Waste Tyre Pieces Of Reinforced Subgrade Mechanical Properties Experimental Study

With the rapid development of automobile industry,the number of cars has increased dramatically,and then also brought another worth thinking deeply—an increasing number of waste tires.Because the old tires have more influence on the environment.Waste tyre has gradually become a concern of the international community.They affect the environment and social economy problems.After using mechanical cutting evenly mixed with waste tires into the sand,they can be used as a new geotechnical materials to alleviate the influence caused by waste tires for the environment.At present,academia for the understanding of the pieces of scrap tire reinforcement mechanism is not very clear.The calculation problem of the tire debris reinforced theory is relatively lack.These pieces of pressing problems hampering the scrap tire in the application of the reinforcement engineering.In this paper, based on the experience of the developed countries deal with waste tires.Combined with the region’s soil basic physical properties.Through lab large-scale direct shear test,reinforced embankment indoor model test.The applicability of the constitutive model is studied.The reinforcement mechanism of tire debris and reinforcement method, the reinforcement effect factors were studied.Through a series of experiments.I can draw some conclusions,these conclusions put forward reference for engineering practice. This paper mainly includes the main research contents and results:(1)Large direct shear test of tire debris and sand reinforced soil research results show that the interface shear mechanics.Tire debris and soil interface shear stress is worth to improve,in the early stages of the shear,the shear stress increases with the increase of the shear displacement,When the shear stress to the peak,shear stress has a tendency to decrease,but the decrease rate is slow.The shear stress values reached a steady value.With the increase of soil moisture content.The peak shear stress also increases accordingly.Tyre pieces under different moisture content and normal stress reinforced shear stress and displacement relationship curve is similar to the overall trend.(2)Tire debris reinforcement has a significant influence on subgrade stress evolution.When the subgrade damage occurs,reinforced embankment model does not appear obvious plastic flow,the stress of each measuring point without a significant decline,without reinforcement subgrade model plastic flow occurs.Pressure box data appear relatively steep fall significantly.(3)By comparing reinforced embankment with no reinforced embankment,the stress distribution are basically identical,but reinforcement can significantly reduce the additional stress value of the soil.And tyre pieces of content at 5% is the best.Additional stress value decreases.(4)Tire fraction reinforcement of subgrade settlement is very obvious,when the tire reinforcement fragments content increases gradually,the effect is more and more significant.Reinforcement effect is the best when the tire debris content reached 5%.Continue to increase the content, the effect is reduced.Reinforcement layer thickness show similar patterns.Reinforcement layer thickness increasing, the effect is remarkable,when the reinforced layer thickness to 15 cm, the optimal reinforcement effect.In 10 cm soil layer thickness, reinforcement effect is the most significant.(5)The subgrade failure mode:There was an obvious phenomenon of uplift loading plate on both sides of the soil,middle concave and convex on both sides.On both sides of loading plate have obvious cracks.Cracks are relatively wide.Reinforced sand damage cracks are much smaller than the pure sand subgrade.Reinforcement technology limits the lateral deformation of subgrade soil.