The causes and prevision of mine subsidence in lesser Himalayas, Abbottabad.

Numerous Impulsive mine collapses induced by shallow partial mining in the Cambrian Abbottabad formation have caused fatalities, significant property loss and brought harmful results to the environment. Mining subsidence is therefore needed to be monitored on all accounts during mining operations in this area. Based on a long history of soapstone mining in Sherwan, a generic approach is presented in this paper for investigating subsidence related phenomena in the area. This paper demonstrates a time prevision for the future subsidence using an empirical modelling approach EMA. 20 underground drift and shaft mines located in the Sherwan North-West Abbottabad, Pakistan have been studied using EMA. Empirical modelling formula, validated by Distinct Element code UDEC has been used to predict the time of subsidence of these mines. This approach is a factor of width, height and depth of excavation of a mine and it can be applied to area where mines are truly restricted to one locality e.g. Sherwan. The calculated statistical data unconcealed the current state and predicts time for future subsidence of Khanda Khau, Bandi Nikra and Chellether mines within Sherwan. Mines other than these three localities are mostly safe and stable. The major causes of mine subsidence in the area includes both natural and man-made factors which are briefly described in this paper. [ABSTRACT FROM AUTHOR]