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Experimental Study and Numerical Simulation of Crystallization-induced Blockage in Drainage Pipes in Karst Tunnels
1. CCCC Road and Bridge Construction Co., Ltd., Beijing 101100; 2. School of Earth Sciences and Engineering, Hohai University,Nanjing 211100; 3. Nanjing Aqua-World Institute of Seawater Desalination, Nanjing 210046; 4. School of Earth Sciences and Engineering, Nanjing University, Nanjing 210046)
Abstract In order to realize the accurate description, early warning and control of the blockage process of the tun? nel drainage system in the karst area, the laboratory test on blockage in the drainage pipe system is carried out at the 1∶1 scale, and the variation law of the crystal precipitation is discussed under the conditions of field hydrodynamics,hydrochemistry and wetting-drying cycle. The numerical model of crystallization-induced blockage in tunnel drainage pipes in karst areas is constructed considering the coupled driving process of hydrodynamic force and dissolution-precipitation reaction of carbonate components, and is verified combined with the laboratory test data. The simulation results show that the error between the simulated values and the experimental observation values is gradually decreased as time goes by, and the determination coefficient of fitting (R2) reaches 0.67 at about 15 d, proving that the numerical model can predict the crystallization process in the tunnel drainage pipes in a relatively long time scale. The proposed model can provide theoretical guidance for the prevention and control of blockage in the tunneldrainage system, and further guarantee the early identification and safety assessment of geological hazards of karst tunnels.
Abstract：
In order to realize the accurate description, early warning and control of the blockage process of the tun? nel drainage system in the karst area, the laboratory test on blockage in the drainage pipe system is carried out at the 1∶1 scale, and the variation law of the crystal precipitation is discussed under the conditions of field hydrodynamics,hydrochemistry and wetting-drying cycle. The numerical model of crystallization-induced blockage in tunnel drainage pipes in karst areas is constructed considering the coupled driving process of hydrodynamic force and dissolution-precipitation reaction of carbonate components, and is verified combined with the laboratory test data. The simulation results show that the error between the simulated values and the experimental observation values is gradually decreased as time goes by, and the determination coefficient of fitting (R2) reaches 0.67 at about 15 d, proving that the numerical model can predict the crystallization process in the tunnel drainage pipes in a relatively long time scale. The proposed model can provide theoretical guidance for the prevention and control of blockage in the tunneldrainage system, and further guarantee the early identification and safety assessment of geological hazards of karst tunnels.
CHENG Yongchun1 ZENG Xiangji1 WANG Zhenjia1 WANG Dong1 YANG Yun2 WU Yongjing3 DONG Ping3,
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.Experimental Study and Numerical Simulation of Crystallization-induced Blockage in Drainage Pipes in Karst Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(2): 159-166
2022, Vol. 59 