Development of underground mine monitoring and communication system integrated ZigBee and GIS

An automated underground mine monitoring and communication system based on the integration of new technologies is introduced to promote safety and health,operational management and cost-effectiveness.The proposed system integration considering Wireless Sensor Network(WSN) assisted Geographic Information System(GIS) enables to monitor and control underground mining applications from surface office.Based on the capabilities of WSNs,ZigBee network is adapted for near real-time monitoring,ventilation system control and emergency communication in underground mine.ZigBee nodes were developed to sense environmental attributes such as temperature,humidity and gases concentration;switching ON and OFF ventilation fans;and texting emergency messages.A trigger action plan for monitored attributes above normal and threshold value limits is programmed in the surface GIS management server.It is designed to turn the auxiliary fans on remotely or automatically in orange condition and sending evacuation messages for underground miners in unsafe(red) condition.Multi-users operation and 3D visualisations are other successful achievements of the proposed system for the underground monitoring and communication.

An improved bicubic imaging fitting algorithm for 3D radar detection target

3D ground-penetrating radar has been widely used in urban road underground disease detection due to its nondestructive,efficient,and intuitive results.However,the 3D imaging of the underground target body presents the edge plate phenomenon due to the space between the 3D radar array antennas.Consequently,direct 3D imaging using detection results cannot reflect underground spatial distribution characteristics.Due to the wide-beam polarization of the ground-penetrating radar antenna,the emission of electromagnetic waves with a specific width decreases the strong middle energy on both sides gradually.Therefore,a bicubic high-precision 3D target body slice-imaging fitting algorithm with changing trend characteristics is constructed by combining the subsurface target characteristics with the changing spatial morphology trends.Using the wide-angle polarization antenna’s characteristics in the algorithm to build the trend factor between the measurement lines,the target body change trend and the edge detail portrayal achieve a 3D ground-penetrating radar-detection target high-precision fitting.Compared with other traditional fitting techniques,the fitting error is small.This paper conducts experiments and analyses on GpaMax 3D forward modeling and 3D ground-penetrating measured radar data.The experiments show that the improved bicubic fitting algorithm can eff ectively improve the accuracy of underground target slice imaging and the 3D ground-penetrating radar’s anomaly interpretation.

Evaluation of fire smoke control in underground space

The main goal of the fire management strategy is to avoid people interaction with fire hazards,therefore several studies are carried out for optimal escape route planning as well as smoke management and mechanical ventilation design.Underground spaces are a special case of study due to their technical characteristics that create different fire spread conditions compared to conventional buildings.In this paper,a comparative study on the fire smoke propagation is carried out taking into account the use and performance of smoke mitiga-tion techniques.The Underground Hazardous Waste Management Repository of Lavrion Technological and Cultural Park in Greece,is selected as a case study to achieve the paper objectives.A Computer Fluid Dynamic software is used to simulate various fire scenarios based on the specific characteristics of the underground space.Parameters that have significant impact on evacuation procedure and human health such as visibility and carbon monoxide concentration are monitored.Finally,the results are presented and an evaluation method is proposed based on evacuation simulation results,in order to predict the impact of the smoke control design on the conditions inside the underground space.The results reveal that the ventilation shaft(passive system)offers an effective smoke control without any other combined control system and that the installation of smoke curtains,which are activated on time,offers significant improvement on smoke spread control extending the available egress time(ASET)in case of fire.