Boreholes plans optimization methodology combining geostatistical simulation and simulated annealing

Nowadays, the prospection plans have the difficult task of ensuring a more complete and rich characterization of the rock mass for the purpose of optimizing costs and increasing safety in geotechnical projects. Currently, boreholes location and depth are mainly defined based on experience and know-how of professionals, as such, it is user-dependent. Hence, there is a lack of methodologies to help the decision-makers in defining the optimal location of boreholes (with relevant information). Therefore, this paper presents a methodology based on the use of geostatistical conditional simulation allied to a stochastic global optimization algorithm (Simulated Annealing) to develop optimized boreholes plans comparing a uni-objective and a multi-criteria optimization approaches. In this work, the optimized location is considered the one that minimizes uncertainty translated by either the average local variance or the average width of 95% probability intervals of simulated values at unsampled locations. This methodology was applied using preliminary information obtained from previously executed boreholes using as variable the empirical rock mass classification system, Rock Mass Rating, in a Chilean deposit.This research is inserted in LNEC project named P2I-RockGeoStat and was partially funded by FCT (Fundação para a Ciência e Tecnologia, Portugal) in the scope of project PEst-UID/CEC/00319/2013, included in ISISE project UID/ECl/04029/2013 as well as the PhD grant SFRH/BD/89627/2012, and by the Chilean Commission for Scientific and Technological Research, through Project CONICYT PIA Anillo ACT1407.info:eu-repo/semantics/publishedVersio

Borehole plan optimization in rock masses using geostatistical simulation

The economical and safety aspects related with geotechnical engineering, in detail with prospecting works, are significant and increasingly complex. Therefore, optimizing costs that simultaneously guarantee the quantity and quality of information to characterize the rock mass are, nowadays, one of the most important factors in underground works. The borehole plans, normally defined using the knowhow of a professional, imply large costs in the geotechnical industry, thus this paper presents a new methodology allowing the optimization of such plans. This methodology allies geostatistical techniques (turning bands simulation to model rock mass properties like the Rock Mass Rating or RMR) with a stochastic global optimization algorithm, Simulated Annealing (SA). It relies on sparse information about RMR and randomly generates new points that intend to represent possible locations for additional boreholes. Furthermore, SA is adapted to perform the optimization of a set of points with different depth coordinates in order to represent the reality of the mechanical boreholes, where the information is obtained along the hole. Considering the number of additional boreholes to drill, SA finds a global solution minimizing an objective function, which aims at quantifying the uncertainty on RMR at locations without information. An application to a gold mine deposit located in Chile is finally presented in order to illustrate and validate the methodology.Agência de Desenvolvimento Económico do Chile através do projeto Innova Chile-CORFO 11IDL2-10630Comissão Científica e Tecnológica de Investigação chilena através dos projetos CONICYT / FONDECYT / REGULAR / N°1130085 e CONICYT PIA Anillo ACT 1407P2I-RockGeoStat do LNE

Adiposity indicators and cardiovascular risk factors in Azorean adolescents

This study was conducted to evaluate the association of adiposity indicators (body mass index, waist circumference and waist-to-height ratio) with cardiovascular risk factors in lean andobese Azorean adolescents.info:eu-repo/semantics/publishedVersio

Insulin resistance and its relation to adiposity, cardiorespiratory fitness and dietary intake among Azorean adolescents

Insulin resistance is an important compo nent in the development of metabolic syndrome and lifestyle-related diseases. The aim of the present study is to investigate the relationship between insulin resistance (IR), adiposity, cardiorespiratory fitness (CRF) and dietary intake among Azorean adolescents.info:eu-repo/semantics/publishedVersio

