Investigation on the evolution characteristics and transfer mechanism of surrounding rock pressure for a hard-rock tunnel under high geo-stress: case study on the Erlang Mountain Tunnel, China

2021 ◽  
Author(s):  
Zihan Zhou ◽  
Ziquan Chen ◽  
Chuan He ◽  
Hao Kou
Keyword(s):  
Rock Pressure ◽  
Hard Rock ◽  
Surrounding Rock ◽  
Transfer Mechanism ◽  
Evolution Characteristics ◽  
Surrounding Rock Pressure ◽  
Rock Tunnel ◽  
Mountain Tunnel

scholarly journals Monitoring and support optimization analysis of surrounding rock pressure and initial supporting stress in deep-buried soft rock tunnel

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Q. Liu ◽  
R. Li ◽  
W. Tian ◽  
Y. Wang ◽  
X. Li
Keyword(s):  
Rock Pressure ◽  
Soft Rock ◽  
Northwest China ◽  
Surrounding Rock ◽  
Steel Frame ◽  
Control Effect ◽  
Measuring Point ◽  
Deformation Control ◽  
Surrounding Rock Pressure ◽  
Rock Tunnel

Attempting at the problems of surrounding rock pressure and initial supporting stress of deep-buried soft rock tunnel, a soft rock highway tunnel project in Northwest China was monitored on-site for surrounding rock deformation, surrounding rock pressure, initial stress and other items.Discuss the deformation laws and stress characteristics of surrounding rock and steel arch at different construction stages, and compare and analyze the deformation control effect of surrounding rock with different initial lining thickness, different initial elastic modulus and different anchor length through numerical simulation.The results show that the excavation stage of the upper step is a stage where the pressure and deformation of the surrounding rock increase rapidly. The steel arch support is mainly compressed, and the average stress can reach more than 50% of the peak value within 5 days. The stress is mostly higher than the measuring point of the lower step. The initial steel frame support of the upper step and the middle step bears a greater load. The excavation of the upper middle step should be "passed quickly and supported in time", and the construction should adopt The “letting first,then resisting” method appropriately increases the reserved deformation of the surrounding rock to relieve the support stress of the primary steel frame. When the deformation of the surrounding rock and the growth rate of the surrounding rock pressure slow down, the secondary lining can be applied in advance. The research results can provide reference and reference for the design and construction of similar tunnel projects.

Study on the Prediction Method of Tunnel Surrounding Rock Pressure Based on the Theory of Progressive Destruction

2012 ◽  
Vol 446-449 ◽  
pp. 1432-1436
Author(s):  
Suo Wang
Keyword(s):  
Rock Pressure ◽  
Characteristic Curve ◽  
Prediction Method ◽  
Surrounding Rock ◽  
Progressive Damage ◽  
Tunnel Excavation ◽  
Practical Engineering ◽  
Surrounding Rock Pressure ◽  
The Relationship ◽  
Rock Parameters

In order to predict tunnel surrounding rock pressure, this paper puts forward a series of dynamic numerical simulative model on the tunnel excavation. According to the change of rock damage in the construction program, it adjusts dynamically the mechanical material parameters of surrounding rock. So the model achieves the purpose which is controlling and simulating the process of tunnel progressive damage. In accordance with the numerical simulative results, it analyzes the relationship between the rock parameters with the plastic strain, radial displacement. Then this paper proposes a prediction method of tunnel surrounding rock pressure based on the theory of the progressive damage and method of characteristic curve. Finally, it compares the pressure on the numerical simulative models with on the site date, and it proves that the prediction method has practical engineering value.

