In underground tunnels or caverns, time-dependent deformation or failure of rock mass, such as extending cracks, gradual rock falls, etc., are a costly irritant and a major safety concern if the time-dependent damage of surrounding rock is serious. To understand the damage evolution of rock mass in underground engineering, an in situ experimental testing was carried out in a large belowground t...

Recent experimental work has shown that, when a vertical column of rock under large pressure is suddenly depressurized, the column can ‘explode’ in a structured and repeatable way. The observations show that a sequence of horizontal fractures forms from the top down, and the resulting blocks are lifted off and ejected. The blocks can suffer secondary internal fractures. This experiment provides...

Deformation modulus of rock mass has a significant role in the support design of an underground excavation. It is determined by expensive in-situ tests or by empirical models. Existing models for estimation of deformation modulus do not consider its stress dependence. Herein, data from several sources is used to develop a stress- (depth-) dependent relation for estimation of deformation modulus...

The evaluation of local stability of the tunnel surrounding rock mass with weak rock layer is very important for the economy and security of the tunnel construction. Based on the rock tunnel geological conditions in the construction, the finite element model of the tunnel surrounding rock mass stability analysis with weak rock layer is established in the article by selecting the ABAQUS program ...

It is of great importance to consider long-term stability of rock mass around the openings of underground structure, during design, construction and operation of the said structures in rock. In this context, three methods namely, empirical, analytical and numerical have been applied to design and analyze the stability of underground infrastructure at the Siah Bisheh Pumping Storage Hydro-Electr...

Successful application of a TBM in a project requires investigating both the ground conditions and the machine and backup system design features. Prediction of the machine performance is very important as it has a big effect on the duration of the project and the costs. In this respect, both penetration rate and advance rate must be estimated. Utilization factor, which depends on the type of op...

Drilling and blasting have numerous applications in the civil and mining engineering. Due to the two major components of rock masses, namely the intact rock matrix and the discontinuities, their behavior is a complicated process to be analyzed. The purpose of this work is to investigate the effects of the geomechanical and geometrical parameters of rock and discontinuities on the rock mass blas...

Laboratory tests were performed on 54 large size specimens of jointed rock mass under uniaxial loading conditions. Based on this experimental study, a methodology has been suggested to estimate strength and tangent modulus of rock masses through a weakness coefficient. The methodology involves mapping of joints in the field and laboratory testing of intact rock specimens to arrive at rock mass ...