不同频率循环荷载下公路路基粗粒填料长期动力特性试验研究

发布时间：2018-06-25 15:36

本文选题：土力学 + 粗粒土　；参考：《岩石力学与工程学报》2017年05期

【摘要】：交通荷载作用频率随着车辆运行速度等因素变化而变化,目前对不同频率荷载下路基长期性能还缺乏一致性认识。为揭示不同频率荷载下路基粗粒土填料长期动力特性,利用GDS大型三轴试验系统对路基填料进行饱和排水循环荷载试验,分析不同应力路径下荷载频率对路基粗粒填料长期动力特性影响规律。试验结果表明,荷载频率增加使路基填料在密实阶段产生更大累积体缩应变而更密实,进而路基动力回弹模量随荷载频率增加显著增加。路基填料轴向累积变形在不同频率循环荷载下也呈现不同发展规律,路基填料密实阶段轴向累积变形在高循环应力比(ζ=3,5)下随荷载频率增加显著增大,但在低循环应力比(ζ=1)下,荷载频率对轴向累积变形影响较小;当填料进入变形稳定阶段,荷载频率对轴向累积变形基本无影响。该研究揭示了路基填料层在不同频率荷载下长期动力特性,发现降低路基中循环应力比,可大大减小荷载频率对路基长期动力特性影响,本研究可为准确预测和控制道路工后沉降提供参考。
[Abstract]:The frequency of traffic load varies with the change of vehicle speed and so on. At present, the long-term performance of roadbed under different frequency loads is still lack of consistent understanding. In order to reveal the long-term dynamic characteristics of roadbed coarse grained soil fillers under different frequency loads, the saturated drainage cyclic load test of roadbed fillers was carried out by using GDS large triaxial test system. The effect of load frequency on the long-term dynamic characteristics of roadbed coarse grain filler under different stress paths is analyzed. The experimental results show that the increasing of load frequency makes the subgrade filler produce more accumulated shrinkage strain and compactness, and the dynamic elastic modulus of subgrade increases significantly with the increase of load frequency. The axial cumulative deformation of subgrade filler also presents different development laws under different frequency cyclic loads. The axial cumulative deformation increases significantly with the increase of loading frequency at high cyclic stress ratio (味 ~ (3) ~ (5), but at a low cyclic stress ratio (味 ~ (1). The load frequency has little effect on the axial cumulative deformation, but the loading frequency has no effect on the axial cumulative deformation when the filler enters the stage of deformation stabilization. This study reveals the long-term dynamic characteristics of subgrade filler under different frequency loads. It is found that reducing the cyclic stress ratio in subgrade can greatly reduce the influence of load frequency on the long-term dynamic characteristics of roadbed. This study can provide a reference for accurate prediction and control of road settlement after construction.
【作者单位】：浙江大学滨海和城市岩土工程研究中心;温州大学建筑工程学院;温州大学浙江省软弱土地基与海涂围垦工程技术重点实验室;
【基金】：国家重点研发计划(2016YFC0800204) 国家自然科学基金资助(51578500,51578426)~~
【分类号】：U416.1

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