单一粒径组碎石道砟颗粒破碎规律试验研究

Experimental Study on Law of Particle Breakage for Uniform Ballast

道砟颗粒破碎会影响路基的力学行为和服役性能。为定量分析颗粒形状、粒径、冲击荷载三者对碎石颗粒破碎的影响,选用单一粒径组安山岩碎石道砟颗粒,进行颗粒破碎试验研究。研究结果表明:颗粒破碎比B g可用于定量分析道砟的颗粒破碎规律;道砟形状是控制其破碎的主要因素,片状颗粒和针状颗粒在试验中的平均质量损失率高达40%;而块状颗粒的破碎主要以磨损为主,质量损失率低于4%;颗粒破碎指标B g和冲击荷载能量存在良好的线性关系;颗粒破碎过程可以划分为空间调整、接触破碎及平衡稳定三个阶段。

The breakage of ballast particles will affect the mechanical behavior and service performance of subgrade.In order to quantitatively evaluate the influence of particle shape,particle size and impact load on particle breakage,a particle breakage test was conducted on ballast with uniform particles.The results demonstrate that the breakage ratio B g is a good indicator for the evaluation of particle breakage.Ballast shape is the main factor that influences ballast particle breakage.The average mass loss rate of flake and acicular particles in the test is up to 40%.However,the mass loss rate of regular particles is less than 4%.There is a good linear relationship between the particle breakage index B g and impact load energy.The process of particle breakage can be divided into three stages including space adjustment,contact breakage and balanced stability.