研究目的:基于山东东营某重载铁路路基工程,以重载铁路路基为研究对象,通过一系列循环振动三轴试验,探究在氯盐侵蚀和循环振动荷载双重因素耦合作用下重载铁路路基的累积动应变发展变化规律,进一步揭示路基土体变形影响因素及其规律.研究结论:(1)循环振动荷载作用下,土体累积动应变随着循环振动次数的增加而不断增大;(2)不同的动应力比下,累积变形曲线呈现出稳定型、临界型和破坏型三种类型;(3)干密度越大,土体抵抗变形的能力越强,累积动应变发展速率越小,临界动应力比越大;(4)土体的累积动应变发展速率随含水率、含盐量和振动频率的增大而不断加快;(5)围压和含水率均可以改变土体累积动应变的发展类型,随着围压的增加,路基的变形速率降低;(6)该研究成果可为重载铁路路基设计与施工提供参考.%Research purposes:Based on a heavy-load railway subgrade project in Dongying,Shandong Province,this paper takes the heavy load railway subgrade as the research object,explores the accumulation dynamic strain development and change law of heavy haul railway subgrade under the coupling of chloride salt erosion and cyclic vibration load through a series of cyclic vibration triaxial tests,and further reveals the influencing factors and laws of subgrade soil deformation.Research conclusions:(1) Under the cyclic vibration load,the cumulative dynamic strain of the subgrade soil increases with the increase of the number of cyclic vibration.(2) Under different dynamic stress ratios,the cumulative deformation curve shows three types:stable,critical and destructive.(3) The greater the dry density,the stronger the soil resistance to deformation,the smaller the cumulative dynamic strain development rate,the greater the critical dynamic stress ratio.(4) The cumulative dynamic strain development rate of soil is accelerating with the increase of the moisture content,salt content and vibration frequency.(5) Both confining pressure and water content can change the development type of accumulated dynamic strain of soil mass.As the confining pressure increases,the deformation rate of subgrade decreases.(6) The research results can provide reference for the design and construction of heavy load railway subgrade.
展开▼
