循环动载下土工格栅加筋砾性土动力特性试验分析

为探究相同动应力比和相同动应力幅值下围压对加筋砾性土动力特性的影响,通过GDS动态三轴测试系统开展了土工格栅加筋砾性土动三轴试验。研究了相同动应力比和相同动应力幅值下围压对加筋砾性土轴向累积应变、回弹模量、动孔压的影响。结果表明:动应力比相同时,围压增大轴向累积应变随之增大,而动应力幅值相同时其规律恰恰相反;随围压的增大,回弹模量和动孔压均增大;相同动应力幅值时,回弹模量在振动初期的衰减较为明显,围压为120 kPa时衰减现象最为显著;随着围压的增大,动孔压均呈增大趋势,而孔压比基本维持在0.5左右,表明加筋砾性土具有良好的抗液化性能。

Experimental Analysis of Dynamic Characteristics of Geogrid Reinforced Gravel Soil under Cyclic Dynamic load

In order to explore the influence of confining pressure on the dynamic characteristics of reinforced gravel soil under the same dynamic stress ratio and the same dynamic stress amplitude, the geogrid reinforced gravel soil dynamic triaxial test was carried out by GDS dynamic triaxial test system. The effects of confining pressure on the axial cumulative strain, resilient modulus and dynamic pore pressure of reinforced gravel soil under the same dynamic stress ratio and the same dynamic stress amplitude are studied. The results show that when the dynamic stress ratio is the same, the axial cumulative strain increases with the increase of confining pressure, while the law of the dynamic stress amplitude is the opposite; with the increase of confining pressure, the resilient modulus and dynamic pore pressure are both When the amplitude of the same dynamic stress is used, the attenuation of the resilient modulus is evident at the initial stage of vibration. The attenuation phenomenon is most significant when the confining pressure is 120 kPa. With the increase of confining pressure, the dynamic pore pressure increases. The pore pressure ratio is basically maintained at about 0.5, and it can be seen that the reinforced gravel soil has good liquefaction resistance.