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Structural Non-destructive Evaluation of Cleaning Solvent for Clogging Removing of Karst Tunnel Drainage System
(1 Nanchang Railway Survey and Design Institute Co., Ltd., Nanchang 330002;2 Communications Design & Research Institute Co. Ltd of Jiangxi Province, Nanchang 330200)
Abstract Drainage system blocked by Karst crystal is often encountered in tunnelling in Karst area, threatening
structure safety and long-term operation of tunnels. A unimolecule carboxylic organic acid agent with optimal concentration of 2 000 ppm and dichromate index of 17.71% is identified as a cleaning solvent based on a study of preparation and efficiency of cleaning solvent for removing of drainage clogging in karst tunnel, and a non-destructive evaluation of selected cleaning solvents on tunnel lining concrete and PVC plastic fiber materials of drainage system is conducted. Firstly, a test of organic acid solvent soaked concrete specimens is carried out to evaluate the strength damage of concrete due to erosion by solvent. Secondly, an experiment of soaking PVC drainage board and plastic blind ditch tube with organic acid reagent solution is carried out to evaluate the effect of solvent on quality loss and corrosion damage of tunnel drainage system from the macroscopic and microscopic perspectives. The results indicate that strength index of concrete material is reduced by about 7%-9% due to erosion of unimolecule carboxylic
organic acid reagent, while it barely has any corrosion damage on the plastic material of drainage system.
Abstract：
Drainage system blocked by Karst crystal is often encountered in tunnelling in Karst area, threatening
structure safety and long-term operation of tunnels. A unimolecule carboxylic organic acid agent with optimal concentration of 2 000 ppm and dichromate index of 17.71% is identified as a cleaning solvent based on a study of preparation and efficiency of cleaning solvent for removing of drainage clogging in karst tunnel, and a non-destructive evaluation of selected cleaning solvents on tunnel lining concrete and PVC plastic fiber materials of drainage system is conducted. Firstly, a test of organic acid solvent soaked concrete specimens is carried out to evaluate the strength damage of concrete due to erosion by solvent. Secondly, an experiment of soaking PVC drainage board and plastic blind ditch tube with organic acid reagent solution is carried out to evaluate the effect of solvent on quality loss and corrosion damage of tunnel drainage system from the macroscopic and microscopic perspectives. The results indicate that strength index of concrete material is reduced by about 7%-9% due to erosion of unimolecule carboxylic
organic acid reagent, while it barely has any corrosion damage on the plastic material of drainage system.
HONG Yingwei1,
2
.Structural Non-destructive Evaluation of Cleaning Solvent for Clogging Removing of Karst Tunnel Drainage System[J] MODERN TUNNELLING TECHNOLOGY, 2020,V57(4): 219-
2020, Vol. 57 