scholarly journals Evaluation of stress state in rock mass surrounding underground structures of waterworks

2019 ◽  
Vol 262 ◽  
pp. 012017
Author(s):  
LN Gakhova
Keyword(s):  
Rock Mass ◽  
Stress State ◽  
Underground Structures

Comparison of the Stress-State Level for the Inhomogeneous Rock Mass with a Spherical Cavity in the Stationary and Non-Stationary Temperature Conditions

2018 ◽  
Vol 931 ◽  
pp. 78-83 ◽  
Author(s):  
I.I. Frolova ◽  
Vladimir Igorevich Andreev
Keyword(s):  
Rock Mass ◽  
Stress State ◽  
Spherical Cavity ◽  
State Level ◽  
Temperature Fields ◽  
Underground Structures ◽  
Self Heating ◽  
Temperature Conditions ◽  
Inhomogeneous Rock ◽  
Properties Of Materials

The paper contains comparative analysis of solutions for problems with the rock-mass stress-strain state in the vicinity of a spherical cavity for the case of stationary and non-stationary temperature conditions. Such a cavity was created by blasting and further was used as storage for products that tend to self-heating. So, both problems considered the process inhomogeneity of the rock mass soil and the inhomogeneity caused by an action of various high-temperature fields. The results obtained prove the significant impact of the inhomogeneity on the stress state of the rock mass for any types of temperature conditions. The development of methods for calculation of underground structures that would fully consider the conditions of their creation and operation as well as actual properties of materials is one of crucial areas in structural mechanics.

Residual strength of underground structures in service

2016 ◽  
Vol 53 (6) ◽  
pp. 988-999 ◽  
Author(s):  
Taous Kamel ◽  
Ali Limam ◽  
Claire Silvani
Keyword(s):  
Stress State ◽  
Residual Strength ◽  
Underground Structure ◽  
Numerical Approach ◽  
The Finite Element Method ◽  
Underground Structures ◽  
Weathering Processes ◽  
Working Face ◽  
Metro Tunnel ◽  
Loss Of Strength

Old tunnels suffer from deterioration and it is necessary to assess their residual strength to properly organize their repair and strengthen them. The stress state of underground structures evolves over time, firstly because of the advancement of the working face during construction, then due to gradual changes in soil properties and mechanical properties of materials composing the infrastructures, such as reduction of cohesion, loss of strength and (or) stiffness, etc. These changes are caused by combined actions such as creep and (or) weathering processes as well as the appearance of cracks that induce redistribution of stresses and therefore strains. This study investigates tunnels and galleries of the Paris underground. Macromodeling based on the finite element method allows consideration of different scenarios of tunnel-lining deterioration, specifically at the extrados of the galleries or tunnels. To understand changes in the stress state, and also damage occurrence and associated redistributions (stress and strain), it is necessary to model the delayed deformations. To model the infrastructure behavior, a time-dependency approach has been chosen. This approach can quantify the damage and predict the residual strength of this type of underground structure. An elastic–viscoplastic constitutive model with strain-softening is used to reproduce the appearance of the degraded zones and their behavior. The results obtained with the numerical approach reproduce Paris metro tunnel behavior, corroborate geoendoscopy results, clarify their interpretation, and improve the management of infrastructure repairs.

scholarly journals Determination and quality classification of rock mass of the Diatomite mine, Algeria

2021 ◽  
Vol 1 ◽  
pp. 17-24
Author(s):  
Abdessattar LAMAMRA ◽  
◽  
Dmitriy Leonidovich NEGURITSA ◽  
Samir BEDR ◽  
Ariant A. REKA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Underground Mining ◽  
Physical And Mechanical Properties ◽  
Friction Angle ◽  
Classification Systems ◽  
Natural Phenomenon ◽  
Underground Structures ◽  
Dilatancy Angle ◽  
Mining Work

Reserch relaevance. Most ground movements are generally due to rock instability, this natural phenomenon poses a risk to humanity. The properties of the rock mass directly influence the type of movement especially in underground structures. Research aim. Our goal is to characterize and classify the rock mass of diatomite from the sig mine using geomechanical classification systems such as the RQD and RMR in order to determine the quality of the rocks in the sig mine Western Algeria from the determination of the physical and mechanical properties. Methodology. In this article, the characterization analysis of the diatomite rock mass of the sig mine was carried out. First, determinations of the physical properties and carried out the triaxial test to determine the mechanical properties (young’s modulus, the friction angle, the dilatancy angle, the cohesion, the poisson’s ratio). Secondly to classify the deposit and give a recommendation to avoid stability problems. Research results. The results from physical and mechanical analyzes, it can be said that the nature of the rock present in the diatomite (underground mine) does not have enough resistance. Conclusion. Our study definitively proves that the rock mass of sig diatomite is of very low quality and it will be very dangerous for the underground mining work of the mine especially in places where the mineralized layer is very deep. And we suggest to replace the mining technique room and pillar currently used in the diatomite mine and put another mining method which includes roof support system to ensure the safety both of the miners and the equipment.

Application of Numerical and Block Geomechanical Modelling to Determine Parameters of Large-Section Chambers

2021 ◽  
pp. 127-131
Author(s):  
M.A. Sonnov ◽  
A.V. Trofimov ◽  
A.E. Rumyantsev ◽  
S.V. Shpilev
Keyword(s):  
Rock Mass ◽  
Strain State ◽  
Stress And Strain ◽  
Underground Structures ◽  
Geomechanical Model ◽  
Principal Stresses ◽  
Mine Support ◽  
History Of ◽  
Crushing Plant ◽  
Ore Pass

The study is exemplified by complex workings of a main ore pass that include a variety of underground structures, usually with unique dimensions which depend on the function and size of the equipment placed. The technical solutions for the underground crushing plant and associated structures envisage construction of chambers with the height of up to 35 m and the width of up to 20 m at the depths exceeding 800-1000 m. Such conditions call for a closer attention to be paid to the mine support parameters, especially the bolting depth. A block geomechanical model was designed in the Micromine Mining Software for the rock mass of the new main ore pass. Geotechnical boreholes logs and results of physical and mechanical rock tests were used as the input data for the model. Four domains were identified in the block geomechanical model for subsequent numerical modelling. A 3D model of the stress-and-strain state of the rock mass was made using the CAE Fidesys software based on the Micromine wire-frame model of the main ore pass. The history of the rock mass incremental loading was reconstructed for correct simulation of its stress-and-strain state. Prior to the excavation, the rock mass is pre-stressed by the weight of the rock strata. The excavation phase was then simulated in the stepwise manner. An array of points with the values of maximum principal stresses was downloaded from the numerical model post-processing program and interpolated into the block geomechanical model to refine the SRF parameter of the Barton's Q rating. Based on the obtained Q values, the mine support parameters for chambers were determined using the Barton, Hutchinson and Potvin empirical methods.

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