摘要
针对铁路隧道排水系统结晶堵塞问题,在银西铁路隧道对排水系统内外环境进行现场实测,开展结晶体X射线衍射、扫描电镜等测试及不同部位水样pH值与成分检验;模拟结晶体生成过程,分析结晶机理及影响因素,提出排水系统结晶应对措施。研究结果表明:铁路隧道排水系统结晶体主要成分为碳酸钙类矿物,以方解石和球霰石的形貌出现;初期支护喷射混凝土中的水泥及高碱性速凝剂是结晶物质主要来源,其中水泥水化过程中产生的Ca(OH)2等碱性物质溶解于地下水而流失,强碱性水体在排水系统高温高湿环境条件及CO2分压变化等的共同作用下,沉淀生成碳酸钙类矿物结晶体;增强排水系统的密封性、排水界面的光滑性与耐沾污性,提升初期支护喷射混凝土密实度等可以缓解铁路隧道排水系统结晶堵塞现象。
Aiming at the problem of the crystallization blockage in the drainage system of railway tunnel,field measurements of both the internal and external environments of the drainage system were conducted in Yinxi Railway tunnels.The crystal X-ray diffraction,scanning electron microscopy and other tests were carried out,and the pH values and compositions of water samples from different parts were tested.The process of crystal formation was simulated,the crystallization mechanism and its influencing factors were analyzed,and the corresponding countermeasures for the crystallization in drainage system were put forward.Results show that the main components of the crystal in the drainage system of railway tunnel are calcium carbonate minerals,which appear in the forms of calcite and spheroidal aragonite.The cement and high alkaline speed coagulant in the initial support shotcrete are the main sources of crystalline material,in which the Ca(OH)2 and other alkaline substances produced in the hydration process of cement are dissolved in groundwater and lost.Under the joint action of high temperature,high humidity environment condition of the drainage system and the change of CO2 partial pressure,the strong alkaline water body precipitates to form the calcium carbonate mineral crystals.By enhancing the sealing of the drainage system,the smoothness and stain resistance of the drainage interface,and improving the compactness of the initial support shotcrete,the crystallization blockage in the drainage system of railway tunnel can be alleviated.
作者
郭小雄
GUO Xiaoxiong(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2020年第1期71-77,共7页
China Railway Science
基金
中国铁路总公司科技研究开发计划项目(2015G002-F,2017G007-G,2017G007-K)
中国铁道科学研究院集团有限公司基金项目(2017YJ031)
关键词
铁路隧道
排水管结晶
排水系统堵塞
密封环境
耐沾污性
Railway tunnel
Crystallization of drainage pipe
Blockage of drainage system
Sealed environment
Smudge resistance
