Research On Bearing Capacity Of Waste Rubber Tires Piles Composite Foundation

Medium material pile is widely used in soft ground reinforcement engineering because its conveniently,simple construction,low cost,improve the bearing capacity of foundation,accelerate the soft foundation consolidation,reducing subsidence etc.Medium material limited bearing capacity of pile depends mainly on the maximum confining force provided by the soil around pile,When the strength of soil around pile is low,medium material pile is prone to larger bulge deformation which lead to the failure of composite foundation.Studies have shown that:The local base soil strength is too low(generally considered undrained shear strength c<20kPa),it can not provide the needed radial binding to keep the gravel pile work will not reach the purpose of strengthening the foundation.For the purpose of giving full play to the potential bearing and advantage of granular material,The granular material can be filled in the waste tire inner.Because of high ring and radial tensile strength of the rubber tires,they can reinforce the anti-shear ability of granular material and effective control of pile body bulging deformation under load.Thus it can improve the bearing capacity of composite foundation.The composite foundation.In order to study the bearing capacity characteristics,load transfer mechanism,failure form of tires pile composite foundation,This article is based on the indoor test data,Used the FLAC3D simulation software to study the different soild around pile and different sdubstratum influences on the tires pile composite foundation,obtained the following conclusions:(1)The better mechanical properties of soil around pile,the bearing capacity of tires pile composite foundation is more larger,but compared with the discrete material pile,the influence of soil around pile on pile bearing capacity greatly decreased.(2)Because the tire has the strong ability to ring hoop pile,the load transfers to the layers of composite foundation.load influence depth is generally between 3-4m.(3)In the top plane of tire pile,the stress is saddle-shaped which are middle small and margin large,when the load is small.(4)The bulging deformation depth of granular material pile is generally happened in the range of 1～3 times the pile diameter,but the tires pile deformation range is about 5.9 times of the pile diameter.(5)Under load,the soil in tires piles occurs shear deformation,because the hoop effect of tires,which has not formed through sliding surface.(6)When the pile length reaches a certain value,the compression modulus of the underlying soil has no effect on the ultimate bearing capacity of the pile and have little effect on the pile top settlement.(7)When the compression modulus ratio of the soil in pile the and the soil around pile is larger,most the destruction form of tire pile composite foundation is bulging damage.