Andreas Benardos

Estimating landslide susceptibility through a artificial neural network classifier

A landslide susceptibility analysis is performed through an artificial neural network (ANN) algorithm, in order to model the nonlinear relationship between landslide manifestation and geological and geomorphological parameters. The proposed methodology can be divided into two distinctive phases. In the first phase, the methodology introduces a specific distance metric, the Mahalanobis distance metric, to improve the selection of non-landslide records that “enriches” the training database and provides the model with the necessary data during the training phase. In the second phase, the methodology develops a ANN model that was capable of minimizing the effect of over-fitting by monitoring in parallel the testing data during the training phase and terminating the process of learning when a certain acceptable criteria are achieved. The model was capable in identifying unstable areas, expressed by a landslide susceptibility index. The proposed methodology has been applied in the County of Xanthi, in the northern part of Greece, an area where a well-established landslide database existed. The landslide-related parameters that had been taken in account in the analysis were the following: lithology, distance from geological boundaries, distance from tectonic features, elevation, slope inclination, slope orientation, distance from hydrographic network and distance from road network. These parameters have been normalized and reclassified and used as input variables, while the description of a given area as landslide/non-landslide was assumed to be the output variable. The final outcome of the model was a geospatial product, which expressed the landslide susceptibility index and when compared with an up-to-date landslide inventory database showed satisfactory results.

Underground aggregate mining in Athens: a promising investment plan

The introduction of stricter environmental regulations regarding the operation of open-pit quarries in the wider area of Athens has resulted in the closure of many quarrying operations. The aggregate production cannot further ensure the meeting of demand in the area and alternative schemes are being examined so as to provide long-term solutions to that issue. This paper focuses on the development of underground aggregate exploitations in the region, providing the basis for an in depth financial appraisal supported by the mine design process which also involves the utilisation of the underground space. It is proved that beyond the environmental advantages offered by this particular solution, underground limestone mining is also an attractive investment plan. Critical importance to the latter plays the space utilisation process that can be looked as a real estate development project.

Underground space development: setting modern strategies

Underground space development is an irreversible trend especially in urban environments. At this time the underground facilities have proved their usefulness in terms of efficiency and environmental friendliness. Nevertheless, in order to fully exploit the subsurface, new strategies need to be adopted in the whole context of city planning. This includes the introduction of new terms such as the valuation of the underground space, the adoption of integrated planning and zoning policies of the underground uses and the modernisation of the legal framework to incorporate the three-dimensional partition of the property. This paper discusses these issues, the adoption of which can lead to the development of a strategic underground plan, facilitating and further mobilising the hidden potential of underground space utilisation.

Room and Pillar Design and Construction for Underground Coal Mining in Greece

The underground mining is the only potential way for the utilization of the lignite reserves from an open pit exploitation which could remain unexploited due to high stripping ratios. This paper is dealing with the findings of a pilot scale underground exploitation that was developed in the Prosilio open pit coal mine in Northern Greece. The method used is the room and pillar mining method where the initial entry galleries are driven into the coal seam starting from the surface excavation face, as used in the highwall mining cases. The design of the mining scheme is presented in detail along with the building of the 3D numerical model which simulates the overall development of the pilot mine. The evaluation of the stability conditions is further discussed and analysed with the use of the results of the numerical model and through their validation with the findings and observations of the actual excavation’s response. The mine scheme selected exhibited its flexibility in coping with the prevailing conditions and its performance, in terms of the stability conditions attained, further supporting the development of a large scale underground coal excavation.