隧道排水土工织物抗淤堵性能模型试验研究

Model Test Study on Anti-Clogging Performance of Geotextile for Tunnel Drainage

在富水隧道的长期运营中,防排水体系中的土工织物经常会发生淤堵问题。为解决隧道排水系统在运营过程中由于土工织物淤堵导致排水性能失效的难题,分析现有土工织物淤堵试验的不足,并结合隧道拱形断面和隧道环向排水管间隔布置等结构特点自主设计研发隧道土工织物淤堵室内试验装置,对土工织物类型、层数和淤堵类型等因素展开试验研究。试验结果表明:1)同一隧道横截面下,土工织物拱腰处的单位时间流量大于拱肩和拱顶处,拱腰处淤堵程度最严重;2)聚酯长丝和涤纶短丝土工织物的抗化学淤堵性能和抗物理淤堵性能基本相同,但聚酯长丝土工织物的透水性能和保土性能优于涤纶短丝;3)随着土工织物层数的增加,土工织物整体排水性能和抗淤堵能力增强,提升幅度逐渐减小;4)位于环向排水管外侧的土工织物的淤堵程度较为严重;5)土工织物受化学淤堵的影响强于物理淤堵。

The phenomenon of geotextile clogging often occurs in the waterproof and drainage system during the water-rich tunnel operation.To solve the problem of drainage performance failure caused by geotextile clogging during the tunnel drainage system operation,the shortcomings of existing geotextile clogging tests are analyzed.Therefore,an indoor scale model test device for tunnel geotextile clogging is designed and developed based on the characteristics of tunnel arch section type and indirect arrangement of circular drainage pipe.Then,the seepage and clogging tests are conducted on the types and layers of geotextiles and clogging types.The test results show the following.First,the unit time flow at the arch waist is greater than that at the arch shoulder and the arch crown for the geotextile at the same cross-section of the tunnel;moreover,the clogging at the arch waist is the most severe.Second,the chemical and physical resistances of polyester filament and staple geotextiles are the same.However,the water permeability and soil retention of polyester filament are better than that of polyester staple geotextile.Third,with the increasing geotextile layers,the overall drainage performance and anti-clogging ability of geotextile increase,and the increasing range gradually reduces.Furthermore,clogging of the geotextile above the circular drainage pipe is more severe.Finally,the influence of chemical clogging on geotextiles is larger than that of physical clogging.