摘要
采用室内试验方法,在水泥+粉煤灰改良膨胀土基础上,掺入不同量的玄武岩纤维或天然砂对其进行进一步的改良,重点研究改良膨胀土在冲击荷载作用下的动态力学特性。研究结果表明:冲击荷载作用下,改良膨胀土应力—应变曲线分为弹性变形、塑性屈服硬化以及破坏变形三个阶段;当玄武岩纤维掺量为0.6%或者天然砂掺量为8%时,改良膨胀土的动态力学性能最佳;掺入玄武岩纤维的改良膨胀土,其冲击破碎分形维数随掺量的增大而呈线性减小,掺入天然砂的改良膨胀土,其冲击破碎分形维数随掺量的增大而逐渐增大;玄武岩纤维对水泥+粉煤灰膨胀土路基动态特性的改良效果要略优于天然砂的改良效果。
based on the expansive soil improved by using cement+fly ash,the basalt fiber or natural sand are further added to the improved expansive soil.The dynamic mechanical characteristics of the improved expansive soil under impact loads are mainly studied.The study results show that the stressstrain curve of the improved expansive soil is divided into the three stages that is the elastic deformation,the plastic yield hard and the failure deformation under impact loads.When the content of basalt fiber is0.6%or the content of natural sand is 8%,the dynamic mechanical properties of the improved expansive soil are the best.The impact fracture fractal dimension of the improved expansive soil with the basalt fiber decreases linearly with the increase of the content of the fiber,and the impact fracture fractal dimension of the improved expansive soil with the addition of natural sand increases with the increase of the content of the sand gradually.The improvement effect of dynamic characteristics for the expansive soil subgrade improved by using cement+fly ash with basalt fiber is slightly better than that with natural sand.
机构地区
河南省交通规划设计研究院股份有限公司
出处
《工程勘察》
2021年第5期25-30,共6页
Geotechnical Investigation & Surveying
关键词
路基工程
玄武岩纤维
天然砂
水泥+粉煤灰改良膨胀土
掺量
动态力学特性
破碎分形维数
subgrade engineering
basalt fiber
natural sand
expansive soil improved by cement+fly ash
mixing content
dynamic mechanical property
fracture fractal dimension
