Experimental Study On Mechanical Property Of Geogrid Reinforced Soil

As the reinforced earth emerges,it has been paid enormous attention and widely used in modern geotechnical engineering due its superiority in many categories like the strong adaptability,cheap but friendly to ecological environment protection.However,the interaction effect between the reinforced material and filler is extremely complex,and the working mechanism,the stress deformation and the reinforcement characteristics of geotechnical-grille reinforced soil structure are lack of intensive study.Also the mechanical mechanism of various subgrade reinforcement is not fully understood,and research on engineering response and mechanical behavior under various loads,especially traffic dynamic loads are lack of intensive study,which has restricted the application of reinforced soil technology in practical engineering.This paper is based on the analysis on local stress of geotechnical-grille reinforced sand and crushed stone soil by means of the the axial local monotonic loading test and axial local cyclic loading test.With the help of a large dynamic three axis instrument,the modulus of resilience of geogrid reinforced gravel soil specimens with different moisture content and different reinforcement methods is tested?Based on the analysis of the influence of different factors on the stress and deformation of the geotechnical-grille reinforced soil,the main conclusions are as follows:(1)The local monotonic loading test of reinforced sand and gravel soil shows:After the soil reinforcement,the Local compression capacity can be improved to a certain extent,and the reinforcement effect of reinforced crushed stone soil is better than that of reinforced sand;The variation law of load and vertical displacement of reinforced river sand is different from that of reinforced crushed stone in the process of local monotonic loading;And it shows that with the increase of the moisture content of the specimen,the local compressive capacity decreases.(2)The cyclic loading test of reinforced sand and gravel soil shows:The curves of vertical displacement and loading cycle can be divided into two stages:compaction stage and stable development stage;The reinforced earth has a better performance on resistance to local deformation;With the increase of the moisture content,the ability of local deformation of the specimen decreases;The loading sequence has some influence on the results of cyclic loading;Under the same conditions,the larger the loading frequency,the smaller the local deformation of the specimen.(3)The dynamic modulus of elasticity can be increased after the soil reinforced;The geotechnical-grille placed on the surface of the specimen has a significant effect on improving the dynamic modulus of elasticity,while only one layer of geotechnical grille placed in the middle of the specimen,the effect of increasing the dynamic modulus is not significant.The increase of moisture content can reduce the dynamic modulus of elasticity;The effects of deviatoric stress,confining pressure,body stress and eight body shear stress on the dynamic modulus of elasticity of the specimen are the same,under the same conditions,the dynamic modulus increases with the increase of dynamic modulus;The results of the experiment are regressed according to the NCHRP 1-28A model,and the rationality of the model is verified.