3D Numerical Analysis for Rock Support Design of an Underground Powerhouse Cavern in Complex Geological Conditions

2021 ◽  
Vol 833 (1) ◽  
pp. 012091
Author(s):  
E Yildiz ◽  
K Thermann ◽  
I Kamuf
Keyword(s):  
Numerical Analysis ◽  
Rock Support ◽  
Support Design ◽  
Underground Powerhouse ◽  
Geological Conditions

Numerical Analysis on Top Coal Caving of 2# Coal Seam in First Mine of Chagannaoer

2012 ◽  
Vol 594-597 ◽  
pp. 1338-1342
Author(s):  
Qing Hai Li ◽  
Ren Shu Yang ◽  
Wei Ping Shi
Keyword(s):  
Numerical Analysis ◽  
Plastic Zone ◽  
Coal Seam ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Mining Technology ◽  
Geological Conditions ◽  
Numerical Software ◽  
Evolution Laws ◽  
Overlying Strata

In first mine of Chagannaoer, 2# coal seam, the mainly mined out layer, was 22.00m thickness in average. In order to meet the requirements of production ability, the mine was planned to apply mining technology of fully mechanized caving. Good or bad of top coal’s caving was an important prerequisite which decided the mining technology of top coal caving could be chosen or not. Due to lack of producing mines in this region and no experience to refer, we simulated the mining process of 2# coal seam using numerical software of FLAC3D, and gained evolution laws of stress and displacement of top coal and overlying strata and expansion laws of plastic zone. Through analysis, we got that the top coal damaged seriously and the top coal could be caved smoothly. Relying on the geological conditions of site, we verified the simulated results with method of fuzzy comprehensive evaluation. Combined with the research results, we decided that 2# coal seam’s caving was better and was convenient for top coal caving, so it was suitable for caving mining in 2# coal seam in first mine of Chagannaoer.

scholarly journals Finite Element Analysis of Artificially Frozen C-Phi soil

2019 ◽  
Vol 8 (4) ◽  
pp. 12722-12728
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Frozen Soil ◽  
Experimental Results ◽  
Soil Freezing ◽  
Strength Parameter ◽  
Frozen Ground ◽  
Element Analysis ◽  
Test Setup ◽  
Geological Conditions

Artificial Ground Freezing techniques eliminate the need for structural supports during the course of an excavation, as frozen ground is solid and waterproof. At present, it is adopted as an effective way to deal with various construction ground control challenges such as the mitigation of seepage infiltration into tunnels and shaft excavations; or ground strengthening for excavation. In-depth knowledge of the frozen soil characteristics through experiments and the development of suitable constitutive models that suit the geological conditions of our country are necessary to predict the strength and behavior of the frozen soils. Numerical analysis of frozen soil can be used for mass works like tunneling which cannot be experimentally verified. This paper presents a validation of experimental results obtained from laboratory setup and soil freezing system for C-Phi soil. The main aim is to compare numerical and experimental results and hence obtaining the shear strength parameter of the soil, similar to the conventional triaxial test setup. To perform numerical analysis Finite element tool ANSYS 19 is used. Soil model is made in ANSYS 19 and required loads are inputted to performed the analysis similar to the experimental method. The result obtained from experimental test setup and numerical analysis was verified and compared and it was found that values of numerical results lies closer to experimental results

scholarly journals Key Factors Affecting the Deformation and Failure of Surrounding Rock Masses in Large-Scale Underground Powerhouses

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Meng Wang ◽  
Jia-wen Zhou ◽  
An-chi Shi ◽  
Jin-qi Han ◽  
Hai-bo Li
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Surrounding Rock ◽  
Rock Masses ◽  
Affecting Factors ◽  
Key Factors ◽  
Underground Powerhouse ◽  
Deformation And Failure ◽  
Factors Affecting ◽  
Geological Conditions

The stability of the surrounding rock masses of underground powerhouses is always emphasized during the construction period. With the general trends toward large-scale, complex geological conditions and the rapid construction progress of underground powerhouses, deformation and failure issues of the surrounding rock mass can emerge, putting the safety of construction and operation in jeopardy and causing enormous economic loss. To solve these problems, an understanding of the origins and key affecting factors is required. Based on domestic large-scale underground powerhouse cases in the past two decades, key factors affecting the deformation and failure of the surrounding rock mass are summarized in this paper. Among these factors, the two most fundamental factors are the rock mass properties and in situ stress, which impart tremendous impacts on surrounding rock mass stability in a number of cases. Excavation is a prerequisite of surrounding rock mass failure and support that is classified as part of the construction process and plays a pivotal role in preventing and arresting deformation and failure. Additionally, the layout and structure of the powerhouse are consequential. The interrelation and interaction of these factors are discussed at the end of this paper. The results can hopefully advance the understanding of the deformation and failure of surrounding rock masses and provide a reference for design and construction with respect to hydroelectric underground powerhouses.

scholarly journals Support System for Tunnelling in Squeezing Ground of Qingling-Daba Mountainous Area: A Case Study from Soft Rock Tunnels

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Xiuling Wang ◽  
Jinxing Lai ◽  
Rodney Sheldon Garnes ◽  
Yanbin Luo
Keyword(s):  
Support System ◽  
Strong Support ◽  
Mountainous Area ◽  
Squeezing Ground ◽  
Tunnel Face ◽  
Support Design ◽  
Tunnel Support ◽  
Geological Conditions ◽  
Rock Tunnels

