柔性浅基础下变刚度垫层设置的有限元分析

Finite Element Analysis for Flexible Shallow Foundation with Variable Rigidity Cushion

柔性浅基础不具备调整地基变形的能力,针对这一缺点,可在基底应力较大的部位设置强度较大的垫层,而在应力较小的部位设置强度较小的垫层,即通过在基底设置中心刚度大、边缘刚度小的变刚度垫层,以有效调整地基土的应力分布,改善地基土工作性状。采用PLAXIS 2D有限元软件,分析比较了柔性浅基础下设置不同工况的变刚度垫层对地基土中应力分布及基础差异沉降的影响,发现在基底中部0.5～0.6倍基宽范围内设置变刚度垫层时,差异沉降控制效果最好。

Flexible Shallow foundation doesn＇t have ability to control displacement of subsoil. This problem can be solved by putting the cushion with lower strength on both sides of foundation soil and cushion with higher strength on the central. And that is to use higher strength cushion to resist the bigger pressure and lower strength cushion to resist the smaller pressure. The influence of variable rigidity cushion on contact pressure, stress distribution in subsoil and settlement of foundation is studied by using the Plaxis 2D finite el ement analysis software. It is found that rigidity cushion set at the center of bottom of foundation about 0.5B to 0.6B would be the best result to control differential settlement.