NIE C X, RAO J Y, LIU J H, et al.Study on the crystal composition and mechanism of tunnel drainage system[J].Journal of Henan Polytechnic University(Natural Science) ,2022,41(6):196-202.

doi:10.16186/j.cnki.1673-9787.2020110019

Received:2020/11/05

Revised:2022/03/10

Published:2022/11/25

Study on the crystal composition and mechanism of tunnel drainage system

NIE Chongxin1, RAO Junying1, LIU Jianhao1, LI Yuan1, WANG Shiguang2, XIE Caijin1

1.School of Civil Engineering，Guizhou University，Guiyang  550025，Guizhou，China；2.Second Engineering Co.，Ltd.,China Railway 18th Bureau Group ，Tangshan  063000，Hebei，China

Abstract:In oder to find effective crystallization disposition plan of the tunnel drainage system，taking the drainage system crystal material from Baiyanjiao Tunnel as the sample，the crystal phase was analyzed by X-ray diffraction（XRD），then the microstructure of the sample was observed by scanning electron microscope（SEM），and the pH and water temperature at the sampling site were measured in situ.The crystal material composition and crystal formation mechanism of the tunnel drainage system were analyzed and studied.It was found that in the drainage system of The Baiyanjiao tunnel，the crystals were divided into calcite（CaCO₃），brucite （Mg（OH）₂）and dolomite（CaMg（CO₃）₂）.According to the crystal form，it could be divided into adherent growth calcite crystal and conveyance deposition calcite crystal.The mechanism of crystallization chemical reaction was the mechanism of dolomization crystallization.The material basis of crystallization was provided by the lining concrete and the soluble rock together.The pH of the drainage place where the crystallization occured was between 9.1 and 12.3.

Key words:precipitation;tunnel drainage system;precipitation mechanism;crystallization dynamics;crystal phase

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