循环荷载作用的加筋砾性土三轴试验动力特性分析

Analysis of dynamic characteristics of reinforced gravel soil in triaxial test under cyclic loading

为了探究加筋前后饱和砾性土动力特性的变化规律,开展一系列循环荷载下饱和砾性土动三轴试验,分析不同围压下加筋对饱和砾性土轴向累积应变、回弹模量和动孔压等动力特性的影响,并对不同围压下的轴向累积应变与振次关系进行拟合分析。结果表明:随着围压的增大,加筋前后试样轴向累积应变、回弹模量及动孔压均随之增大;与加筋前相比,加筋后的试样轴向累积应变均有减小,而回弹模量和动孔压均有增大;各工况下动孔压与振次关系曲线均呈稳定型增长模式。提出了可以准确描述不同围压下加筋前后砾性土轴向累积应变与振次关系的函数关系式,通过函数关系式和条件参数可为预测加筋砾性土路基在循环荷载作用下的累积沉降提供参考。

In order to investigate the variation law of dynamic characteristics of saturated gravel soil before and after reinforcement,a series of saturated triaxial tests of saturated gravel soil under cyclic loading were carried out.The effects of reinforcement under different confining pressures on dynamic characteristics of axial cumulative strain,rebound modulus and dynamic pore pressure of saturated gravel soil were compared and analyzed.The relationship between axial cumulative strain and vibration amplitude under different confining pressures was fitted.The results show that with the increase of confining pressure,the axial cumulative strain,elastic modulus and dynamic pore pressure of the sample before and after reinforcement increase.Compared with that before reinforcement,the axial cumulative strain of the sample after reinforced is reduced,while the rebound modulus and dynamic pore pressure are increased.The relationship between the dynamic pore pressure and the vibration time in each working condition shows a stable growth pattern.A functional relationship that can accurately describe the axial cumulative strain and vibration times of gravel soil before and after reinforcement under different confining pressures is proposed.The functional relationship and parameters can be used to provide a reference for predicting the cumulative settlement of reinforced gravel soil subgrade under cyclic loading.