Use of markov chain in slope degradation prediction

Neste trabalho é apresentada uma proposta de modelo para a previsão da degradação de taludes de escavação em rocha. O modelo proposto foi desenvolvido recorrendo a cadeias de Markov, em particular a uma abordagem Markoviana sem memória. O modelo parte de um índice de qualidade que é atribuído ao talude em fase de exploração, o qual varia entre 1 e 5, e prevê a sua evolução ao longo do tempo. O modelo proposto caracteriza-se pela não necessidade do conhecimento do historial do talude, permitindo, assim, estimar o estado de condição de um dado talude ao longo do tempo, conhecendo apenas o seu estado atual. Esta característica representa uma mais-valia nas atuais condições de historial disponível sobre o estado de condição de taludes ao longo do tempo. De facto, o modelo proposto foi desenvolvido sobre uma base de dados sintética, a qual procurou refletir o mais fielmente possível a realidade. Os resultados obtidos, os quais representam a primeira iteração no desenvolvimento de um modelo de previsão do estado de condição de taludes durante a sua fase de exploração, mostram que será possível modelar o processo de degradação de taludes de escavação em rocha com relativa fiabilidade utilizando uma abordagem Markoviana.In this paper, a novel approach for rock slope degradation prediction is proposed based on a continuetime Markov chain. The proposed model is based on a quality index determined during a field inspection, which range between 1 and 5, and then predict the slope degradation over time. Taking advantage of the Markov property, that is the memoryless, the proposed model is able to predict the next state only based on the current state, not depending on the sequence of events that preceded it. This feature represents an important issue in the actual conditions, since currently there is no information related to the slope degradation process. Indeed, the proposed model is supported on a synthetic database that tried to simulate as well as possible the real slope degradation process over time. The achieved results, which represent a first iteration towards the development of a predictive model for rock slope degradation process during its exploration phase, show that the use of Markov chains can lead to reliable results.AdI – Innovation Agenc

Gestational weght gain and body mass index in pre-school children

To examine the association between gestational weight gain (GWG) and body mass index (BMI) in pre-school children.info:eu-repo/semantics/publishedVersio

Quality assessment system of rock slopes in exploitation phase

A alargada rede de infraestruturas viárias existente atualmente em Portugal, tem contribuído para uma crescente melhoria nas condições de mobilidade. De todas as componentes constituintes da rede, os taludes são os que apresentam um défice maior em termos de sistemas de avaliação de qualidade. Os sistemas e técnicas de avaliação de estabilidade de taludes rochosos possíveis de aplicar na fase de exploração são praticamente inexistentes. Neste trabalho é apresentado um sistema para a obtenção de um índice de qualidade aplicado a taludes predominantemente rochosos em meios rodoviários, e respetiva aplicação a um caso de estudo. Este índice permitirá estabelecer modelos de previsão de degradação do talude ao longo do tempo que integrarão uma ferramenta global de gestão sustentável de infraestruturas rodoviárias, atualmente em desenvolvimento. O sistema desenvolvido considera nove categorias de fatores, hierarquizados por grau de importância e influência através da atribuição de pesos. Estes pesos foram estabelecidos através do tratamento estatístico de um inquérito, distribuído a vários profissionais/peritos da área da geotecnia. O índice final do talude varia entre 1 e 5, correspondendo a taludes em muito bom e muito mau estado, respetivamente. Uma das principais vantagens é a de permitir identificar qual ou quais os fatores com maior relevância na qualidade do talude e, dessa forma, implementar medidas de manutenção e/ou de conservação de forma sustentada e eficaz no cumprimento de objetivos e, sobretudo, tendo por base a gestão dos recursos existentes.The extended network of road infrastructure currently existing in Portugal has contributed to a growing improvement in mobility conditions. Of all the constituent components of the network, the slopes are those with a greater deficit in terms of quality assessment systems. Systems and techniques for stability evaluation of rock slopes possible to apply in the exploitation phase are practically non-existent. This work presents a system to obtain a quality index for rock slopes in roads and its application to a case study. This index will allow establishing degradation models of the slopes over time, which will integrate a global tool for sustainable management of road infrastructures, currently under development. The developed system considers nine categories of factors, classified by degree of importance and influence by assigning weights. These weights were established through a statistical analysis of responses to a survey that was distributed to various professionals in the field of geotechnical engineering. The final index of the slope varies between 1 and 5, corresponding to slopes in very good and very bad state, respectively. One of its main advantages is that it allows identifying which are the factors with higher relevance on the quality of the slope and consequently implement more rationally the conservation and maintenance actions to achieve the objectives, and above all considering the management of the existing resources.AdI – Innovation Agenc