Interactionbetweendifferentimperviousmaterialsandaquatic Plants

As people pay more and more attention to environmental protection and sustainable development,the full and reasonable utilization of water resources has received widespread attention.In order to restore the environment and purify water quality,people often establish artificial ecological anti-seepage systems and plant aquatic plants.At the same time,the role of plant roots will affect the performance of impervious materials,thereby affecting their impermeability.In this paper,GCL?Geosynthetic Clay Liner?is compared with traditional impervious materials geomembrane and compacted clay,and an impervious system composed of impervious materials,overlying soil and aquatic plants is established,through the model test,the influence of plant root system on the anti-seepage performance of GCL was studied.It can be concluded as follows:?1?Through artificial lake model test research,three emergent plants of re-flowering,reed and cattail were planted.GCL,geomembrane and compacted clay were selected as the impervious layer,and the number of budding plants,growth height and coverage were recorded.The results showed that:in the early stage of plant growth,the laying of impervious material had no obvious effect on plant sprout and growth;in the later stage of plant growth,the GCL impervious layer was beneficial to the growth of three aquatic plants,and the effect on re-flowering was most obvious.Geomembrane has a certain inhibitory effect on the later stages of plant growth;?2?Through the GCL moisture content test and free expansion test,the effect of plant roots on GCL moisture content and free expansion was studied.The water content test shows that:the water content of GCL in the original state is 20%.The water content of GCL under the normal root system is about 6.8 to 9.2 times the water content of the GCL in the original state.The maximum value is 183%.The moisture content is about 3to 4.7 times the GCL moisture content in the original state,and the maximum value is94%.The free expansion test shows that:whether the root system is withered or not,its free expansion index is between 5.5 and 7.8,which is the original state.0.33 times.Root diameter does not affect changes in water content and free expansion;?3?Through the GCL penetration test,the changes of GCL permeability coefficient under normal root action and withered root system were studied.The test showed that:under the same confining pressure,the penetration of the root system can increase the permeability coefficient of GCL.When the root diameter is small,GCL still has good anti-seepage performance.When the diameters of erect flower,reed and cattail penetrating GCL are greater than 11.04mm,8.18mm and 8.09mm,the maximum permeability coefficient reaches 1.05×10^-7m/s.For roots of the same diameter,the permeability coefficient of GCL after root wilt is about 1.1-1.7 times that of normal roots.Withered roots have a greater impact on the anti-seepage performance of GCL.