Study On Structural Performance Of Widened With Geosynthetic Reinforced Soil

GRS(Geosynthetic reinforced Soil)is a kind of flexible composite with less than0.3m spacing,which can overcome the defects such as the stress concentration,the bulging of embankment slope and the crack of new and old roadbed in the existing slab of the traditional reinforced subgrade.The paper puts forward the GRS widening roadbed structure,adopts the Flac3 d numerical analysis method and the indoor static load model experiment,and analyses the performance of GRS widening roadbed deformation,settlement and stability.The soil arching law of reinforced soil is studied by soil arching effect experiment.The main work and conclusions of this paper are as follows:(1)The research progress of GRS structure,widening subgrade and reinforced soil solid project are investigated and analyzed.Using FLAC3 D to establish GRS widening subgrade model,the influence of slope rate,foundation type and filler type on the stability and stress of the model is analyzed.The results of numerical analysis show that the slope slope has obvious influence on the stress of the rib belt and the stability of the slope.Slope slope rate is increased 1 time times,slope stability coefficient is reduced by about 39%,the stress of rib zone is reduced by about 50%,and fly ash filling makes slope stability coefficient increase by about 17%,and the stress of rib belt is reduced by about 20%.(2)By using GRS to widen the static load model of Subgrade,the failure forms,lateral deformation,subsidence and stress of widening embankment slope on soft soil Foundation are analyzed.The experimental results show that the GRS widening embankment structure has stronger bearing capacity and better integrity,and its failure mode is the overall sliding crack of the slope along the end of the rib belt,and the rib has a strong restraining effect on widening the embankment slope of GRS,The lateral deformation of the slope is reduced by 46.7%,the uneven settlement at the joint of the new and old roadbed is reduced by 51% and the settlement at the top of the embankment is reduced by 26%.(3)The forming mechanism of soil arching effect,arching condition and arching law of reinforced soil structure are studied by reinforced soil arching experiment.The experimental results show that the soil arching effect exists in the reinforced soil structure in the adjacent slabs,and only when the reinforcement spacing is less than0.4m,the soil arching effect is formed by the stiffened soil in the panel;Further studies have found that the GRS structure at the top,the soil between the rib soil due to the small vertical stress,can not form the Earth arch;and at the middle and bottom,Soil arching can be formed between the ribs and soil.(4)The influence of reinforcement spacing,water content and foundation moduluson widening subgrade working performance was analyzed by flac3 d,and the adaptability analysis of GRS widening embankment was carried out.The results show that the smaller the spacing of reinforcement,the stronger the binding effect of the rib belt on the reinforced soil,the lower the lateral deformation of the slope is reduced by40.7% compared with the traditional reinforced soil structure,the vertical subsidence is reduced by 51% and the GRS settlement decreases by 51.8%;the higher the moisture content of the filler,the greater the lateral deformation and settlement of the embankment,The water content exceeding 19% will cause the slope to lose stability,the foundation modulus is bigger,the embankment settlement and the lateral deformation is smaller;the GRS structure can be used to widen the 8m and 12 m embankment.Through numerical analysis and model experiment,the paper studies the structure and performance of GRS widening roadbed,and the conclusions are of great significance for future solid engineering application and related subject research.