· Rock burst phenomenon may more easily occur for hard rocks under triaxial unloading conditions. Abstract Triaxial compression tests were conducted on fine-to-medium–grained granite specimens, with initial confining pressures of 10, 20, 40, and 60 MPa, under various loading and unloading stress paths.
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· Spalling and slabbing are typical brittle hard-rock local failure modes. In the oblique ovaloid tunnel, the final V-shaped layer-by-layer failure zone only arises at the tunnel top along the σ min direction (Fig. 26 b and Fig. 27). The AE events are concentrated at
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The method of RLSD with parent rock high similarity and surface authenticity with varying angles and JRC is proposed. • With the increase of β, the σ c, ε p, E of RLSD show a V-shaped trend and the shear failure increases and then decreases.The empirical formula
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· Hard Rock Park boasted rides themed around Led Zeppelin songs and acid trips, but it closed after just five months, amid the 2008 financial crisis. Ten years later, we visited the abandoned site
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· RELATED: Engineers who responded to 9/11 helping with New Orleans hotel collapse. “But it’s hard to say, because we don’t know what caused the failure,” she said. H.J. Bosworth, a New
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· numerical method of spalling failure are proposed. This numerical method can not only simulate the. spalling failure zone formed by tangential compressive stress concentration after excav ation
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· Due to geological and geotechnical uncertainties in the design of tunnels and underground constructions, ML techniques can be used to accurately predict and forecast the rock mass and underground
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Failure and strength. Failure may be defined as the stress condition at which the solid either starts to flow or break. This stress condition thus defines the maximum stress or stress difference that the solid can sustain, that is, its load-bearing capacity. When the failure of the solid is through fracture formation, the failure is brittle.
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· These include ineffective hard rock canyon excavation, hard top board failure, over-the-top hard rock rupture, and other problems [4] [5][6]. These issues significantly limit the efficiency of
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· Based on the rock failure phenomenon and combined with the experience of predecessors, a classification criterion was established for the evaluation of rock burst tendency for hard rocks, as shown in Table 4.
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· Hard rock often performs as brittle failures, such as cracking, spalling, and rockburst, induced by excavation in deep underground engineering. To understand the effect of the minimum principal…. Expand. 39.
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· The phenomenon of toppling deformation and failure is ubiquitous in layered anti-dip rock slope. In this paper, the development process of toppling deformation and failure is simulated by similar tests. In the test, the rock test model of soft-hard interbedding is established by the law of similarity. Based on the test results, the process
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· This study can supply useful references to the study of failure properties of hard rock under complex stress states. | Rockburst disasters occurred at Paoma mountain No. 1 tunnel.
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· As a common disaster in deep-buried hard rock engineering projects, rock-bursts seriously threaten the safety of workers and facilities. Water infusion in rock mass before excavation is usually used for rock-burst prevention. To reveal the underlying mechanism of rock watering for rock-burst inhibition, a series of uniaxial compression
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· In deep hard rock engineering, the rock failure degree varies under different stress states. In order to study the stress test accuracy of rocks under different stress states, thirty-five loading conditions were set up. The stress magnitude value is between 10 and 50
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· Mechanical analytical theory of the hard rock fracturing process in deep engineering, including the 3D nonlinear failure criterion, stress-induced ductile-brittle anisotropic model, rock failure degree index, local energy release rate (LERR) index,
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· In the study of fracture mechanisms of the THR, Xu et al. put forward the theoretical failure model of thick and hard rock strata to calculate the rock failure laws in Yangliu Coal Mine, Huaibei
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· The estimation of rock strength is one of the most important basic requirements in rock engineering design and analysis. In this study, six different data-driven machine learning (ML) models to predicate the major principal stress ( $${\\sigma }_{1}$$ σ 1 ) at the failure of intact rock material under the polyaxial (true triaxial) stress condition
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Slabbing failure and strain rock burst are the main failure patterns during the excavation and construction phases of deep tunnels in hard and brittle rock, which
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· Hamediazad, F. & Bahrani, N. Simulation of hard rock pillar failure using 2D continuum-based Voronoi tessellated models: The case of Quirke Mine, Canada. Comput. Geotech. 148 , 104808 (2022).
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· To explore the failure precursors of hard rock, a series of triaxial loading and unloading experiments were carried out on sandstone sample using the acoustic emission systems. The extreme-point
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· In most numerical simulations of hard rock pillars using discontinuum methods, the modelled pillars were monotonically loaded from zero stress until failure (e.g., Li et al., 2019, Sinha and Walton, 2021a), and therefore the impact of mining-induced stress
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· The existence of soft and hard rock interbedding causes the subsidence induced sliding and wedge failure of anti-dip layered slope with stable low dip. Underground excavation makes the anti-dip slope with weak layers to subside, which makes it easy to form a shear slip surface inside the rock mass.
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: Yang Liu, Cai-Ping Lu, Cai-Ping Lu, Heng Zhang · Failure often causes casualties, equipment damage, and delays, bringing significant potential safety hazards to the construction of deep hard rock projects
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· Abstract. An enhanced cohesion weakening and friction strengthening model is proposed to simulate the progressive failure of hard rock pillars using two- and three-dimensional finite difference analysis. The documented behavior of 85 pillars in two mines was used for model validation. The numerical models successfully separated
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· Spalling is a typical brittle failure phenomenon of hard rock in deep caverns under high geostress. In this study, key issues are systematically studied concerning the spalling failure of deep hard rock caverns. First, the prismatic rock specimens with small thicknesses (i.e. width × thickness × height: 20 mm × 50 mm × 100
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· Simulation of tunnel failure induced by structural plane is used by FDEM approach. Rock heterogeneity and excavation unloading process was fully considered. Dip angle, location, frictional coefficient and lateral coefficient were studied. The crack propagation and failure intensity is related to selected parameters.
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· In view of a previous study of the intermediate principal stress effect at a limited σ2 range, a series of true triaxial tests, covering a full range of intermediate principal stresses that vary from the generalized triaxial compression stress state (σ2 = σ3) to the generalized triaxial tensile stress state (σ1 = σ2), was carried out on sandstone and
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Rock failure is a combination of the results of elastic strain accumulation and dissipation by stress propagation. The key to inducing the energy storage capacity of rock before failure is closely related to the rock damage evolution. The pattern of energy release and dissipation through stress during rock failure was revealed from the
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· 1. Introduction. Under high-stress conditions, the excavation of hard rock. tunnels will cause rapid adjustment of secondary stress field. of the surrounding rock, which may lead to damage de
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