scholarly journals Failure Mechanism and Numerical Simulation of Splitting Failure for Deep High Sidewall Cavern Under High Stress

2021 ◽  
Author(s):  
Fan Li ◽  
Qiangyong Zhang ◽  
Wen Xiang ◽  
Guangyuan Yu
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Strain Gradient ◽  
High Stress ◽  
Three Dimensional ◽  
Strain Gradient Theory ◽  
Geomechanical Model ◽  
Geomechanical Model Test ◽  
3D Geomechanical Model ◽  
Splitting Failure

Abstract With the increase of the depth of the underground engineering, the phenomenon of splitting failure of the deep rock will appear, which is very different from the shallow cavern. In order to reveal the formation mechanism of splitting damage, mechanical model tests and numerical simulations of splitting damage were carried out respectively. Using the Pubugou Hydropower Station as the engineering background, a three-dimensional (3D) geomechanical model test was conducted relying on a high stress three-dimensional load test system. The splitting damage phenomenon of high sidewall cavern was observed, and the oscillation variations of displacement and stress were measured. Based on strain gradient theory and continuum damage mechanics, an elastic-plastic damage softening model for splitting damage was established. The relationship between rock damage and energy dissipation was analyzed. Based on the strain energy density theory, the splitting damage criterion based on the strain gradient is established. A numerical analysis method for splitting damage was proposed, and a regional disintegration calculation program was developed based on a commercial finite element code. The numerical simulation results are in basic agreement with the 3D geomechanical model test.

Study on Predictin of Surface Subsidence of an Exremely Shallow Large-Span Double-Arch Tunnel

2011 ◽  
Vol 396-398 ◽  
pp. 2245-2248
Author(s):  
Xin Zhi Li ◽  
Shu Cai Li ◽  
Shu Chen Li ◽  
Xian Da Feng ◽  
Chao Yuan ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Surface Subsidence ◽  
Tunnel Construction ◽  
Geomechanical Model ◽  
Large Span ◽  
Geomechanical Model Test ◽  
Construction Methods ◽  
Surface Subsidence Control ◽  
Great Wall

The Qi-Great Wall tunnel which crossed the Qi -Great Wall ruins was a large span double-arch tunnel with two-way and six-lane and the maximum depth was less than 5 meters, in order to protect the safety of thr surface ruins in the tunnel construction progress, surface subsidence control was particularly important. Through comprehensive geomechanical model test and numerical simulation , the surface subsidence wich generated in the process of construction according to construction methods of excavation and support was studied, the distribution of surface subsidence got through two methods was fitted well,and research results could provide guidance for the construction.

Analysis of Stability and Reinforcement of Faults of Baihetan Arch Dam

2011 ◽  
Vol 243-249 ◽  
pp. 4506-4510 ◽  
Author(s):  
Fu Hai Guan ◽  
Yao Ru Liu ◽  
Qiang Yang ◽  
Ruo Qiong Yang
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Stable State ◽  
Arch Dam ◽  
Geomechanical Model ◽  
Measuring Point ◽  
Geomechanical Model Test ◽  
Unbalanced Force ◽  
Damage Law ◽  
Analysis Of Stability

With the deformation reinforcement theory (DRT), numerical simulation of Baihetan arch dam and foundation is carried out. According to the unbalanced forces distribution, fault F18and shear zone LS3318are the key reinforcement regions and unbalanced force of each fault is the corresponding optimal reinforcement force which is to maintain a stable state. To verify the validity of the results of numerical simulation, geomechanical model test of Baihetan arch dam is carried out. By analyzing displacement of corresponding measuring point in the overloading process, and observing failure of transverse section at each elevation, the results show that the unbalanced force distribution of each fault is consistent with the damage law of faults in geomechanical model test.

scholarly journals Experimental Study on the Ratio of Similar Materials in Weak Surrounding Rock Based on Orthogonal Design

