterization. It is shown that belief functions can be used for such a fusion process. A specific methodology is developed in order to manage conflictual information and different levels of uncertainties and inaccuracies from different investigation methods. In order to test and validate this methodology, we focus on the use of two selected methods, Electrical Resistivity Tomography (ERT) and Cone Penetration Test. First, a synthetic model with artificial data is considered, taking advantage of the results obtained to conduct a comparative study (effect of parameters and noise level). Then, an experimental test bench is considered, in which a two-layered model is placed (plaster and saturated sands) and geophysical and geotechnical data are generated, using a mini-ERT device and insertion depth values. This work also aims at providing a better graphical representation of a subsoil section with associated degrees of belief. The results highlight the ability of this fusion methodology to correctly characterize the considered materials as well as to specify the positions of the interfaces (both vertical and horizontal) and the associated levels of confidence. • Better subsoil model by belief functions for geophysical and geotechnical data fusion. • Quality of results is more sensitive to positions of boreholes than to their number. • Resulting fusion model is supplemented with associated levels of confidence. • Highlighting of areas where geophysical and geotechnical information are conflictual. • This combination methodology suggests where the survey campaign should be reinforced. [ABSTRACT FROM AUTHOR]

• This study presents the analysis of the ground deformation measured using 26 years of satellite SAR data. • We investigated the driven factors of subsidence in a densely urbanized area. • Data retrieved by several boreholes and geotechnical investigations were used to model the building load and to validate remote sensing data. • The comparison between the consolidation curve and the time series suggests that SAR data can be used to evaluate the consolidation process. This paper shows the results of the comparison between Multi-temporal Synthetic Aperture Radar (MTInSAR) products derived from different sensors (C-band ERS 1/2, Envisat, Sentinel-1 and X-band COSMO-SkyMed) and geotechnical data to investigate the driving factors of subsidence which affect a freight terminal located along the a coastal plain of Tuscany (central Italy). MTInSAR data have been acquired in a very long period, between 1992 and 2018 and were analyzed in terms of subsidence rates and deformation time series at building scale. The obtained results show that the oldest buildings are still affected by a deformation rate close to −5 mm/yr, whereas recent buildings register rates around −40 mm/yr. Time series of deformation suggest that the deformation rates decrease over time following time-dependent trend that approximates the typical consolidation curve for compressible soils. The geotechnical and stratigraphical analysis of the subsurface data (boreholes, cone penetration tests and dilatometer tests) highlights the presence of a 15 m thick layer formed of clay characterized by poor geotechnical characteristics. The comparison among InSAR data, subsurface geological framework and geotechnical reconstruction suggests a possible evaluation of the timing of the primary and secondary consolidation processes. [ABSTRACT FROM AUTHOR]