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 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.

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.

Analysis of Soil Disturbance by Shield Tunneling

2013 ◽  
Vol 734-737 ◽  
pp. 502-506
Author(s):  
Meng Lin Xu ◽  
De Shen Zhao
Keyword(s):  
Numerical Simulation ◽  
Soil Disturbance ◽  
Technical Support ◽  
Surface Subsidence ◽  
Stress Redistribution ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Soil Deformation ◽  
Shield Tunneling ◽  
Induced Stress

The shield tunneling will be bound to disturb surrounding strata, induced stress redistribution in soil, soil deformation and surface subsidence. We analyzed characteristics of soil disturbance by shield tunneling with numerical simulation. To provide technical support for the future urban shield tunnel construction. It shows practically significant in studying shield tunnel construction.

Numerical Simulation for Construction Process Large-Span Flat Tunnel under the Condition of Shallow Buried

2014 ◽  
Vol 580-583 ◽  
pp. 1100-1104
Author(s):  
Jun Jie Li ◽  
Li Tuo ◽  
Guan Jun Zhang
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Tunnel Construction ◽  
Construction Process ◽  
Large Span ◽  
Tunneling Method ◽  
Stress Changes ◽  
Flac 3D ◽  
3D Software ◽  
Grade Rock

The thesis takes a three-lane tunnel construction in Zhejiang as an example. Simulating the course of dynamic construction of large-span tunnel on geology condition of four-grade rock mass and shallow buried by FLAC 3D software ,it carries out comparative and stress situation in the runnel surrounding rocks .Getting the displacement and stress changes rule of the construction by using benching with a small pilot tunnel tunneling method can guide the construction scientifically.

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