The stability evaluation of rock masses surrounding large underground caverns under earth-quake effect is an alive and important subject. Under earthquake effect, the mechanical re-sponse characteristics of rock masses surrounding underground caverns are remarkably differ-ent from those under excavation unloading effect. Therefore, it is not appropriate to directly use the methods and criterions that are commonly adopted in static analysis to evaluate the behav-iors of rock masses under dynamic condition. A series of indexes and relevant criterions are included in the system. The indexes of relative displacement, peak stress, depth of damage zone, and rock support stress are proposed as a whole evaluation system. The evaluation sys-tem is then validated in a large underground cavern subjected to earthquake effect. It is con-cluded the system is effective. The presented methods and findings are hoped to provide useful references for other rock caverns with similar stability concerns.

Groundwater flow through fractured rocks was recognized as an important problem connected to several scientific and engineering geological fields, including hydrogeology, rock mechan-ics, geotechnical engineering. Fluid flow in rock masses plays an important role in many geo-logical hazards such as environmental risk. Fractured media are very heterogeneous and the hydraulic and geomechanical properties are strongly dependent on the rock mass spatially varying geometrical parameters. This makes the study of groundwater flow a considerable challenge for modeling purposes in the frame of environmental pollution, especially consider-ing that fractures may act as preferential drainage paths, thus accelerating the transport process. This study aims at shedding light, through a numerical simulation, on the influence played by major fractures on the groundwater circulation in a carbonate aquifer. The numerical model was built in a Q-GIS environment through the FREEWAT plug-in, by considering different scenarios that model the interaction between pumping activity and fracture field.

Rockfall reinforced earth embankments (RPE) are widely adopted defence structures against rockfall, particularly effective for high-energetic or frequent block impacts. Existing design approaches often involve simplifications, as RPE resisting mechanisms during impact has been not yet completely investigated. This study investigates the RPE response at the impact through a series of FEM analyses. Geophysical and plate load tests on an existing RPE are used to calibrate the soil constitutive law of the numerical model. The results of the huge campaign of sensitivity analyses, herein presented, allow to determine the mechanical and geometrical parameters most affecting the structural behaviour.

For underground rock engineering, laboratory testing is performed to obtain objective in-formation about the rock behaviour under compressive or compression-induced tensile fields through biaxial, true triaxial and indirect tensile tests. The ISRM-suggested methods for laboratory testing advocate the implementation of axial loading or strain rates that de-pend on laboratory parameters that are not or only rarely related to in-situ conditions. Near an excavation wall, the tangential strain and therefore strain-rate decreased with increasing distance from the wall. Due to the complexity of physically assembling a multi-platen ser-vo-controlled machine, the influence of uniform and non-uniform tangential strain rate distributions on the mechanical behaviour of brittle materials is rarely tested and is as-sessed here by using the software PFC2D. The mechanical responses for loading with two tangential strain patterns or strain-rate distributions are compared in terms of cracking pat-tern, stress-strain curves, bulking strain and related displacement at the excavation surface.