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Copyright of Railway Investigation & Surveying is the property of Railway Investigation & Surveying Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents the potential of airborne LiDAR digital terrain model (DTM) for engineering geological mapping in geologically complex and forested area. The multipurpose, comprehensive engineering geological map is created for the pilot area (16.75 km2) located in the Vinodol Valley, Croatia. Eight topographic datasets were derived from 1-m DTM and visually interpreted to identify lithologies and geomorphological processes. In total, 12 engineering geological units, more than 500 landslides, and gully erosion phenomena are outlined in the pilot area. Results confirmed the greatest potential of visual interpretation of LiDAR derivatives for mapping of geomorphological processes in a large scale. On the other hand, this method allowed identification and mapping of engineering formations that are basic engineering geological units appropriate for the medium-scale engineering geological maps. The produced map represents a valuable tool for a wide range of planning and engineering purposes, as well as for geological hazard and risk assessment.

The Flims rockslide/rock avalanche (FRRA) is the largest long runout landslide in Europe. This event provides a unique opportunity to study the pre-failure and failure behavior of a large rock slope, as both the source zone and deposit of this event are accessible. In this study, we perform engineering geological and geomorphic field mapping as well as stability and runout modeling in order to explore the preconditioning and triggering factors that resulted in failure of this event, and to infer the mechanisms that governed its runout. By combining these analyses, we qualitatively comment on the mechanisms that lead to the transition from a rockslide to a long runout, catastrophic rock avalanche. Our engineering geological and geomorphic field mapping has revealed that the FRRA failed along a sliding zone that features numerous, large scale steps. Previous work at the site, as well as new analysis of thin sections, has revealed the presence of marl-like layers within the failed stratigraphic unit. Our stability analysis shows that the presence of low strength layers at the depth of the rupture surface is required for failure to initiate, and that failure could be triggered either by strong seismic shaking, elevated pore-water pressures, or a combination of both. The results of the runout analysis show that this event likely remained coherent for a large portion of its motion, and that liquefaction of alluvial sediments at the toe of the slope may have enhanced the runout distance of this rock avalanche. Combining the mapping, stability and runout modeling has shown that the basal shear strength required for the runout analysis is ∼6°–10° lower than that back-analyzed for the stability of this event. Thus, a mechanism to reduce strength along the rupture surface immediately following the initial instability was required for catastrophic failure of this event. This mechanism is poorly understood at present, but is likely crucial for understanding the transition from an initially stable slope to a catastrophic, long runout rock avalanche.

This paper presents the potential of airborne LiDAR digital terrain model (DTM) for engineering geological mapping in geologically complex and forested area. The multipurpose, comprehensive engineering geological map is created for the pilot area (16.75 km2) located in the Vinodol Valley, Croatia. Eight topographic datasets were derived from 1-m DTM and visually interpreted to identify lithologies and geomorphological processes. In total, 12 engineering geological units, more than 500 landslides, and gully erosion phenomena are outlined in the pilot area. Results confirmed the greatest potential of visual interpretation of LiDAR derivatives for mapping of geomorphological processes in a large scale. On the other hand, this method allowed identification and mapping of engineering formations that are basic engineering geological units appropriate for the medium-scale engineering geological maps. The produced map represents a valuable tool for a wide range of planning and engineering purposes, as well as for geological hazard and risk assessment. [ABSTRACT FROM AUTHOR]

Abstract Metropolitan and suburban areas in Africa are rapidly expanding with, in general, a poor safe urban management. Urban development in zones not suitable for construction leads to significant economic loss. The aggregate building damage combined with other environmental treats like drought, flooding or landsliding are enhancing African city vulnerability. Simple cartographic products made available to the general public could facilitate the first stage of planning and management considering parameters that affect building foundation. We combine here in ARCGIS geological, geomorphological and geotechnical data to provide such a framework focusing on the capital city of Antananarivo in Madagascar. The city was initially constructed on basement hills covered with a thick loose weathered layer and is expanding into the alluvial lowland watered by the Ikopa River. About 221 boreholes with pressumeters and laboratory data provide a picture of the underground characteristics, and allow the computation of the soil bearing capacity, the key parameter we used to assess building suitability. Lithology, slope, land-use and ground water level are combine to build a first geotechnical map that is completed using a mapping of the soil bearing capacity combined with land-use and geohydrological constraints. The geotechnical maps divide the city into zones with different constructive conditions that can be use as a first tool for urban development planning. Highlights • Mapping based on geomechanical properties of the underground. • GIS geotechnical mapping for a safer city extension. [ABSTRACT FROM AUTHOR]

It is proposed to construct a dam across the Geba River, Ethiopia. The paper reports the engineering geological investigations undertaken, including mapping, discontinuity surveys, core drilling, water absorption testing and sampling for laboratory tests. The complexity of the site, with limestones and interbedded limestone-shale horizons, is indicated by the variability of the RQD and Lugeon values. Of the 63 tests undertaken, some two-thirds had Lugeon values implying grouting was necessary. Following removal and replacement of the alluvial deposits in the central area, a grout curtain including two to three rows of grouting holes was recommended to a depth of 100 m for the left abutment, 35 m for the central foundation and 60 m for the right abutment. [ABSTRACT FROM AUTHOR]

