Experimental study of geotextile's drainage and filteration propertis under different hydraulic gradients and confining pressures
Experimental study of geotextile's drainage and filteration propertis under different hydraulic gradients and confining pressures
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发表时间：
2011-06
影响因子：
1.7
通讯作者：
Pak Ali;Zahmatkesh Zahra
中科院分区：
文献类型：
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作者：
Pak Ali;Zahmatkesh Zahra
土工布是过滤和排水应用最广泛的合成材料之一。由于在实际应用中，土工布受到各种水力梯度和围应力的作用，因此土工布在不同情况下的水力性能具有重要的实际意义。采用标准介电常数和透射率仪，研究了不同性能、单位面积质量分别为200g/m2、400g/m2、500g/m2和800g/m2的非织造针刺土工布在不同围应力和水力梯度下的过滤排水性能。在10cm ~ 60cm的水头和1000kPa的围应力作用下，研究了制备好的试样的水力特性。本文研究了土工布纤维的流动规律和土工布渗透性能的各向异性。结果表明：随着法向应力的增大，透光率呈指数型减小，直至达到某一残余值；介电常数和透光率系数随水力梯度的增大而减小；在所有情况下，流型都是非湍流的。土工布的水力性能在填埋盖设计、堤防和灌溉结构排水系统设计以及河流工程防护系统设计中具有重要的应用价值。
Geotextiles are one of the most widely used synthetic materials in filtration and drainage applications. Since in real applications, geotextiles are subjected to various hydraulic gradients and confining stresses, hydraulic behavior of geotextiles under different circumstances is of great practical importance. In this study filtration and drainage properties of several nonwoven needle-punched geotextiles with different properties and unit mass per area of 200g/m2, 400g/m2, 500g/m2 and 800g/m2, under various confining stresses and hydraulic gradients, were studied using standard permittivity and transmissivity equipments. Prepared samples were subjected to hydraulic heads in the range of 10cm to 60cm and confining stresses up to 1000kPa and their hydraulic behavior was investigated accordingly. In this study the flow regime through the geotextile fibers and also the anisotropic behavior of geotextile permeability were investigated. The results show that transmissivity will decrease exponentially with increasing the normal stress until a residual value is reached, and permittivity and transmissivity coefficients were seen to decrease with increasing the hydraulic gradient. The flow regime has found to be non-turbulent in all cases.The Geotextile hydraulic behavior is of great usage in the design of landfill covers, design of embankments and irrigation structures drainage systems, and in the design of protection systems in river engineering.