土工袋柔性挡土墙模型试验研究

Model Test on Retaining Wall Constructed with Soilbags

使用土工袋构筑而成的挡土墙具有一定的柔性,可以通过一定的变形,有效地减小墙后土压力,增加挡土墙的安全性。土压力大小与墙体的变位模式有着密切关系,且是进行挡土结构物断面设计和稳定验算的重要荷载。通过对土工袋柔性挡土墙模型的设计和试验观测,发现:墙体的位移模式和墙后填土的破坏模式是由平动和转动两种模式组成的;土工袋柔性挡土墙模型的土压力竖向分布接近库伦主动土压力;土压力沿水平方向的传递规律为由内到外递减。最后,根据试验结果分析解释了土压力削减的原因,并建立了相应的力平衡关系式。

The retaining wall composed of soil bag has certain flexibility and can have lateral distortion under the pressure,which can reduce the pressure effectively and increase the safety of retaining wall.Earth pressure is an important load for the section design and stability check of retaining structures,and it is directly relevant to the wall displacement mode.A model test was performed on a retaining wall constructed with soilbags,which showed that（1）the deformation mode of the wall and the failure mode of the backfill soil are composed of translational and rotary modes;（2）The vertical distribution of earth pressure of the retaining wall composed of soilbags is close to Coulomb active earth pressure;and（3）the earth pressure decreases from the inside out along the horizontal direction.A force balance equation was established to explain the horizontal decreasing of the earth pressures within the retaining wall.