土石混合路基填料动回弹模量试验研究

Experimental Study on Resilient Modulus of Soil-Rock Mixture

采用美国国家公路与运输协会标准路基土和混合集料试验方法(AASHTO:T307—99(2012)),通过循环动荷载三轴试验,得到两种岩石骨料(块状花岗岩和微风化片状石灰岩)、不同土石含量(RBP)以及饱和与烘干状态下土石混合体的动态回弹模量。研究表明:不同含石量的土石混合料Mr随着应力水平变化表现出不完全一致的规律;低围压下Mr值随着偏应力峰值增加有明显降低趋势;高围压、高含石量下的Mr值随着偏应力峰值增加具有明显增加趋势,并且骨料为花岗岩的试样和烘干试样的Mr相对较高,与此同时,随着含石量的增加,Mr平均值亦有所增加。

In accordance with American national highway and transportation association（ AASHTO： T307-99（ 2012） 1）,cyclic load triaxial test was carried out to get resilient modulus（ Mr） on samples which is the massive granite or flake limestone in different rock block proportion（ RBP）,saturated or dry state. On one hand,as RBP changes,the aggregate shows different laws with the dynamic stress level. Under low confining pressure,Mrdecreases as stress improve; on the contrary,Mrincrease as the maximum deviatoric stress improve when the test is under high confining pressure and high RBP. Besides test on the massive granite and drying samples shows higher Mr; on the other hand,the average Mradds with higher RBP.