Fault reactivation, an example of environmental impacts of groundwater rising on urban area due to previous mining activities
Yu, M.H.; Jefferson, I.F.; Culshaw, M.G.. 2007 Fault reactivation, an example of environmental impacts of groundwater rising on urban area due to previous mining activities. In: 11th Congress of the International Society for Rock Mechanics, Lisbon, Portugal, 9-13 July 2007. London, UK, Taylor and Francis, 41-45.Before downloading, please read NORA policies.
Groundwater rising phenomena have been reported in many circumstances, and the mechanism of rising groundwater varies according to hydrological and hydrogeological conditions. Groundwater rising can cause various geohazards which can have serious impact on environment as well as society. Fault reactivation is one such geohazard example associated with rising groundwater. The case in the Durham Coalfield is one of the cases where many recent fissurings can be found and are considered to be the result of fault reactivation accompanied with rising groundwater after cessation of coal mining over the region. The aim of this research is to estimate past and present hydrogeological condition in the Durham Coalfield enabling the evaluation of the influence of rising groundwater phenomenon on the urban and rural environment. Hence, in this research, the hydrogeological condition of the Durham Coalfield is evaluated. The past and present condition is discussed with the available groundwater data, and the future trend has been simulated, by a numerical hydrogeological model using a 3-D groundwater code MODFLOW. The result of hydrogeological model for past, present and future conditions show that general groundwater level in the Durham Coalfield has been rising for the last a few decades. The discussion of this research shows that groundwater rising can cause pore water pressure to increase, resulting in reducing shear strength of pre-existing fault, which has been shown by some case histories. In addition it is found that some fault directions enables slippage and some faults have experienced fault reactivation. Therefore it is concluded that this reduction in fault strength caused by change in hydrogeological condition of the Durham Coalfield enables a pre-existing fault to be reactivated when they exist in a direction of slip with respect to present regional stress direction.
|Item Type:||Conference or Workshop Item (Paper)|
|Programmes:||BGS Programmes > Physical Hazards|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||24 Mar 2010 08:49|
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