基于颗粒离散元方法的膨胀土路基破坏特征研究

Research on Failure Characteristics of Expansive Soil Roadbed Based on Particle Discrete Element Method

路基施工过程中,难免遇到受灾害性膨胀土影响的工程问题。为了探究膨胀土路基在胀缩循环作用下的细观破坏特征,文章利用颗粒离散元方法进行了土体膨胀率测试,通过膨胀土路基胀缩作用过程模拟,分析了胀缩循环次数对路基破坏特征的影响。结果表明:(1)膨胀土路基内部裂隙发育与边坡坡向有关;(2)膨胀土胀缩循环次数对路基稳定性和裂隙发育程度影响显著,胀缩循环发生次数越多,坡体越易发生拉裂破坏。

During the roadbed construction,it is inevitable to encounter engineering problems affected by catastrophic expansive soil.In order to explore the microscopic failure characteristics of expansive soil subgrade under the action of expansion and contraction cycles,this article uses the particle discrete element method to test the soil expansion rate.Through the simulation of the expansion and contraction process of expansive soil subgrade,the influence of the number of expansion and contraction cycles on the failure characteristics of subgrade is analyzed.The results indicate that:(1)the development of internal cracks in expansive soil subgrade is related to the slope direction of the slope;(2)The number of cycles of expansion and contraction of expansive soil has a significant impact on the stability of the roadbed and the degree of crack development.The more cycles of expansion and contraction occur,the more likely the slope is to undergo tensile cracking and failure.