Geological-geotechnical risk mapping of gravitational mass movements in an urban area in Colombo, Brazil

This work presents a geological-geotechnical risk map of gravitational mass movements and a susceptibility map to shallow translational slides to Vila Nova community, located in the municipality of Colombo, Brazil. The first map was created through a qualitative mapping methodology and the second one was elaborated using a deterministic method of slope stability. An aerial photogrammetric survey with UAV technology was performed, as well as field reconnaissance, laboratory testing, and geoprocessing techniques. Seven slope failures were identified as well as a range of other evidences of instability associated with the predisposition of the terrain to erosive and gravitational movements linked to human intervention without urban planning and engineering techniques. Moreover, the qualitative and quantitative analyses pointed out that 13% to 9% of the study area, respectively, are in a very high-risk condition for landslides. Thus, the resulting cartographic products are presented as an important technical contribution for landslide risk management as well as land use planning for reducing the geotechnical problems faced on site.

Towards a Structured Maintenance and Integrity Management Program of Hydrocarbon Transport Systems - Emphasis on Geohazards

The main objective of the integrity and maintenance professionals of hydrocarbon transportation companies is to ensure the integrity and availability of transportation systems by monitoring and controlling the risks to which they are exposed. This article presents a series of aspects that give scope to a structured maintenance and integrity management program, and that can be established in each company based on its organizational structure and culture. Some examples are presented to take into account in geohazard management and that focus on achieving a holistic and prospective view of the professionals who manage geotechnical risk.

A Bayesian network approach for geotechnical risk assessment in underground mines

SYNOPSIS Underground mining gives rise to geotechnical hazards. A formal geotechnical risk assessment can help to forecast and mitigate these hazards. Frequentist probability methods can be used when the hazard does not have many variables and a lot of data is available. However, often there is not enough data for probability distributions, such as in the case of new projects. The risk assessment is often subjective and qualitative, based on expert judgement. The purpose of this research is to present the use of Bayesian networks (BNs) as an alternative to existing risk assessment methods in underground mines by combining expert knowledge with data as it becomes available. Roof fall frequency forecasting using parameter learning is demonstrated with 1141 sets of roof fall data across 12 coal mines in the USA. The prediction is nearly identical for individual mines, but when multiple mines are evaluated it is difficult to find a single best fit distribution for annual roof fall frequency. The BN approach with TNormal distribution was twice as likely to fit the observed data compared to the Poisson distribution assumed in the past. A hybrid approach using BN combining multiple probability distribution curves from historical data to predict annual roof fall is proposed. The BN models can account for variability for multiple parameters without increasing the complexity of the calculation. BNs can work with varying amounts of data, which makes them a good tool for real-time risk assessment in mines. Keywords: Bayesian network; expert opinion models; geotechnical risk; incident forecasting; parameter learning; roof fall risk.

Methodological recommendations for assessing geotechnical risk in dense urban development

Представлены главные положения, которые были положены в основу методических рекомендаций по оценке геотехнического риска в условиях плотной городской застройки. Приведен краткий обзор по анализу риска в геотехнике. Рассмотрены критические дефекты зданий, потенциально повышающие вероятность их обрушения. Показаны принципиальные положения экспертного и количественного анализа рисков.