路用红砂岩粗粒土的流变特性试验研究

为了研究红砂岩粗粒土高速公路路堤填料的流变工程性质,利用大型三轴流变试验仪对路用的90区和93区红砂岩粗粒土进行低应力状态(σ3=100,200和300 kPa)的三轴流变试验,研究红砂岩粗粒土在低应力下的流变规律以及应力状态对体积流变分量和剪切流变分量的影响。引入Morgan-Mercer-Florin核函数,建立描述红砂岩粗粒土的体积流变分量-时间的关系和剪切流变分量-时间关系模型,提出红砂岩粗粒土最终体积流变量和最终剪切流变量公式。最后,建立一个基于Morgan-Mercer-Florin函数新的红砂岩粗粒土流变本构模型,确定压实度为90％和93％的红砂岩粗粒土的流变模型参数,并将Morgan-Mercer-Florin模型嵌入椭圆-抛物线双屈服面弹塑性本构模型,用于描述红砂岩粗粒土的粘弹塑性性质。流变试验结果表明:球应力(p)对最终体积流变分量影响很大,应力水平(S)对最终剪切流变分量影响显著,最终体积流变量和最终剪切流变分量可以分别用p和S表示。

Test study of red stone granular soil's rheological property in road embankment engineering

To study the rheological properties of red stone granular soil in the high way earth-stone filled embankment engineering,the red stone granular soil's rheological tests were carried out in the large triaxial apparatus under low confining stress conditions,including 100,200 and 300 kPa.Through these rheological tests,the rheological properties, and the main factors affecting the red stone granular soil's rheological properties were analyzed.The rheological properties of the red stone granular soil,the stress conditions effects on the final volume rheological strain value and final shear rheological strain value of redstone granular soil were studied.At the same time,the final volume rheological strain value and the final shear rheological strain value could be formulated by p and S,respectively.According to the rheological tests results,creep curves of red stone granular soil show the non-linear rheological properties and the Morgan-Mercer-Florin function was used to describe the non-linear rheological properties.The Morgan-Mercer-Florin function was used to set up a new rheological function model to describe the non-linear rheological properties of red stone granular soil in rheological tests.Two new functions were set up to calculate the red stone granular soil's final volume rheological strain value and final shear strain value by p and S. At last, a new red stone granular soil's rheological constitutive model based on Morgan-Mercer-Florin function was presented,and the parameters of this rheological constitutive model were identified by the triaxial rheological tests' data of red stone granular soil with 90% and 93% relative compactness.This new rheological model was put into the double surface elastoplastic yield model to describe the redstone granular soil's viscous elastoplastic stress-strain relationship.The tests' results show that the stress conditions are the main factors affecting the rheological properties,the spherical stress (p) has direct effect on the final volume rheological strain value and the stress level (S) has direct effect on the final shear rheological strain value.