| Seepage considerations are a key element in analyzing the geotechnical stability performance of soil and rock slopes in open pit mines. Two effects need to be considered: the quantity of flow (operational) and the reduction in the soil/rock mass shear strength resulting from water pore pressures within the rock and/or soil masses. Groundwater flow through soil/rock masses is mainly controlled by rock mass geometry and discontinuities, material properties (i.e. hydraulic conductivity, permeability) and geological characteristics of the rock mass. All of these factors have large uncertainties because soil/rock masses are usually heterogeneous and anisotropic.; The objective of this thesis is to develop practical equations and methodologies to estimate the quantity of flow and distribution of pore pressures within the slopes for analyzing the geotechnical slope stability of open pit mines. Plane and axysimmetric closed form solutions and finite element numerical models are utilized to estimate the quantity of seepage, phreatic surfaces and the distribution of pore pressures for different slope geometries and boundary conditions. Considering the large uncertainty associated with the hydraulic conductivity, an attempt is made to estimate the directional variation of this parameter according to fracture geometry. |
