Study On Mechanical Properties Of Interaction Of The Corn Stubble And Soil

China owns vast cropland, thus promising a broad prospect in the development ofstraw-fired cogeneration. The separation between stubble and soil will directly affect theefficiency of cogeneration at later stage and erosion control. Therefore, it’s importantthat studying on mechanical properties of the Corn roots. Through field excavations,tensile test and triaxial shear tests on corn roots, pull resistance mechanicscharacteristics, shear property and effect of different factors on tensile property andshear property on roots of Corn has been studied. Mechanism of corn root in theenhancement of shearing strength of soil was analyzed in order to provide a referentialbasis for the development and promotion of root-soil separator.Under external force, stretching resistance on single root of corn gradually increasewith increasing root diameter by power function; the tensile strength of corn single roothas a negative correlation with root diameter. Analysis of the stress strain curves of theroot system indicates that, as a startup, the strain increases linearly with increasingstress, when the stress more than elastic limit, single into plastic deformation, the curveis relatively smooth. Gauge length, loading rate and the season are three importanteffects of single tensile properties of corn..With increasing gauge length under the samediameter， the tensile strength and stretching resistance of root decreases. The greaterdiameter, the bigger differences in stretching resistance, and tensile strengthperformance in contrast; in the greater loading rate, the maximum tensile strength andstretching resistance is smaller, with diameter increasing, the difference in stretchingresistance under different loading rate is more obvious, tensile strength performance incontrast; in different season and the same diameter, stretching resistance and tensile strength of corn that was collected in October autumn are larger than that April spring,with the increase of diameter, the difference in stretching resistances and tensile strengthare also increased.The stress strain curves of root-soil complex are nonlinear relationship, and thecomplex show obvious elasto material properties; in different experimental conditions,the shearing strength and cohesion force of the complex are greater than in pure soil;with the increase of the water content, the shearing strength and cohesion force of thecomplex perform reduce trend performance, and the internal friction angle of thecomplex does not change significantly; the shearing strength, cohesion force and theinternal friction angle of the root-soil complex are increase with increasing dry densityof soil; the shearing strength and cohesion force of the composite root> vertical root>horizontal root> pure soil; along with the increase of the roots, the shearing strength,cohesion force and the internal friction angle of the root-soil complex are increase.Analysis of the relationship between growth rate of the limit principle stress differenceand confining pressure stress, the root system in epilimmion earth has obvious effect,and to deeper layers, its effect decreased obviously.