岩溶隧道排水系统堵塞机理的调查与分析

针对岩溶隧道中普遍出现的排水系统堵塞的问题,调研部分工程实例并探讨相关问题的发生机理和影响因素的作用。由岩溶发育和沉积机理可知,岩溶隧道排水系统的堵塞可分为化学结晶和碎屑沉积两方面的作用。从岩溶沉积的化学反应过程来看,岩溶动力系统是一个三相动态平衡体系,当其中的变量发生变化即可能会造成岩溶隧道排水设施结晶堵塞,主要影响因素包括CO2分压、流速、温度、pH值、离子种类和浓度。从工程影响因素来看,混凝土衬砌的溶出物、排水系统的设计和施工、隧道开挖造成地下水均衡状态都会造成岩溶隧道排水系统堵塞。

Investigation and Discussion on Blocking Mechanism of Drainage System in Karst Tunnels

The mechanism and influencing factors of the blocking of drainage system in karst tunnels are discussed based on case investigation and theory analysis. According to the mechanism of karst development and deposition, the blockage of the tunnel drainage system can be divided into two aspects: chemical crystallization and detrital deposition. From the chemical reactions of karst deposition process, karst dynamic system can be seen as a three-phase dynamic balance system, and the changing of main variables in this system including PCO_2, flow rate, temperature, pH, ionic species and concentration may cause the crystallization blockage of tunnel drainage facilities. From the perspective of engineering factors, the dissolving substances from concrete lining, the design and construction of drainage system, and the equalization of groundwater balance caused by tunnel excavation are all the factors, which may cause the blockage of drainage system in karst tunnels.