季冻区路基土静动模量关系研究

Study on Relationship Static and Dynamic Moduli of Subgrade Soil in Seasonal Frozen Area

为了分析路基土动弹性模量和静弹性模量的相关性,针对3种不同塑性指数的季冻区路基土,在最佳含水量状态下制成压实度大于95%的试件,在不同围压条件下进行了静、动三轴试验,得出了经历不同冻融循环次数的路基土静、动弹性模量,分析了围压、冻融循环次数对静、动弹性模量的影响规律;基于统计方法,建立了采用静弹性模量推导其动弹性模量的数学表达式。结果表明:随着围压和塑性指数的增大,试件的静、动弹性模量逐渐增大,随着冻融循环次数的增加,其静、动弹性模量逐渐下降最后基本趋于稳定;季冻区路基土静弹性模量与动弹性模量之间具有良好的相关性。研究结果说明了季冻区路基土的静、动弹性模量并没有本质区别,只是在不同加载条件下的力学性质表现。

In order to analyze the correlation between subgrade soil dynamic elastic modulus and static elastic modulus, three different plasticity indexed subgrade soils in seasonally frozen area are compacted under optimum moisture content to specimens with compactness greater than 95%. The static triaxial and dynamic triaxial tests are carried out under different confining pressures, and the static and dynamic elastic moduli of subgrade soil experienced different freeze-thaw cycles are obtained. The variation of static and dynamic elastic modul with confining pressureand freeze-thaw cycles is obtained. Based on statistical methods, the mathematical expressions of deriving dynamic elastic modulus using static elasticity modulus is established. The results show that （ 1 ） the static and dynamic elastic moduli of specimens increased gradually with the increase the confining pressure and plasticity index, the static and dynamic elastic moduli decreased and last basically stabilized with the increase of freeze-thaw cycles; （2） the static elastic modulus and dynamic elastic modulus of subgrade soil in seasonally frozen area modulus and it is only the dynamic elastic modulus of subgrade have a good correlation. The study shows that static elastic soil in seasonally frozen area are of no essential difference, different performances in mechanical properties under different loading conditions.