土石路堤压实质量控制与碾压动力响应模拟分析

Compaction quality control and rolling dynamic response simulation analysis of earth-rock embankment

以国道丹阿公路省界(珲春)至东宁段改扩建工程为依托,选取具有代表性的土石混填路堤施工路段,研究得到不同松铺厚度、不同碾压遍数下土石路堤变形与压实特性,采用沉降差控制指标确定以强、中风化凝灰岩为主要填料的土石路堤压实现场施工工艺;同时采用便携式落锤弯沉仪(PFWD)对土石路堤动回弹模量E vd进行检测,将每遍碾压后土石路堤的E vd值与沉降差做线性拟合,拟合后的相关系数都在0.86以上,说明E vd值与沉降差有良好的线性相关性;并运用有限元理论建立土石路堤三维数值模型,进行振动荷载作用下路堤动力响应分析,分析了振动压路机对路基的压实效果及影响深度,发现竖向动应力沿深度方向衰减速度有先快后慢的趋势,32 t压路机振动压实过程可对下压实填层有反复补强压实作用,通过方差分析得到压路机振动频率因素对土石混填路堤振动压实影响的显著程度大于振幅激振力因素。

The representative earth-rock embankment construction section in the reconstruction and expansion project of the National Highway Dana Highway from the provincial boundary(Hunchun)to Dongning was selected to study the deformation and compaction characteristics of the earth-rock embankment under different loose paving thicknesses and different rolling cycles.In particular,the differential settlement control index was used to determine compaction construction technique of earth-rock embankment with main packing filler of highly-weathered and medium-weathered tuff.Portable falling weight deflectometer(PFWD)was used to detect dynamic elastic modulus(E vd)of earth-rock embankment.The E vd value and differential settlement of earth-rock embankment after each rolling are linearly fitted.All correlation coefficients are above 0.86,which indicates that the E vd value has a good linear correlation with the differential settlement.The finite element theory was used to establish a three-dimensional numerical model of the earth-rock embankment to analyze the dynamic response of the embankment under the action of vibration load.The compaction effect and influence depth of the vibratory roller on the roadbed was analyzed.It is found that the attenuation rate of the vertical dynamic stress along the depth direction tends to be initially fast and turns slow thereafter.The vibratory compaction process of a 32-ton roller can repeatedly strengthen and compact the lower compaction layer.Variance analysis indicates that the influence of roller vibration frequency on vibration compaction of earth-rock mixed embankment is greater than the amplitude excitation force.