岩溶区隧道排水管道结晶沉淀水动力影响因素试验研究

为揭示岩溶区隧道排水管结晶致堵机理,并探究水动力影响因素对管道结晶沉淀发育的影响规律,设计了以管道水动力因素为观察变量的模型试验,具体为:排水管道铺设坡度为3%、4%、5%的对照试验,液面高度为7.2mm、10.2mm、13.3mm的对照试验,管道内壁摩擦系数为0.12、0.21、0.53、0.65、0.69、0.83的对照试验。岩溶区隧道排水管结晶沉淀规律具体表现为:随着管道铺设坡度的增大,结晶沉淀速率逐渐减小;随着排水管道内壁液面高度的增大而减小;随着排水管道内壁摩擦系数的增大而增大,且管道内壁摩擦系数对管道结晶沉淀速率的影响有限。通过试验分析表明:控制岩溶区隧道排水管道沉淀结晶的并不完全是DBL层厚度,而水动力因素中液体流速、液面高度以及排水管道内壁摩擦系数等因素也会对排水管道沉淀结晶速率产生重要影响。

Research on the Influence Factors of Crystallization and Sedimentation of Tunnel Drainage Pipeline in Karst Area

In order to reveal the mechanism of crystal plugging of tunnel drainage pipes in karst area and explore the influence law of hydrodynamic factors on the development of crystal precipitation of pipes,a model test is designed with the hydrodynamic factors of pipes as observation variables,specifically the control experiment with the laying slope of drainage pipes of 3%,4%and 5%,the control experiment with the height of liquid level of 7.2mm,10.2mm and 13.3mm,and the friction coefficient of the inner wall of pipes of 0.12,021,0.53,0.65,0.69and 0.83.The results show that the crystal precipitation rate of tunnel drainage pipe in karst area decreases with the increase of pipeline laying slope,decreases with the increase of liquid level on the inner wall of drainage pipe,increases with the increase of friction coefficient on the inner wall of drainage pipe,and the influence of friction coefficient on the crystal precipitation rate is limited.In addition,the experimental analysis shows that the thickness of DBL layer is not the only factor to control the precipitation and crystallization of tunnel drainage pipeline in karst area,and the application of DBL theory should have certain preconditions,while the hydrodynamic factors such as liquid velocity,liquid level height and internal friction coefficient of drainage pipeline will also have an important impact on the precipitation and crystallization rate of drainage pipeline.