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Pengfei Jiao ◽  
Xiao Zhang ◽  
Xinzhi Li ◽  
Bohong Liu ◽  
Haojie Zhang
Keyword(s):  
Model Test ◽  
Orthogonal Design ◽  
Surrounding Rock ◽  
Similar Material ◽  
Geomechanical Model ◽  
Geomechanical Model Test ◽  
Geological Conditions ◽  
Key Factor ◽  
Similar Materials ◽  
Weak Surrounding Rock

In the aspect of stability analysis of tunneling engineering, geomechanical model test is an important research method. A similar material is the prerequisite for the success of geomechanical model test. In the field of major engineering applications, a variety of similar materials are prepared for different geological conditions of surrounding rock and applied in some major engineering. With the use of standard sand, fine sand, and silt clay as materials, similar materials for weak surrounding rock were developed. Based on the orthogonal design method, through the direct shear test, the range analysis and variance analysis of various factors affecting the physical and mechanical parameters of weak surrounding rock are carried out. The results show similar material can meet the requirements in weak surrounding rock. Standard sand is the key factor that influences the internal friction angle of similar materials, and silt clay is the key factor affecting the cohesion of similar materials. Similar materials can meet the elastic modulus and severe requirements of the weak surrounding rock and can be used for the weak surrounding rock engineering. The new type of similar material configuration is widely used in shallow buried tunnel entrance section and urban shallow buried excavation engineering, in addition to tunnel engineering in loess stratum, and the problems of engineering design and construction are solved through geomechanical model test.

Bimaterial Interfacial Crack Growth With Strain Gradient Theory

1999 ◽  
Vol 121 (4) ◽  
pp. 413-421 ◽  
Author(s):  
Su Hao ◽  
Wing Kam Liu
Keyword(s):  
Crack Growth ◽  
Strain Gradient ◽  
High Stress ◽  
Stress Triaxiality ◽  
Interfacial Crack ◽  
Strain Gradient Theory ◽  
Gradient Theory ◽  
Theory Analysis ◽  
Theoretical And Numerical Analysis ◽  
Material Mismatch

The purpose of this paper is to investigate the effect of material heterogeneity on damage evolution and subsequent crack propagation in bimaterial systems. Strain gradient theory analysis reveals that a higher stress triaxiality always occurs on the softer material side due to the material mismatch in yield capacity and the corresponding strain gradient along the interface. High stress triaxiality is a major condition which promotes ductile damage and facilitates crack growth. To investigate this link, numerical simulations of ductile interface crack growth are performed using a damage based constitutive model. Both the numerical and experimental results show that a crack may grow along the interface or deviate into the softer material, but never turn into the harder material. The theoretical and numerical analysis reveal three factors which strongly affect the direction of crack growth and the resistance capacity of the bimaterial system against fracture. These are the boundary conditions which determine the global kinematically admissible displacement field, the stress/strain gradient near the interface due to the material mismatch, and the distance from the crack tip to the interface.

scholarly journals Construction of a 3d geomechanical model and its influence on the dynamic indicators of a carbonate reservoir model

2021 ◽  
Vol 3 (1) ◽  
pp. 43-55
Author(s):  
D. B. Abishev ◽  
V. V. Shishkin ◽  
I. G. Alekhin ◽  
A. Z. Nasibullin
Keyword(s):  
Hydrodynamic Model ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Carbonate Reservoir ◽  
Oil Field ◽  
Gas Content ◽  
Property A ◽  
Geomechanical Model ◽  
History Match ◽  
3D Geomechanical Model

The article presents the process and results of constructing a three-dimensional geomechanical model of an oil field located in the eastern edge of the Caspian basin. Oil and gas content is established in carbonate deposits of the Lower and Middle Carboniferous. The model was based on well log data, one-dimensional geomechanical models and a 3D geological model. The result of geomechanical modeling is the obtained property of additional permeability of the critically loaded discrete fracture network, which was later used in the history match of the hydrodynamic model. In addition to the fracture property, a series of conductive faults were also identified during the history match. When carrying out geomechanical modeling, international experience was taken into account in the calculation of critically loaded fractures and their relationship with the intervals of inflow and loss in carbonate reservoirs. The updated hydrodynamic model, taking into account the geomechanical model, significantly improved the convergence of the model and historical indicators of bottomhole pressures.

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