As well as flow through joints, 3DEC 5.2 is capable of simulating fluid flow through the blocks or the matrix (i.e., between the joints). It is assumed that the blocks represent a saturated, permeable solid, such as soil or fractured rock mass.
Cable elements in 3DEC may be assigned a tensile yield force limit and an axial rupture strain in order to simulate cable rupture. 3DEC can also simulate the shearing resistance along the cable length between the grout and either the cable or the host material.
Calibration of geomechanics models using microseismic data is key to creating reliable predictive tools. This presentation reviews the geomechanical model used for: stress characterization, microseismic modeling to assess the risk associated with faults activation and induced seismicity, and evaluation of designs and operational strategies. Both hydraulic fracturing and hydro-shearing of discrete fracture network were important components of stimulation of EGS and zonal isolation can play a key role in effective stimulation of an EGS along the entire length of the horizontal well.
The Fabian orebody is a non-daylighting iron orebody in the LKAB Malmberget Mine in northern Sweden. During 2010, a prognosis of the cave development in the Fabian area was developed, based on compilation and analysis of all available material. In March 2012, a new cave crater formed on the ground surface above the Fabian orebody, similar to what was predicted. The prognosis is compared with observations of the caving and the differences and implications quantified. A program for continued monitoring of mining-induced deformation in Malmberget is also described and a criterion for allowable mining-induced surface deformations is proposed.
Field monitoring programs (e.g., convergence measurements and stress measurements in the support system) play an important role in following the response of the ground and of the support system during and after excavation. They contribute to the adaptation of the excavation and support installation method and the prediction of the long-term behavior. In the context of the Lyon–Turin link project, an access gallery (SMP2) was excavated between 2003 and 2010, and a survey gallery (SMP4) has been excavated since 2017.