Study on the Shrinkage Error of Similar Material Simulation Experiment
Shrinkage error will impact the results obtained from the observation data when studying subsidence by the method of similar material simulation experiment. Using digital industrial close-range photogrammetry system in the experiment, high-precision observational data is collected. By comparative analysis on the subsidence of the points at different locations, we obtained the distribution law of shrinkage subsidence and horizontal movement which has great significance for the study on how to reduce the shrinkage error effectively.
Prediction Analysis of High Class Highway Influenced by Surface Residual Deformation in Mining Zones
The case that high class highways are constructed in influenced regions by mining is common.The main principle to determine the stability of roadbed and to analyse the influence degree is the surface deformation caused by mining.The mining surface deformation can be divided into continuous and noncontinuous displacement deformation.Theory method is given to predict the displacement deformation caused by surface residual subsidence under continuous deformation conditions. Different influence zones are divided by the contour figure of surface residual deformation.According to the characteristics of displacement deformation of the influenced zones,a method is given to determine resisting deformation structure of roadbed and pavement fitting with displacement deformation of influenced zones by mining.
Investigation of pillar failure in the Emaswati Coal Mine, Swaziland
Abstract The causes and mechanisms of pillar failure in a section at the Emaswati Coal Mine in Swaziland are discussed. The study indicates that there exists an intricate relationship between the local geology and ground instability that needs to be addressed if future pillar failure is to be avoided. The conclusions are mainly based on extensive in-mine investigations and finite element computer modeling using the mechanical properties of mine roof, coal, and floor. The study has indicated that pre-mining failure, coupled with the possible loss of strength due to the heating of the coal seam (which was caused by the hydrostatic emplacement of dolerite dykes and sills) adversely affected the bearing capacity of subsequent coal pillars.