After the mass closures of entire coal mine districts in Europe at the end of the last century, a new phenomenon of surface movement was observed—an upward movement.Although most surface movement(i.e., subsidence) oc...After the mass closures of entire coal mine districts in Europe at the end of the last century, a new phenomenon of surface movement was observed—an upward movement.Although most surface movement(i.e., subsidence) occurs in the months and years after mining by the longwall method, surface movement still occurs many decades after mining is terminated.After the closure and flooding of underground excavations and surrounding rock, this movement was reversed.This paper focuses on quantifying the upward movement in two neighboring coal mines(Winterslag and Zwartberg, Belgium).The study is based on data from a remote sensing technique: interferometry with synthetic aperture radar(INSAR).The results of the study show that the rate of upward movement in the decade after closure is about 10 mm/year on average.The upward movements are not linked directly to the past exploitation directly underneath a location.The amounts of subsidence at specific locations are linked mainly to their positions relative to an inverse trough shape situated over the entire mined-out areas and their immediate surroundings.Local features, such as geological faults, can have a secondary effect on the local variation of the uplift.The processes of subsidence and uplift are based on completely different mechanisms.Subsidence is initiated by a caving process, while the process of uplift is clearly linked to flooding.展开更多
Although most subsidence occurs in the months and years after mining by the longwall method, surface movement is still occurring many decades after the mining. The aim of the study is to quantify the long term behavio...Although most subsidence occurs in the months and years after mining by the longwall method, surface movement is still occurring many decades after the mining. The aim of the study is to quantify the long term behavior. Satellite data(radar-interferometry) were analyzed to study an area of about 2 km^2 during the 18 years following the closure of the underground infrastructure and the flooding of the underground workings and rock mass. It was observed that, on average, a residual downward movement took place till 7–12 years after the closure, followed by a clear uplift. However, the first signs of an uplift occurred in certain sub-areas 3–4 years after the closure. Zones within the area studied were identified with either larger or smaller movements. However, the spatial variation of the surface subsidence or uplift could not be directly explained by the characteristics of mining.展开更多
This paper covers the entire lifetime of an underground coal mine,including the start-up of the mining operations and the period after the closure and sealing of the underground workings.Measurements of the vertical s...This paper covers the entire lifetime of an underground coal mine,including the start-up of the mining operations and the period after the closure and sealing of the underground workings.Measurements of the vertical surface movement are presented for three neighbouring mines in the Belgian Campine coal basin,where the longwall mining method was applied.First,the monitoring of the initial phase showed that the impact of the first panel was smaller than the impacts of the following two neighbouring panels.When the second panel was mined,a change in the induced surface tilt was observed in the immediate proximity of the panels.Second,data for a transect with a length of about 2.5 km were presented,covering a total time of 54 years,of which the first 31 years were during the active life of the mine.Average subsidence rates of up to-0.3 m/year were observed.After the mine was closed and the pumping facilities were stopped,the average uplift rate was situated mostly between 4 and 16 mm/year,but a value of 141 mm/year also was measured.Thirty years after closure,the upward movements are still occurring.Third,the phase of uplift is analyzed in more detail over a full north–south transect.A clear narrow maximum was observed for the uplift,corresponding to a total vertical movement of 0.2 m over approximately an 18-year period.All these phases are relevant,for example when analysing damage to buildings and infrastructure.Damage becomes visible when the cumulative movement and loading exceed critical limits and not necessarily when the largest rate of movement is observed,for example.展开更多
文摘After the mass closures of entire coal mine districts in Europe at the end of the last century, a new phenomenon of surface movement was observed—an upward movement.Although most surface movement(i.e., subsidence) occurs in the months and years after mining by the longwall method, surface movement still occurs many decades after mining is terminated.After the closure and flooding of underground excavations and surrounding rock, this movement was reversed.This paper focuses on quantifying the upward movement in two neighboring coal mines(Winterslag and Zwartberg, Belgium).The study is based on data from a remote sensing technique: interferometry with synthetic aperture radar(INSAR).The results of the study show that the rate of upward movement in the decade after closure is about 10 mm/year on average.The upward movements are not linked directly to the past exploitation directly underneath a location.The amounts of subsidence at specific locations are linked mainly to their positions relative to an inverse trough shape situated over the entire mined-out areas and their immediate surroundings.Local features, such as geological faults, can have a secondary effect on the local variation of the uplift.The processes of subsidence and uplift are based on completely different mechanisms.Subsidence is initiated by a caving process, while the process of uplift is clearly linked to flooding.
文摘Although most subsidence occurs in the months and years after mining by the longwall method, surface movement is still occurring many decades after the mining. The aim of the study is to quantify the long term behavior. Satellite data(radar-interferometry) were analyzed to study an area of about 2 km^2 during the 18 years following the closure of the underground infrastructure and the flooding of the underground workings and rock mass. It was observed that, on average, a residual downward movement took place till 7–12 years after the closure, followed by a clear uplift. However, the first signs of an uplift occurred in certain sub-areas 3–4 years after the closure. Zones within the area studied were identified with either larger or smaller movements. However, the spatial variation of the surface subsidence or uplift could not be directly explained by the characteristics of mining.
基金There were no external sources of funding for conducting this research.
文摘This paper covers the entire lifetime of an underground coal mine,including the start-up of the mining operations and the period after the closure and sealing of the underground workings.Measurements of the vertical surface movement are presented for three neighbouring mines in the Belgian Campine coal basin,where the longwall mining method was applied.First,the monitoring of the initial phase showed that the impact of the first panel was smaller than the impacts of the following two neighbouring panels.When the second panel was mined,a change in the induced surface tilt was observed in the immediate proximity of the panels.Second,data for a transect with a length of about 2.5 km were presented,covering a total time of 54 years,of which the first 31 years were during the active life of the mine.Average subsidence rates of up to-0.3 m/year were observed.After the mine was closed and the pumping facilities were stopped,the average uplift rate was situated mostly between 4 and 16 mm/year,but a value of 141 mm/year also was measured.Thirty years after closure,the upward movements are still occurring.Third,the phase of uplift is analyzed in more detail over a full north–south transect.A clear narrow maximum was observed for the uplift,corresponding to a total vertical movement of 0.2 m over approximately an 18-year period.All these phases are relevant,for example when analysing damage to buildings and infrastructure.Damage becomes visible when the cumulative movement and loading exceed critical limits and not necessarily when the largest rate of movement is observed,for example.