This paper presents a method for transforming the information of an engineering geological map into useful information for non-specialists involved in land-use planning. The method consists of classifying the engineering geological units in terms of land use capability and identifying the legal and the geologic restrictions that apply in the study area. Both informations are then superimposed over the land use and a conflict areas map is created. The analysis of these data leads to the identification of existing and forthcoming land use conflicts and enables the proposal of planning measures on a regional and local scale. The map for the regional planning was compiled at a 1:50,000 scale and encompasses the whole municipal land area where uses are mainly rural. The map for the local planning was compiled at a 1:10,000 scale and encompasses the urban area. Most of the classification and operations on maps used spatial analyst tools available in the Geographical Information System. The regional studies showed that the greater part of Analândia's territory presents appropriate land uses. The local-scale studies indicate that the majority of the densely occupied urban areas are in suitable land. Although the situation is in general positive, municipal policies should address the identified and expected land use conflicts, so that it can be further improved. [ABSTRACT FROM AUTHOR]

The objective of this study was to propose a set of procedures to assess areas regarding the suitability of sustainable drainage systems (SuDSs) with application in a basin in the urban area of São Carlos (Brazil). The assessment was based on an analysis of 39 attributes reflecting the infiltration conditions that control the functional and constructive aspects of the systems, including subsurface drainability, stability, and groundwater contamination potential, which control the degree of suitability of each plot of land. The data obtained through engineering geological mapping procedures and physical principles were used to characterize the area, which resulted in the division of the basin into five SuDS suitability zones, ranging from favorable to restrictive. The proposed procedures proved to be efficient for analyzing the suitability of different SuDS types and the zoning of an area into terrain units. This approach can help planners identify the most appropriate SuDS types for a given unit, optimize the efficiency/cost relationship, and foresee potential environmental and construction-related challenges. In other words, this procedure enables the assessment of the suitability of SuDSs for different unit terrain types with inexpensive and environmentally efficient technological procedures and resources and can be applied at a fine geographic scale. [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]

This paper presents a methodology for the geological engineering survey of land degradation in urban environments using both remote sensing and geoprocessing tools. The area under study was the city of São Carlos, state of São Paulo, Brazil (urban and expansion area). The data presented here were obtained from earlier studies, photointerpretation and geological engineering mapping. The Envi 4.1 software package was used to prepare the digital orthophotos that served as a reference base for the information. Orthorectification of the Ikonos image (PSM, 1 m) was done and compared with other orthophotos from studies of environmental degradation in urban areas. The evolution of land degradation processes was analyzed based on the photointerpretation of aerial photographs taken on different dates and using Ikonos image. This study allowed to conclude that most of the degradation occurring in the city has been caused by unplanned land occupation, in disregard of environmental conditions, resulting in environmental degradation and thus impacting the quality of life of the urban population. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Engineering Geology & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Engineering geological mapping was carried out, at a scale of 1:100,000, in the Fortaleza Metropolitan Region, located in northeastern Brazil, to provide engineering geological information as an aid in planning land use and occupation. In this study, eight basic maps were produced drawing: urban areas, lithology, unconsolidated materials in addition to geomorphological map showing slopes, water resources, engineering geological zoning and distribution of geological–geotechnical environmental problems based on information collected through field and laboratory investigations. The region was divided into nine engineering geological zones analyzed in terms of geohazard susceptibility and foundation, excavation and waste disposal conditions. [Copyright &y& Elsevier]

Copyright of Bulletin of Engineering Geology & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper shows the results obtained from a group of simple and basic procedures used to assess slope instability in terms of shallow landslides on data-scarce hillsides at the slope unit scale. The procedures are based on engineering geological mapping to obtain geological and geotechnical data and on an adapted Hovland 3D safety factor (SF 3D) associated with a van Genuchten infiltration model to simulate the rainfall percolation. The procedures were applied on a data-scarce hillside in the Campos do Jordão municipality located in the Mantiqueira Mountains, São Paulo state, Brazil. This area was chosen because it is affected by shallow landslides due to a loss of shear strength when suction decreases or dissipates due to rainfall infiltration. The combined procedures permitted the total SF 3D to be obtained from the partial SF of each grid cell (considering 4 different rainfall events and quasi-saturation conditions) and the failure probability (SF 3D < 1) and marginal probability (1

from an engineering geological mapping study of the urban area of Ouro Preto in the state of Minas Gerais, Brazil, are presented. The goal of the study was to verify the efficacy of procedures, methods and classification schemes based on engineering geological mapping principles to generate data and maps for urban planning, restructuring (rehabilitation) and engineering projects. The study was developed at a 1:10,000 scale and based on field and laboratory studies and on the analysis and interpretation of aerial photography and satellite images. The selected study area has been urbanized for over 300 years and requires territorial planning and reorganization of land uses. The area is composed of highly variable rock types, unconsolidated materials and terrain features. Data collection and mapping were performed to identify and delineate 51 engineering geological units in terms of the spatial distribution of geological materials, genetic characteristics, mineralogy, the estimated strength, hydraulic conductivity interfaces and potential failure surfaces. All units were assessed in terms of excavatability conditions, predisposition to erosion and shallow translational landslide, suitability for sustainable urban drainage systems (SUDS), contaminant flow conditions, potential use as construction materials and foundation-related aspects. Recommendations for a detailed site investigation were made, and the suitability of geological materials for engineered fill was evaluated. A constraint zoning analysis was carried out to contextualize urban planning. The adopted procedures, methods and classification schemes were shown to be efficient when implemented in conjunction with intensive field studies and enabled the delineation of units with different engineering geological characteristics that are important for urban planning involving different users. • An engineering geological mapping, on a 1:10,000 scale, was carried out in the urban area of Ouro Preto, Brazil. • A combination of field and laboratory procedures and engineering geological classifications was used. • As part of the results engineering geological zoning and constraint maps were elaborated. • More than 50% of the study area presents 4 or more constraints. • Engineering geological data were generated and are support for urban planning and engineering works. [ABSTRACT FROM AUTHOR]