华南地区灰岩隧道排水管化学结晶淤堵试验研究

Experimental Study on Chemical Crystallization and Siltation in Drainage Pipe of Limestone Tunnel in South China

隧道排水系统的结晶堵塞始终是隧道施工与运营管养技术人员面临的技术难题,处治费用很高,排水孔堵塞对隧道施工过程或者运营期间有较大的安全威胁。文章借助模型试验对隧道结晶淤堵过程及变化规律进行探究,与现场试验比对分析得出:(1)CaCO_(3)结晶体纯度高且水流速低时,结晶沉淀物有充分时间停留在排水管壁且易粘附在管壁内表面,结晶体更加容易堆积并堵塞,结晶淤堵速率加快,反之结晶淤堵速率变慢。(2)模型与现场试验在同等测试条件下得出的隧道排水管第一、第二养护时间节点是一致的,从而验证了模型试验结果的正确性。

The crystallization and siltation in tunnel drainage system is always a technical problem for tunnel construction and operation management and maintenance technicians and the treatment cost is very high.The siltation of drainage holes causes great potential safety hazards during tunnel construction or operation.In this paper,the process and change law of tunnel crystallization and siltation were investigated through the model test.Compared with the field test,it is concluded that:(1)when the purity of CaCO_(3)crystal is high and the water flow rate is low,the crystal sediment has sufficient time to deposit on the drainage pipe wall and easily adheres to the inner surface of the pipe wall and the crystal might more easily form accumulation and blocking so that the crystallization and siltation rate is accelerated.On the contrary,the rate of crystallization and siltation might slow down.(2)According to the model test and the field comparison test,the first and second maintenance time nodes of tunnel drainage pipes obtained by the model and field tests are consistent under the same test conditions,which has verified the correctness of the model test results.