scholarly journals Water Inrush Analysis of the Longmen Mountain Tunnel Based on a 3D Simulation of the Discrete Fracture Network

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Ziming Xiong ◽  
Mingyang Wang ◽  
ShaoShuai Shi ◽  
YuanPu Xia ◽  
Hao Lu ◽  
...  
Keyword(s):  
Water Inrush ◽  
Three Dimensional ◽  
Dynamics Simulation ◽  
Water Inflow ◽  
Tunnel Construction ◽  
Construction Technology ◽  
Mountain Area ◽  
Groundwater Dynamics ◽  
Discrete Fracture ◽  
Mountain Tunnel

AbstractThe construction of tunnels and underground engineering in China has developed rapidly in recent years in both the number and the length of tunnels. However, with the development of tunnel construction technology, risk assessment of the tunnels has become increasingly important. Water inrush is one of the most important causes of engineering accidents worldwide, resulting in considerable economic and environmental losses. Accordingly, water inrush prediction is important for ensuring the safety of tunnel construction. Therefore, in this study, we constructed a three-dimensional discrete network fracture model using the Monte Carlo method first with the basic data from the engineering geological map of the Longmen Mountain area, the location of the Longmen Mountain tunnel. Subsequently, we transformed the discrete fracture networks into a pipe network model. Next, the DEM of the study area was analysed and a submerged analysis was conducted to determine the water storage area. Finally, we attempted to predict the water inrush along the Longmen Mountain tunnel based on the Darcy flow equation. Based on the contrast of water inrush between the proposed approach, groundwater dynamics and precipitation infiltration method, we conclude the following: the water inflow determined using the groundwater dynamics simulation results are basically consistent with those in the D2K91+020 to D2K110+150 mileage. Specifically, in the D2K91+020 to D2K94+060, D2K96+440 to D2K98+100 and other sections of the tunnel, the simulated and measured results are in close agreement and show that this method is effective. In general, we can predict the water inflow in the area of the Longmen Mountain tunnel based on the existing fracture joint parameters and the hydrogeological data of the Longmen Mountain area, providing a water inrush simulation and guiding the tunnel excavation and construction stages.

scholarly journals Dynamic Change Characteristics of Groundwater Affected by Super-Long Tunnel Construction in the Western Mountainous Area of China

2019 ◽  
Vol 11 (8) ◽  
pp. 2329
Author(s):  
Zhiqiang Zhang ◽  
Peng Xu ◽  
Heng Zhang ◽  
Kangjian Zhang
Keyword(s):  
Fault Zone ◽  
Dynamic Change ◽  
Water Inrush ◽  
Water Inflow ◽  
Economic Losses ◽  
Tunnel Construction ◽  
In Situ Observation ◽  
Mountainous Area ◽  
Linear Cavity ◽  
Change Characteristics

The problem of groundwater is very prominent in super-long tunnel construction, which brings serious potential safety hazards and economic losses to the project. The knowledge of dynamic change characteristics of groundwater and prediction of water inflow is the key to ensure rational design and safe construction in super-long tunnel. In this paper, numerical simulation and in situ observation are conducted to investigate dynamic change characteristics of groundwater and the prediction of water inflow based on the Daxiangling tunnel in Sichuan Province of China. The results show that the numerical model established with detailed geological data and validated with field monitoring data can effectively analyze dynamic change characteristics of groundwater, as well as predict water inflow. The initial state of groundwater is steady when the tunnel is unexcavated. Tunnel excavation has a significant influence on the distribution of groundwater. The flow direction of groundwater will change, and the contour lines of groundwater will be intensive at the tunnel face. These changes will be more obvious and dramatic when the tunnel is excavated into the fault zone, which is a signal that the water inrush is more likely to occur in the fault zone because of a lot of joints and fractures. A connected linear cavity is formed with tunnel holing-through and groundwater begins to flow vertically downwards to the tunnel. As far as the prediction of water inflow is concerned, the numerical method can more precisely calculate the value of water inflow with less than 15 percent relative error compared with the groundwater dynamics method.

scholarly journals Analysis of Tunnel Water Inrush Considering the Influence of Surrounding Rock Permeability Coefficient by Excavation Disturbance and Ground Stress

2021 ◽  
Vol 11 (8) ◽  
pp. 3645
Author(s):  
Helin Fu ◽  
Pengtao An ◽  
Long Chen ◽  
Guowen Cheng ◽  
Jie Li ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Water Pressure ◽  
Water Inrush ◽  
Surrounding Rock ◽  
Water Inflow ◽  
Calculation Error ◽  
External Water Pressure ◽  
Ground Stress ◽  
External Water ◽  
Inflow Prediction

Affected by the coupling of excavation disturbance and ground stress, the heterogeneity of surrounding rock is very common. Presently, treating the permeability coefficient as a fixed value will reduce the prediction accuracy of the water inflow and the external water pressure of the structure, leading to distortion of the prediction results. Aiming at this problem, this paper calculates and analyzes tunnel water inflow when considering the heterogeneity of permeability coefficient of surrounding rock using a theoretical analysis method, and compares with field data, and verifies the rationality of the formula. The research shows that, when the influence of excavation disturbance and ground stress on the permeability coefficient of surrounding rock is ignored, the calculated value of the external water force of the tunnel structure is too small, and the durability and stability of the tunnel are reduced, which is detrimental to the safety of the structure. Considering the heterogeneity of surrounding rock, the calculation error of water inflow can be reduced from 27.3% to 13.2%, which improves the accuracy of water inflow prediction to a certain extent.

scholarly journals Application of temporary reinforcement technology in insufficient construction of the understructure bearing capacity of viaduct

2019 ◽  
Vol 136 ◽  
pp. 04080
Author(s):  
Guohui Cao ◽  
Reqiang Liu ◽  
Jing Liu ◽  
Xiang Gao ◽  
Peng Wang
Keyword(s):  
Bearing Capacity ◽  
Three Dimensional ◽  
Social Benefits ◽  
Construction Technology ◽  
Project Cost ◽  
Special Cases ◽  
Project Construction ◽  
Lower Structure ◽  
Traditional Construction

The complex three-dimensional traffic construction often occur when the lower structure cannot bear the construction load and other special cases, indicating the need for temporary reinforcement of the lower structure. In this paper, combined with a project construction example, various temporary reinforcement technologies are adopted to solve the insufficient bearing capacity during understructure construction, which poses a serious danger, to ensure synchronous construction of the understructure and viaduct. Compared with the traditional construction technology, the temporary reinforcement technology proposed in this paper features the advantages of saving project cost and time and has achieved better economic and social benefits.

scholarly journals Characterizing Reactive Transport Behavior in a Three-Dimensional Discrete Fracture Network

2021 ◽  
Author(s):  
Thomas Sherman ◽  
Guillem Sole-Mari ◽  
Jeffrey Hyman ◽  
Matthew R. Sweeney ◽  
Daniel Vassallo ◽  
...  
Keyword(s):  
Reactive Transport ◽  
Three Dimensional ◽  
Fracture Network ◽  
Discrete Fracture Network ◽  
Transport Behavior ◽  
Discrete Fracture
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