水力梯度对土-无纺织物系统反滤性的影响

Test Research on Filtration Properties Between Nonwoven Geotextile and Soil System Under Different Hydraulic Gradient

为研究土工织物的反滤性能,针对其淤堵问题,选取5种土工织物与宁夏引黄灌区土质组成反滤系统,对水力梯度从4逐渐升至7再逐渐升至11和直接升高至11两种方式进行了梯度比试验,测量了土与织物系统的渗透系数、梯度比、织物单位体积含土量、渗土量等。结果表明:(1)黑色丙纶试样(2#)在水力梯度逐渐升高时比直接升高时渗透系数大,白色人革基布(1#)、长丝(聚酯3#)、绿色丙纶试样(5#)系统渗透系数随着水力梯度的升高而减小;(2)当水力梯度逐渐升高时,白色丙纶试样(4#)和黑色丙纶试样发生淤堵,当水力梯度直接升高到11时黑色丙纶试样发生淤堵;(3)水力梯度直接升高至11时,黑色丙纶和白色丙纶织物单位体积含土量减少。

Gradient ratio testswere carried out to study the filtration characteristic influence of geotextiles. The filtration systems were composed of the geotextiles and soils in Ningxia. Gradient ratio test under three kinds of 4,7 and 11 average hydraulic gradients with gradually and directly increases was carried out to measure the permeability coefficient of soil and fabric systems,phase soil infiltration capacity and gradient ratio. The results show that a) when i gradually increase,No.2 have bigger permeability coefficient than i directly increased,No.1,No.3 and No.5's permeability coefficient decreased with increasing i; b) when i gradually increases,No.4 and No.2 are clogging. When i directly increase,No.2 is clogging; c) when i directly increase,No.2 and No.4 have smaller soil content per unit volume of geotextiles than i gradually increases. The others showed the tendency of increasing.