Contribution to the modelling of jointed rock mass hydromechanical behaviour

摘要

We define a methodology of network characterization in order to determine geological model that will support a hydromechanical modeling. This methodology is developed on the experimental site of Coaraze which is a fractured limestone aquifer. The multi-scale characterization allows the distinction of a few decametric discontinuities limiting zones including metric discontinuities. Discontinuities with extension of tens meters correspond to faults and to a few major bedding planes. The fault planes are included in a 40 to 60 cm thick zone with centimetric cracks. Zones include a network of metric fractures with low shear displacement and of pluri-metric bedding planes. Experiences of piezometric head variations show a typical double-permeability behaviour characterizes by the difference between drains (rapid stabilization of pressure) and blocks (time lag of the hydraulic response). It appears that drains correspond to the decametric discontinuities and blocks to the zones with only centimeter to meter scale joints and bedding planes.