红砂岩路基土动态模量影响因素及预估模型研究

为研究红砂岩路基土动态模量的影响因素,采用室内重复加载三轴试验。结合红砂岩路基土在不同含水率时的动态模量,分析偏应力、体应力和含水率对红砂岩路基土动态模量的影响;采用三参数复合模型进行回归,并通过有限元计算和实体工程现场检测,建立室内试验动态模量与现场检测动态模量的回归关系。研究结果表明,动态模量随体应力(或围压)增大而增大,随偏应力增大而减小;随着含水率的增大,动态模量呈先增大后逐步减少的趋势。三参数复合预估模型与试验检测结果之间具有较高相关性。此外,红砂岩路基土室内试验动态模量与现场检测动态模量具有良好的回归关系,室内试验动态模量与现场检测动态模量可以实现有效换算。

On the Influence Factors of Dynamic Modulus and Prediction Model of Red Sandstone Subgrade

To understand the influencing factors of dynamic modulus of red sandstone subgrade, a repeated loading triaxial test in laboratory was carried out. The effect of deviatoric stress, body stress and moisture content on the dynamic modulus of red sandstone subgrade soil was analyzed, by taking account the moisture content variation. Three-parameter composite regression model was adopted. Based on the results of finite element calculation and on-site tests, the regression relation between indoor dynamic modulus and on-site dynamic modulus was established. Results indicate that the dynamic modulus increases with the increasing body stress and decreases with the increasing deviatroric stress. The effect of moisture content on dynamic modulus is also very significant. It first increases and then gradually decreases with the increasing moisture content. There is a high correlation between three-parameter composite model and test results. Furthermore, there is a good regression relation between indoor dynamic modulus and on-site dynamic modulus. Both moduli can be converted mutually and effectively.