Tensile Model Analyses Based On Eight Plant Roots

There is no doubt that bio-slope-engineering become more and more popular because of its pro-environment, inexpensive price, sustained action and the low of maintenance costs compared with engineering revetment. Root play an important role in bio-slope-engineering, and the acting force between root and soil is the core force of bio-slope-engineering research. There are two research methods about soil reinforcement of roots. One method regards root and soil as a new material, and the new material will make some changes in the cohesion and the internal friction angle compared with original soil. The other method regards the taproot as a rock bolt, and the lateral root can reinforce the soil. The soil fixation force comes from the friction between root and soil.Generally speaking, root system contains tap root system and fibrous root system. The roots of herbaceous plants are a part of fibrous root system, and the roots of woody plants are a part of tap root system. The roots of herbaceous plants contain adventitious roots and lateral roots. The roots of woody plants contain taproots, lateral roots and tertiary roots. In this paper, we select Sedge, Ophiopogogon japonicus, Zoysia japonica, Green bristlegrass, Ligustrum lucidum, Cedar, Orange tree and Osmanthus fragrans as research subjects to do experiments.In the mechanical analyses of soil-reinforcement of roots, in order to explore the effect of plant roots, some experiments and models had to be done. Firstly, by the composition test of the eight plant root systems, some results are accepted. The representative parameters contain the length of roots, the diameter of roots, the angle of the roots and the density of the roots. Such are the physical parameters of the models. Secondly, through the trial of ultimate tension, we get the mechanical results of the eight plant roots. Such are the mechanics parameters of the models. Thirdly, according to the results of the composition test and the ultimate tension trial, we make the cylindrical roots model and the obconical roots model. By the analyses of the models, the effect of herbaceous plant about the force of the lateral root cannot be neglect. And the effect of woody plant about the force of the lateral root and the tertiary root cannot be neglect either.