FBG Earth Pressure Sensors Applied in Surrounding Rock Pressure of Tunnel

2013 ◽  
Vol 351-352 ◽  
pp. 1173-1178
Author(s):  
Zhou Chun Cai ◽  
Chuan Li ◽  
Yuan Yu Guan ◽  
Wu Fen Chen ◽  
Li Jun Guo ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Rock Pressure ◽  
Pressure Sensors ◽  
Earth Pressure ◽  
Surrounding Rock ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Stress Changes ◽  
Surrounding Rock Pressure

During the period of tunnel excavation, shoring, forming and long-term operation, stress changes of tunnel surrounding rock are complex, the real-time monitoring of surrounding rock pressure is the key factor in ensuring long-term stability in tunnel. Fiber Bragg grating earth pressure sensors apply in surrounding rock pressure of tunnel which can change the pressure of the surrounding rock into fiber Bragg grating wavelength shift. According to the feature of pressure and temperature in Tian Xin Tunnel, 40 earth pressure sensors are embedded in 20 representative sections and one earth pressure sensor is embedded in each arch shoulder. In addition, one temperature compensation sensor is embedded in each arch crown. During the 235 monitoring days, the biggest daily change of surrounding rock pressure reaches 800 KPa. In 3 months of the sensor installation, the average monthly variation is within 50 KPa. The long-term measurement results indicate that the changes of surrounding rock pressure are different in different locations. When the surrounding rock is close to the excavated and blasted surface the surrounding rock pressure changes largely.

Surrounding rock pressure of shallow-buried bilateral bias tunnels under earthquake

2015 ◽  
Vol 9 (4) ◽  
pp. 427-445 ◽  
Author(s):  
Xin-Rong Liu ◽  
Dong-Liang Li ◽  
Jun-Bao Wang ◽  
Zhen Wang
Keyword(s):  
Rock Pressure ◽  
Surrounding Rock ◽  
Surrounding Rock Pressure

scholarly journals Calculation of Surrounding Rock Pressure of Undercut Subway Station Based on Multi-Factor Affecting Pressure Arch Theory

Engineering ◽  
2020 ◽  
Vol 12 (02) ◽  
pp. 59-70
Author(s):  
Bin Shang ◽  
Xiaoguang Jin ◽  
Guiyong Ao ◽  
Qiao Chen ◽  
Qiong Qiu
Keyword(s):  
Rock Pressure ◽  
Surrounding Rock ◽  
Subway Station ◽  
Surrounding Rock Pressure

Study on a Surrounding Rock Pressure Calculation Method for Super-Large Section Highway Tunnels

Symmetry ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1133 ◽  
Author(s):  
Gao ◽  
He ◽  
Chen ◽  
Li
Keyword(s):  
Rock Pressure ◽  
Calculation Method ◽  
Surrounding Rock ◽  
Underground Structures ◽  
Large Section ◽  
Main Challenge ◽  
The World ◽  
Lining Structure ◽  
Surrounding Rock Pressure ◽  
Universal Applicability

This paper presents new correlations for estimating the surrounding rock pressure of symmetrically shaped tunnels based on a symmetrical numerical model. Surrounding rock pressure is defined as the load acting on the support structure due to the deformation of the surrounding rock after tunnel excavation. Surrounding rock pressure is directly related to the selection of the lining structure and the determination of support parameters. The main challenge in designing and proceeding with the construction process is choosing a calculation method for the surrounding rock pressure for super-large sections, and this has been the focus of research among the tunnel research community. The excavation area of Liantang tunnel of Shenzhen Eastern Transit Expressway (China) is over 400 m2, making it the largest highway tunnel in the world so far. Based on this project, this paper analyses the applicability of various traditional methods of calculating the surrounding rock pressure for super-large section tunnels. In addition, based on the Tunneling Quality Index (Q), the factor of span is introduced into the method of calculating the surrounding rock pressure using the numerical simulation results of super-large symmetrical tunnels with different values of Q and different spans. Additionally, calculated correlations that could quickly estimate the surrounding rock pressure of tunnels are obtained. The comparison of surrounding rock pressures between the estimated and monitoring results of Liantang tunnel and more than 30 projects around the world effectively proves the rationality and universal applicability of the proposed correlations. This method could provide engineers and designers with a quick way to predict the surrounding rock pressure of deep super-large section underground structures during their design and construction stage.

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