振动压实是高速公路路基压实施工的重要工程工法之一,可以快速有效地提高路基材料的强度和整体稳定性,同时基于振动压实的连续压实控制技术为路基压实质量的检测与管控提供了新的技术手段.为探究路基振动压实过程中的振动轮响应特征,以及常用的谐波比类压实质量实时评价指标在不同压实阶段的适用性,通过对振动轮-路基系统进行作用分析,分别构建了接触与脱空两种工况下的动力学模型,通过引入阶跃函数δ(Fc)实现两种工况下动力学方程的统一构建,并利用Simulink对该动力学方程进行仿真,基于仿真结果对振动压实响应特征和指标适用性进行分析.研究结果表明:路基压实过程可根据振动轮-土体接触力变化周期Tc与激振周期T0的比较分为Tc=0、Tc=T0、Tc=2T0、Tc＞2T0 4个阶段,在Tc=T0阶段会出现整数倍的谐波信号且谐波幅值会随着土体刚度增加而增大,在Tc=2T0阶段会出现0.5倍次谐波信号;CCV(compaction control value)、THD(total harmonic distortion)指标相较于 CMV(compaction meter value)指标在压实全过程具有更好的适用性,RMV(resonance meter value)指标能够精准反映出压实过程达到阶段三(Tc=2T0).
Response Characteristics Analysis and Indicator Applicability of Subgrade Vibration Compaction
Vibratory compaction stands as a crucial engineering technique in highway subgrade compaction works,rapidly and effectively enhancing the strength and overall stability of the subgrade materials.Additionally,the continuous compaction control technology based on vibratory compaction offers novel technical means for monitoring and managing the quality of subgrade compaction.To investigate the vibratory roller response characteristics during the compaction process and the suitability of commonly used harmonic ratio-based compaction quality real-time evaluation indicators at different compaction stages,the interaction between the vibratory roller and the subgrade system was analyzed in this study.The dynamic models for the contact and detachment conditions were established respectively,and the step function δ(Fc)was used to unify the dynamic equations for both scenarios.Simulink was utilized to simulate these dynamic equations,and the simulation results were analyzed to assess the response characteristics of vibratory compaction and the applicability of indicators.It is indicated that the subgrade compaction process can be divided into four stages by comparing the variation cycle Tc of the contact force between the vibratory roller and the soil with the excitation period T0:Tc=0,Tc=T0,Tc=2T0 and Tc＞2T0.During the Tc=0 stage,integer multiples of harmonic signals are observed,and the amplitude of these harmonics increases with the stiffness of the soil.At the Tc=2T0 stage,signals of 0.5 times the harmonic are observed..Comparative analysis reveals that the CCV(compaction control value)and THD(total harmonic distortion)indicators exhibit better applicability throughout the entire compaction process compared to the CMV(compaction meter value)indicator.Furthermore,the RMV(resonance meter value)indicator accurately reflects the compaction process reaching stage three(Tc=2T0).
万方数据
维普
