聚氨酯级配碎石层特性研究

针对高速列车荷载与水耦合作用下级配碎石层水致损伤问题，通过室内模型试验，探讨水环境-动载耦合作用下，聚氨酯级配碎石层的长期受力和变形规律，得出如下结论:聚氨酯掺量达到8 %时，聚氨酯级配碎石孔隙率达2 %左右，聚氨酯成膜厚度较厚，浸水后聚氨酯级配碎石的抗压强度、抗折强度以及回弹模量基本保持不变；在长期动载作用下，聚氨酯级配碎石层累积变形、动压力以及动孔压在注水前后变化较小，有良好的力学行为和防水效果。

Study on Characteristics of Polyurethane Graded Gravel

For the water-induced damage of graded gravel layer under the coupling effect of high-speed train load and water, herein polyurethane graded gravel was taken to discuss with indoor model tests its long-term stress and the deformation law thereof under the coupling effect of water environment-dynamic loading. It is concluded as follows, when the content of polyurethane reaches 8 %, the porosity of polyurethane graded gravel reaches about 2 % and the polyurethane film is thick, thus after immersed in water, the compressive strength, bending strength and rebound modulus of polyurethane graded gravel remain the same basically; under the action of long-term dynamic loading, the cumulative deformation, dynamic pressure and dynamic pore pressure of polyurethane gravel layer change slightly before and after water injection. It is thus clear that polyurethane graded gravel layer has good mechanical behavior and waterproof effect.