Aplicação de ondas elementais no estudo de vibrações geradas por desmontes de rochas
Application of signature waves on the study of vibrations generated by rock blasting
Paulo José Costa Couceiro Júnior, Eraldo Florêncio da Silva Júnior
Resumo
A aplicação de cargas explosivas sequenciadas para a escavação e fragmentação de rochas constitui uma operação unitária essencial na mineração. Entretanto, a liberação de energia resultante desse processo gera, entre outros fenômenos, um evento sísmico adverso que pode condicionar a viabilidade do projeto. Distintas técnicas de controle e previsão dos níveis de vibrações foram desenvolvidas nas últimas décadas, tais como a aplicação de ondas elementais na modelagem sísmica resultante de desmontes de rochas. A superposição de ondas individuais na conformação de histórias temporais das velocidades de partícula permite a verificação de distintos aspectos do desmonte, tais como o efeito dos tempos de retardo e sequenciamento das cargas explosivas, orientação da propagação das ondas sísmicas, e incertezas envolvidas no projeto, entre outros. Neste trabalho, um modelo de ondas elementais, baseado em variáveis estocásticas compatíveis com simulações Monte Carlo, é apresentado com o intuito de prever os níveis de vibrações mais prováveis de um desmonte de rochas. Finalmente, esta metodologia é exemplificada em um exemplo de aplicação, cujo níveis das vibrações necessitavam medidas preditivas mais fiáveis para garantir a viabilidade da obra.
Palavras-chave
Abstract
The application of sequential explosive charges for excavation and fragmentation of rocks constitute an essential unit operation in mining. However, the liberation of energy resulting from this process creates, within other phenomena, an adverse seismic event that may condition the viability of the project. Different control and predicting vibration techniques have been developed in the last decades, such as the application of signature waves in modeling vibrations resulting from rock blasting. The superposition of individual waves for the conformation of particle velocities time-histories allows the verification of different blasting aspects, such as the effect of delays and sequence of detonation, orientation of the propagation path of waves, and uncertainties involved in the project, and others. In this work, a stochastic signature hole model is presented together with Monte Carlo simulations technique, which permits the prediction of the most probable vibration levels of a given blast. Finally, this methodology is illustrated in an example of application whose vibration levels required more reliable predictive measures to ensure the viability of the work.
Keywords
Referências
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Submetido em:
27/12/2019
Aceito em:
13/09/2020
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