Mesoscopic study on mechanical behavior evolution and deformation mechanism of overlying reinforced subgrade in subsidence area
In order to reveal the mechanical behavior evolution and deformation mechanism of reinforced subgrade in subsidence area,a discrete element model of reinforced subgrade in subsidence area was established based on laboratory tests.From the mesoscopic level,the distribution of contact force chain between particles,relative displacement between particles,bending deformation and tension of reinforcement,and soil arch ratio under different reinforcement length,subsidence width and subgrade height were analyzed.The influence of reinforcement length,subsidence width and subgrade height on the mechanical behavior and deformation mechanism of reinforced subgrade was explored.The results show that a reasonable length of reinforcement material can make the reinforcement effectively bear the load of the upper subgrade and limit the relative displacement between the subgrade fillings.In this study,the effect of limiting the relative displacement of subgrade filling is the best when the length of reinforcement L=500 mm.Moreover,the tension of the reinforcement reaches the maximum value,the bending deformation of the reinforcement reaches the minimum value,and the shape of the particle contact force chain is shown as a complete arch.Under the condition of the same anchoring ratio,the larger the subsidence width,the lower the degree of soil arching effect,the smaller the soil arching ratio,and the shape of the particle contact force chain evolves from a complete arch to two unclosed bevels.With the increase of the subsidence width,the deformation range of the subgrade and the deformation of the reinforcement gradually increase,and the reinforcement effect gradually weakens.With the increase of subgrade height,the degradation of soil arching can be effectively restricted and soil arching effect is fully shown.The shape of the contact force chain among the particles evolves from two inclined edges with a certain angle to the bottom of the subgrade to a complete arch.The tensile forces along the reinforcement increase gradually,while the horizontal and vertical displacements of the reinforcement decrease gradually.Additionally,the shape of the subgrade deformation range changes from rectangular to annular ellipse with the width almost unchanged.
reinforced subgradelocal subsidence areageotextilemechanical behaviordeformation mechanismdiscrete element modeling
国家科技期刊平台
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