液压夯补强路基动力响应现场试验研究  

In-situ Experimental Study on Dynamic Response of Subgrade Reinforced by Hydraulic Impactor

作　　者：李晋[1] 姜鹏[2] 李天宇 常德 崔新壮 LI Jin;JIANG Peng;LI Tian-yu;CHANG De;CUI Xin-zhuang(Shandong Jiaotong University,Jinan Shandong 250357,China;School of Civil Engineering,Shandong University,Jinan Shandong 250061,China;Jinan Jinyue Highway Engineering Co.,Ltd.,Jinan Shandong 250101,China)

机构地区：[1]山东交通学院,山东济南250357 [2]山东大学土建与水利学院,山东济南250061 [3]济南金曰公路工程有限公司,山东济南250101

出　　处：《公路交通科技》2022年第9期67-74,共8页Journal of Highway and Transportation Research and Development

基　　金：国家重大科研仪器研制项目(52027813);山东省交通运输厅科技计划项目(2019B03,2020B03)。

摘　　要：路基弱碾区及碾压盲区的压实补强施工常常采用液压夯进行作业,能够实现良好的压实效果。为了探究液压夯冲击作用下一般性粉质黏土回填路基的动力响应特征,伴随路基正常施工周期埋设动态土压力盒,动态加速度计等传感器,采用不同量级的液压夯开展了现场原位试验,以期揭示一般性粉质黏土土体应力时空响应规律与加速度响应规律。结果表明:土体中动应力竖直方向传播时,夯击能越大损耗越小,夯点正下方0.5 m深度处,水平方向上应力衰减幅度先小后大,夯点正下方1.0 m深度处的水平方向上,随距离增大衰减幅度增大;路基表层土体惯性使应力波产生第2个波峰,路基深层土体处,动力夯实作用下表现为弹性振动特征;冲击能越大,同一深度处应力波作用周期越长,应力波传递到夯点以下同一深度处土体加速度响应衰减幅度越小;在将机械-土体相互作用视为非完全弹性碰撞的基础上,取恢复系数k为0.8,参振土体为最佳含水率下的一般粉质黏土土质,参振土体体积取底面与锤体底面积一致、高为锤体行程的1.72倍的圆柱体,由此所提出的液压夯补强粉质黏土路基的动应力解析与实测值相符程度较高。Hydraulic impactor is often used in the compaction and reinforcement construction in subgrade weak rolling area and blind rolling area, which can achieve good compaction effect. In order to explore the dynamic response characteristics of common silty clay backfill subgrade under the impaction of hydraulic impactor, the sensors such as dynamic earth pressure boxes and dynamic accelerometers are buried with the normal subgrade construction period, the in-situ test is carried out by using hydraulic impactors of different magnitudes to reveal the temporal and spatial response rules of stress and acceleration of general silty clay soil. The result shows that(1) When the dynamic stress in the soil propagates in the vertical direction, the larger the compacting energy, the smaller the loss. At a depth of 0.5 m directly below the compacting point, the stress attenuation amplitude in the horizontal direction decreased first and then increased, while at the depth of 1.0 m directly below the compacting point, the attenuation amplitude increases with the increase of horizontal distance.(2) The inertia of the surface soil of the subgrade caused the second peak of the stress wave, and the deep soil of the subgrade shows the elastic vibration characteristics under the action of dynamic compaction.(3) The larger the impact energy, the longer the action period of the stress wave at the same depth, and the smaller the attenuation amplitude of the acceleration response of the soil at the same depth below the compacting point.(4) On the basis of treating the mechanical-soil interaction as an incompletely elastic collision, taking the recovery coefficient k as 0.8, the vibrating soil is common silty clay with the best moisture content, and taking The volume of vibrating soil as a cylinder whose bottom surface is consistent with the bottom area of the hammer body and the height is 1.72 times the stroke of the hammer body, therefore, the proposed dynamic stress analysis values hydraulic compaction reinforced silty clay subgrade is in g

关 键 词：道路工程 动力响应 现场试验 液压夯 粉质黏土 

分 类 号：U416[交通运输工程—道路与铁道工程]