Numerical Methods By K Das Pdf
9.1.3. problem formulation. the problem of finding the rock mass mechanical properties near the drift of a secondary stope was tackled using the dynamic flac3d finite element software code. over the past few years, several dynamic flac3d finite element codes have been developed (e.g.bohlin etal., 2012; gong, 2008; madar, 2007; madar, ercole, etal., 2007; renno & yang, 2008; yang, gong, & renno, 2007), but none of them have been used to study secondary stoping at any scale to date. one of the primary difficulties in using these numerical codes to model the mechanics of the rock mass is the requirement of having a 3d mesh (surface) of the stope drift. this requirement can be overcome by using laser scanning to determine the 3d surface of the stope drift (ruppert etal., 2009; toth, 2002; toth, charvat & zhang, 2001; ruppert etal., 2009). unfortunately, traditional scanning methods cannot be used for subterranean applications. the primary reason is that the size of the sampling volume, which can be captured by a passive laser scanner, is relatively small. another reason is that the measurement is static. layers under compression that are in contact with the scanning volume, will cause the data to be distorted. to obtain good surface data, a repetitive scanning sequence was initiated on the stope at several locations along the drift. unfortunately, the volume of scanned data and the average time taken to scan at each location are insufficient to allow flac3d simulations to predict the stoping process of the secondary stope drift.
numerical methods by k das pdf