Study On Strength Characteristics And Application Of Wheat Straw Reinforced Soil

As an effective soil reinforcement technology,reinforced soil has been widely used in the field of geotechnical engineering,and the types of reinforced materials are also increasingly diverse.Among them,the use of natural crops as reinforcement materials has been for a long time,but the research and application of natural crops are relatively few at present.In this paper,wheat straw reinforcement materials as the research object,and the optimum reinforcement mode,effect and mechanism of wheat straw reinforcement were studied by laboratory and model tests.The main contents and conclusions are as follows:(1)Through the unconfined compressive strength test,the deformation and failure characteristics of plain soil and reinforced soil are studied and compared.The results show that the reinforcement effect of wheat straw bar can only be reflected when the axial strain is developed to a certain extent.The effect of reinforcement in the soil can reduce the tendency of crack formation in the specimen,and the failure form of plain soil is shear failure along the shear plane.The reinforced soil shows the plastic failure of the whole.(2)In the unconfined compressive strength test,the stress-strain curve of wheat straw reinforced soil is softening type.In a certain range of reinforcement length and reinforcement ratio,the peak strength and residual strength of reinforced soil are higher than that of plain soil.According to the experimental results,the optimum reinforcement length is 15 ~ 25 mm,and the reinforcement ratio is 0.3%.(3)Through the model test,the reinforcement effect of wheat straw bar on silty clay slope is simulated,and the displacement and deformation characteristics of plain soil slope and wheat straw bar reinforced slope are compared.Under the same load,the horizontal deformation of the reinforced soil slope outer retaining wall is smaller than that of the plain soil slope external retaining wall,and the displacement of the plain soil slope outer retaining wall will appear "sudden change",while the reinforced soil slope outer retaining wall deformation is gradual and continuous.(4)When the load on the top of the slope is small,there is little difference between the soil pressure on the plain soil slope and the reinforced soil slope retaining wall.With the increase of load,the back earth pressure of reinforced soil slope retaining wall is obviouslyless than that of plain soil slope retaining wall under the same load,which indicates that wheat straw reinforcement is added to bear and disperse a part of earth pressure.(5)The failure patterns of plain soil slope and reinforced soil slope are different.The sliding angle of plain soil slope is larger,the slip surface is short and steep,while the potential Sliding angle of reinforced soil slope is smaller.When the retaining wall fails,the backfill of the wall will collapse along the sliding surface,while the reinforced soil slope will "crack but not fall",the stability is better.