![]() ![]() The soil used in the physical model is Fontainebleau sand. The aim of the research is to study the soil-structure interaction effect of large vertical displacement owing to underground mines. ![]() The paper presents a new large small-scale physical model (6 m3) for studying the damage to structures owing to underground movements: settlement, subsidence and sinkhole. ![]() The results obtained in the field tests demonstrate the effectiveness of the motion control systems and validate the UX-1 Robot platform as capable of performing the complex task of navigation and control in flooded mine environments. Afterwards, a full exploration and geo-scientific data collection mission is presented, where all of the motion control systems are active simultaneously during a deep dive to more than 100 m. Several experiments are shown which demonstrate the successful operation of the motion control systems in individual performance tests. The control method implemented is based on a state Feedback Linearization algorithm, previously tested and validated in a controlled water tank environment. These field experiments have been performed to test and validate the motion control systems of the underwater explorer robot (UX-1), which are: a variable ballast system for buoyancy control, a variable pitch system for pitch control, and a propulsion system for depth and heading stabilization. In this work, we present the results of a series of field trials conducted with an underwater vehicle in the increasingly complex underwater environments of the Kaatiala mine in Finland, the Idrija mine in Slovenia, and the Urgeiriça mine in Portugal. As a prospective, in order to better understand the seismic hazard, more accurate observations of the seismicity, mechanical parameters and water level changes in the seismically active zone are required to improve the understanding and the interconnection between these factors. Despite the general understanding of the mechanism behind the seismicity, the maximum magnitude of the events that can be triggered is at this moment is difficult to quantify and predict due to limitations of available data. Spatial and temporal characteristics of observed seismic events and multiplet and repeater occurrences provided a clearer image of the active geological structures and allowed a preliminary interpretation of possible mechanisms affecting the initiation and driving of the repeating or after-shock like behavior of seismic events, based on comparison with available hydrological data. All results are in favour of the origin of the seismic sources on the fault below the mine. The seismicity clustering behaviour was indicated by the new seismic catalogue 2014-2017, which was further analysed more thoroughly. The new developed detection and location methodology adapts the full waveform-based method BTBB by Poiata by overcoming the challenges of the sparse seismic monitoring network, and includes a novel approach for noise removal from continuous dataset as well as location quality-based classification system. Thesis work focused on questions concerning precise identification of seismic source origin evaluating two hypothesis, determination of the mechanism behind the seismicity, link between seismicity and the hydrogeological system, as well as improving of the detection and location of microseismicity with a sparse network. The knowledge on the origin and the triggering mechanisms of the seismic activity in Gréasque and Regagnas sector is the key for seismic hazard assessment of the entire Gardanne basin. Seismic activity in Gardanne mine seems to originate from an interaction between rocks and fluids, as spatio-temporal distribution of events suggests the link with intense rainfall events as well as the active pumping. As a case study, this thesis focused on the abandoned, flooded coal mine in Gardanne, France, which has been experiencing significant post-mining seismicity problems. In general, mechanisms of observed seismicity in flooded, post-mining districts have been poorly understood. When mines are abandoned, groundwater pumping systems are usually stopped and the water which progressively fills the remaining voids can affect the mechanical stability of underground structures. The closure of mines and post-mining management nowadays present a major challenge as the problems that arise can greatly concern public security.
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