Experimental investigation on splitting failure of high sidewall cavern under three-dimensional high in-situ stress

Large scale underground caverns are under construction in high in-situ stress field at Houziyan hydropower station. To investigate deformation and damage of surrounding rock mass, a elastoplastic orthotropic damage model capable of describing induced orthotropic damage and post-peak behavior of hard rock is used, together with a effective approach accounting for the presence of weak planes. Then a displacement based back analysis was conducted by using the measured deformation data from extensometers. The computed displacements are in good agreement with the measured ones at most of measurement points, which confirm the validities of constitutive model and numerical simulation model. The result of simulation shows that damage of surrounding rock mass is mainly dominated by the high in-situ stress rather than the weak planes and heavy damage occur at the cavern shoulders and side walls.

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Damage Adaptive Titanium Alloy by In-Situ Elastic Gradual Mechanism

Materials ◽

10.3390/ma13020406 ◽

2020 ◽

Vol 13 (2) ◽

pp. 406

Author(s):

Siqian Zhang ◽

Jing Liu ◽

Haoyu Zhang ◽

Jie Sun ◽

Lijia Chen

Keyword(s):

Titanium Alloy ◽

Damage Tolerance ◽

Three Dimensional ◽

Crack Tip ◽

In Situ Stress ◽

Crack Deflection ◽

Adaptive Mechanism ◽

Ultrafine Grained ◽

Elastic Gradient

Natural materials are generally damage adaptive through their multilevel architectures, with the characteristics of compositional and mechanical gradients. This study demonstrated that the desired elastic gradient can be in-situ stress-induced in a titanium alloy, and that the alloy showed extreme fatigue-damage tolerance through the crack deflection and branch due to the formation of a three-dimensional elastically graded zone surrounding the crack tip. This looks like a perceptive and adaptive mechanism to retard the crack: the higher stress concentrated at the tip and the larger elastic gradient to be induced. The retardation is so strong that a gradient nano-grained layer with a thickness of less than 2 μm formed at the crack tip due to the highly localized and accumulated plasticity. Furthermore, the ultrafine-grained alloy with the nano-sized precipitation also exhibited good damage tolerance.

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Field measurements of rock displacement in deep shafts in quartzite with high in situ stress

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(87)91575-0 ◽

1987 ◽

Vol 24 (1) ◽

pp. A40

Keyword(s):

Field Measurements ◽

In Situ Stress ◽

High In Situ Stress

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Research of Mining Method for Difficult-to-Mine Ore Bodies in Deep Mine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.962-965.1041 ◽

2014 ◽

Vol 962-965 ◽

pp. 1041-1046

Author(s):

Qi Fa Ge ◽

Xue Sen Sun ◽

Wei Gen Zhu ◽

Qing Gang Chen

Keyword(s):

In Situ Stress ◽

Mining Method ◽

Deep Mining ◽

Deep Mine ◽

Ore Body ◽

High In Situ Stress ◽

Ore Bodies ◽

Large Panel ◽

Back Filling

There are many problems such as depth, high in-situ stress, high ground temperature and rockburst proneness etc. in deep mining. And it is an acknowledged and urgent mining technical puzzle about mining method of gently inclined and medium-thick ore bodies. For such an ore body in West wing of Dongguashan copper mine, if we use traditional mining method, it is hard to conquer such difficulties as high in-situ stress, large open area in roof, removal of mined ore by gravity etc. The theory of “large panel and lower sublevel height” will be easy to solve such problems. This paper use numerical technology to analyze and compare the technical and economical effectiveness for different selected mining method and its structure. The sublevel (at a height of 12 m) open stoping with back-filling by extraction in two steps is quite suitable for ensuring safety, increasing efficiency, productivity and reclaiming resource. The selected method is feasible and well worth spread.

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