Study Of Mechanical Properties Of Tree Root Reinforcing Soil

Roots in forest ecosystems play the roles of retaining plants, absorbing water and solubling minerals in water, and also can be able to prevent shallow landslides, soil and water retention. This article is adopted by the roots of the four common trees in North China Mountainous Area in10000axial fatigue tensile test about Chinese pine, larch, birch, and Mongolian oak which is3,5,7mm diameter,to get the determination of tensile mechanical properties of single root fatigue before and after. The qualitative analysis of the impact of the diameter, species and other factors at the root fatigue before and after the maximum tensile strength, tensile strength and stress-strain relations. Then,selected four species roots as3,5,7mm diameter test root like Mulan Paddock of North China retrieved soil samples with the preparation of the complex into the root soil sample, using automatic triaxial compression meter complex shear test research and analysis of complex shear characteristics,evaluation of the enhanced role of the shear strength of the soil root diameter, tree species, and buried roots way.The main research results are as follows:(1) The average size of the order of the maximum tensile strength of four kinds of tree roots before the fatigue test:birch> mongolian oak> pine> larch. Looping10,000times, the greatest change in tensile strength is Pinus tabulaeformis,then larch and mongolian oak,the the last is birch.After fatigue test,four kinds of tree roots maximum tensile strength of the average size of the order:Mongolian oak> birch> pine> larch.(2) Before fatigue test,four species root tensile strength with increasing diameter decreases,takes on a power function relationship.The tensile strength of the four species is birch> Mongolian oak> pine> larch. After10000fatigue tensile test, the tensile strength of the order of the four kinds of tree roots: birch> mongolian oak=pine> larch. This is essentially unchanged before fatigue test. There is the description that fatigue but not enough to change the impact of the species itself that the root structure of the composition have an impact on a single tensile strength of the species, the species is still a very important factor affecting root tensile strength characteristics. Roots after the10000fatigue have bigger maximum tensile strength and tensile strength than the same root diameter before test. It shows that the low cycle fatigue under the action of the root system in the nature of the Chinese Pine water or storm destructive, not only decreases its own tensile performance,but also contributes to the improvement of its tensile properties and enhanced root solid soil capacity.(3) Triaxial compression test results show that the root system can significantly improve the shear strength of the soil. Buried in the soil increased root diameter, root soil complex internal friction angle and inner cohesion also increases and soil shear strength is strengthened.Adding roots can significantly improve the ability of the soil to resist shear.(4) The arrangement of the enhanced role of the root diameter of the roots in soil samples have a great relationship. Same as the buried roots way, the composite root complex shear strength values compared to the other two buried root shear strength increased significantly. Three forms of horizontal root, vertical root and composite root type, soil shear strength increased order is:composite root complex>the level root complex>vertical root complex. It shows that the composite root in enhancing soil strength effect is most significant, and the composite root forest tree species is best suited to enhance the strength of the soil to maintain soil stability.