Experimental Study On Reinforcement For Flake Erosion Of Earth Sites With Moss In Arid Environment

In China,many earthen sites in the arid environment have flake erosion disease.This disease not only seriously affected the appearance of earthen sites,but also further developed into other diseases affecting the preservation of sites.In recent years,some scholars have put forward a lot of strengthening methods for the flake erosion disease,but in the practical application of this disease is still a lack of long-term effective reinforcement means.In this paper,the moss which is widely used in soil and water conservation and wind and sand control in recent years has been attempted to be applied to flake erosion reinforcement,in order to widen the application of the moss in earthen sites reinforcement in arid environment.Taking Guide ancient city of Qinghai as an example,using the moss to reinforce flake erosion.First,in the wild the nutrient solution was applied to promote the growth of moss,and the changes of surface insertion resistance were measured before and after the growth of moss.Then,the reinforced effect and solid soil effect of moss were analyzed in the laboratory;and the differences in the water stability of the moss crust and the flake erosion crust were analyzed.Finally,the soil layer is divided into six sub layers,the microstructure,mineral composition,particle size and salt content of each soil layer was analyzed from microscopic view before and after the growth of moss.The results of the various tests are as follows:(1)Field test found: sticky rice slurry,especially the concentration of 2% of sticky rice slurry can promote the growth of moss.After the growth of moss the surface insertion resistance of Great Wall increased by 56.51%,Minor cracks in the wall have also been repaired.(2)Laboratory test show that: The moss on the Great Wall has a reinforcement effect on the flake erosion soil.Moss can strengthen the soil around the root system,the weight of the soil which been reinforced was 3000 times greater than that of the weight of moss.After moss strengthening,the anti-erosion ability of the crust layer was greatly improved,and the resistance to disintegration has been increased significantly.(3)Microscopic experiments show that: the moss has a lot of fibrous roots,it will be tied to the eroded soil,and strengthen the connection between the cortex layer and the rammed earth layer.During the growth process of moss,the mineral composition of the soil will not be changed,and the migration of different minerals in the soil layer will not be promoted.Moss growth will produce weathering on the earth sites,so that the soil particles smaller,but this weathering did not reduce the strength of the earth sites.The growth of moss can absorb salt and promote the migration of salt layers,and reduce the salt content in the salt of the powder layer,which can effectively restrain the regeneration of the erosion disease.All kinds of test results show that soil strength,anti-erosion performance and engineering properties can be improved after moss growth.Therefore,it is feasible to use moss to reinforce the flake erosion of earthen sites in arid environment.Moss as a new method and new material for the protection of earthen sites,it has certain theoretical significance and engineering guidance.