Tunnelling or undertaking below-ground construction in squeezing ground can always present many engineering surprises, in which this complicated geology bring a series of tunnelling difficulties. Obviously, if the major affecting factors and mechanism of the structure damage in these complicated geological conditions are determined accurately, fewer problems will be faced during the tunnel excavation. For this study, reference is made to four tunnel cases located in the Qingling-Daba mountainous squeezing area that are dominated by a strong tectonic uplift and diversified geological structures. This paper establishes a strong support system suitable for a squeezing tunnel for the purpose of addressing problems exhibited in the extreme deformation of rock mass, structure crack, or even failure during excavation phase. This support system contains a number of temporary support measures used for ensuring the stability of tunnel face during tunnelling. The final support system was constructed, including some key techniques such as the employment of the foot reinforcement bolt (FRB), an overall strong support measure, and more reserved deformation. Results in this case study showed significant effectiveness of the support systems along with a safe and efficient construction process. The tunnel support system proposed in this paper can be helpful to support design and provide sufficient support and arrangement before tunnel construction in squeezing ground.

scholarly journals Numerical Analysis of Soil Improvement for a Foundation of a Factory Using Stone Columns Made of Different Types of Coarse-grained Materials

2019 ◽  
Author(s):  
Jakub Stacho ◽  
Monika Sulovska
Keyword(s):  
Numerical Analysis ◽  
Accurate Determination ◽  
Soil Improvement ◽  
Coarse Grained ◽  
Stone Columns ◽  
Modified Method ◽  
Geological Conditions ◽  
Deformation Properties ◽  
Final Settlement ◽  
The Impact

Stone columns made of coarse-grained materials and crushed stone are one of the most-used technologies for soil improvement all over the world. Stone columns improve the strength and deformation properties of subsoil and reduce the time required for the consolidation of fine-grained soils. The impact of the improvement depends on the properties of the original subsoil as well as the properties of the coarse-grained materials used for the stone columns. The article deals with the effects of the properties of coarse-grained materials for stone columns on the settlement and consolidation times of improved subsoil for the foundation of a factory. Numerical modeling as a 2D task was performed using Plaxis geotechnical software. The numerical analysis included two methods of modeling stone columns in a plane strain model, i.e., one method often used by practical engineers in the region of Slovakia, and one modified method, which allowed for a more accurate determination of the final settlement and consolidation time. The method modeled stone columns as continuous walls, and the compaction of the soil between the stone columns was taken into account. The results showed that the type of coarse-grained material can significantly affect the final settlement and time of consolidation. Stone columns made of quarry stone were suitable in the given geological conditions regardless of the design of the mesh, while stone columns made of pebble gravel were suitable only with a mesh of 1.5 x 1.5 m.

Numerical Analysis for a Realistic Support Design: Case Study of the Komurhan Tunnel in Eastern Turkey

2016 ◽  
Vol 16 (3) ◽  
pp. 05015001 ◽  
Author(s):  
Erkut Yalcin ◽  
Zulfu Gurocak ◽  
Rouzbeh Ghabchi ◽  
Musharraf Zaman
Keyword(s):  
Numerical Analysis ◽  
Support Design ◽  
Eastern Turkey ◽  
Design Case ◽  
Design Case Study

Numerical Analysis of Lining Temperature Field of Hydraulic Tunnel under the Highway

2010 ◽  
Vol 163-167 ◽  
pp. 1505-1509
Author(s):  
Xiao Yun Jia ◽  
Bao Long Lin
Keyword(s):  
Temperature Field ◽  
Numerical Analysis ◽  
Structural Characteristics ◽  
Crack Control ◽  
Temperature Changes ◽  
Finite Element Software ◽  
Concrete Crack ◽  
Geological Conditions ◽  
North Water ◽  
The Difference

Based on the geological conditions of culvert of the South to North Water Transfer Project, lining temperature field of hydraulic tunnel for crack control is simulated by finite element software—ANSYS. According to numerical analysis results of lining temperature field, considering terrain condition, structural characteristics and climate, some engineering measures are taken during construction. Internal temperature of concrete is controlled effectively, concrete crack caused by temperature changes is solved successfully, and construction quality is assured. The difference of measuring data in-situ and calculating data is very small, which illustrate that calculated model is correct and parameters are reasonable. The results can act as reference for the design and construction of similar projects later.

Stability of development drifts in difficult geological conditions of Starobin deposit

2020 ◽  
pp. 26-32
Author(s):  
B. I. Petrovsky ◽  
◽  
V. A. Misnikov ◽  
K. A. Erokhin ◽  
A. B. Petrovsky ◽  
...  
Keyword(s):  
Potassium Salt ◽  
Deep Level ◽  
Maximum Efficiency ◽  
Salt Deposit ◽  
Support Design ◽  
Underground Openings ◽  
Geological Conditions ◽  
Stability Of Development ◽  
Yielding Support ◽  
Roof Rocks

Extraction of the remaining reserves at the Starobinsk potassium salt deposit is associated with degradation of geological conditions as the content of clay beds in roof rocks increases with depth. The article presents the underground test data on the most promising techniques of roof support in development entries in deep-level unstable rocks in the Starobinsk potassium salt deposit. In an operating mine, various combinations of different support types and ground control approaches were tested, namely, compensation voids (slotting, racking) and long roof bolting. It is found that the maximum efficiency of development heading support is achieved with the combination of destressing headings and compensation slots. These flow charts are applicable to a depth of 860–900 m at the clay bed content of 35%. At the depths greater than 900 m and at the clay bed content higher than 35%, each underground excavation should have a specific support type. In extremely complex conditions at any depth and at the clay bed content from 35 to 60% in the roof, the support design for long underground openings with a span to 3.8 m, without slots in the sidewalls can involve roof scaling up to the roof arch (pressure arch) and installation of special-shape and expansion-type yielding support in sidewalls.

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