Performance Assessment and Optimization of Seepage Control System for Wunonglong Underground Powerhouse Cavern System
Publication: International Journal of Geomechanics
Volume 24, Issue 9
Abstract
The problem of seepage control is faced in the construction of large underground powerhouse cavern systems. To reduce leakage and improve the permeability stability of the surrounding rock, a complex seepage control system, including drainage hole arrays, drainage tunnels, and grouting curtains, was designed for the Wunonglong underground powerhouse caverns. In this study, we performed a seepage field numerical analysis of the Wunonglong underground powerhouse caverns system to optimize the seepage control system. A three-dimensional numerical model was established considering the complex seepage control system and the geological conditions. A steady seepage analysis method, with a variational inequality formulation, was adopted in order to calculate the long-term seepage field. A drainage substructure method was used to simulate the seepage behavior of the densely arranged drainage hole arrays. The seepage control effects of single and double grouting curtains were compared to determine a reasonable curtain layout scheme. The effect of the drainage system on the seepage control of the powerhouse caverns is further discussed. The findings offer reliable insights into the seepage behavior of underground powerhouse caverns and provide a reference for the design and construction of similar underground powerhouse cavern systems.
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Data Availability Statement
All data, models, and code generated or used during the study appear in the published article.
Acknowledgments
This study was supported by the National Natural Science Foundation of China (Nos. 52039008, 52125904), the Scientific Research Program funded by Shaanxi Provincial Education Department (No. 23JP113), and the China Postdoctoral Science Foundation (Nos. 2021T140554, 2020M683527).
Notation
The following symbols are used in this paper:
- B
- geometrical matrix of the finite-element model;
- Hh,c
- calculated value of the hth observation point;
- Hk,g
- observed value of the hth observation point;
- penalized Heaviside function;
- H(φ − z)
- Heaviside function;
- h
- borehole number;
- K
- overall geometric permeability matrix;
- Kij
- the jth hydraulic conductivity of the ith area;
- k
- iterative step;
- ke
- element geometric permeability matrix;
- k1
- hydraulic conductivity;
- n
- total number of geological boreholes;
- nu
- outward unit normal vector to the boundary;
- p
- pore water pressure;
- q
- permeability rate;
- qn
- prescribed flux on Γq;
- v
- flow velocity;
- v0
- initial velocity;
- z
- elevation head;
- Γf
- seepage-free surface;
- Γq
- flow boundary;
- Γs
- potential seepage overflow boundary;
- Γφ
- water head boundary;
- γw
- density of water;
- gradient operator;
- finite-dimensional trial vector space;
- φ
- total water head;
- prescribed water head on boundary;
- ψ, φk, φk+1
- water head vector;
- Ω
- whole domain for seepage;
- Ωd
- dry zone;
- Ωe
- calculation domain;
- wet zone; and
- ωh
- weight function of the hth observation point.
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Information & Authors
Information
Published In
International Journal of Geomechanics
Volume 24 • Issue 9 • September 2024
Copyright
© 2024 American Society of Civil Engineers.
History
Received: Jul 26, 2023
Accepted: Feb 27, 2024
Published online: Jul 10, 2024
Published in print: Sep 1, 2024
Discussion open until: Dec 10, 2024
ASCE Technical Topics:
- Construction engineering
- Control systems
- Drainage
- Drainage systems
- Energy engineering
- Energy infrastructure
- Engineering fundamentals
- Geomechanics
- Geotechnical engineering
- Infrastructure
- Irrigation engineering
- Lifeline systems
- Models (by type)
- Numerical models
- Power plants
- Seepage
- Soil mechanics
- Soil properties
- Special condition construction
- Structural engineering
- Structures (by type)
- Systems engineering
- Systems management
- Underground construction
- Underground structures
- Water and water resources
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