岩溶隧道排水管结晶堵塞除垢试验及数值模拟研究

Study on Crystal Clogging Descaling Test and Numerical Simulation of Karst Pipeline

岩溶区隧道渗水的总硬度和溶解性总固体含量较高且渗入量大,隧道排水管普遍存在结晶堵塞现象,从而引发一系列隧道病害问题,严重威胁隧道的建设及运营安全,迫切需要开展针对性的除垢技术研究。以某岩溶区隧道排水管道结晶堵塞现象为原型,针对岩溶管道堵塞进行水动力冲刷除垢设计并开展室内试验,同步构建考虑水动力冲刷过程的变边界管道水动力除垢数值模型,通过试验数据拟合,验证了模型的适用性和可靠性。结果表明,变边界管道水动力除垢数值模型能定量模拟冲刷除垢过程,初期冲刷效果较好,随着时间的推移,冲刷率逐渐降低至稳定的低值,有效冲刷面积达64%,该研究可为现场开展管道结晶堵塞水动力冲刷除垢提供理论支撑。

High total hardness and total dissolved solids of the groundwater seeping into the tunnel drainage pipeline in karst areas results in crystallized blockage,which will cause a series of tunnel diseases and seriously threaten the safety of tunnel construction and operation.It is essential to carry out the targeted research on crystal clogging descaling technology.In this paper,a 1∶1 equal laboratory experiment was designed to investigate crystal clogging descaling by hydrodynamic scouring.Meanwhile,a novel variable boundary pipeline descaling simulation model considering the hydrodynamic scouring process was developed for calculating the denudation rate of CaCO3fouling in pipeline surface.The applicability and reliability of the model were verified by fitting the test data.The experiment and simulation results show that the numerical model can effectively simulate the descaling process.The scouring rate gradually decreases to a stable low value with time and the effective scouring area can reach 64%.The simulation model can provide technical support for crystal clogging descaling by hydraulic washing.