冲击碾压改建旧水泥混凝土路面施工时的地基振动特性

为了解冲击碾压水泥混凝土路面施工时的地基振动与影响特性，基于动力三维有限元分析方法，考虑材料的弹塑性，对四楞冲击压路机冲击碾压水泥混凝土路面时地基的振动与传播特性进行了研究，并将数值计算结果与现场地基振动监测数据进行了对比分析；然后将冲击碾压地基实测振动信号作为输入，对离震源不同距离的砌体和框架建筑结构时程动力响应进行了计算，探讨了冲击碾压改建施工的安全防护标准。研究表明冲击碾压引起的地基振动具有冲击瞬态特性，地基振动中竖向振动加速度分量最大，横向振动和纵向振动加速度大小相当。振动加速度各分量沿道路横向距离10m范围内衰减变化显著，随着冲击破碎遍数递增，土基振动有增大现象。冲压振动与结构物的共振效应较小，对15m以外的完好建筑物影响很小。建议在普查无临界状态房屋条件下结构安全距离为15m，考虑对人的振动影响安全距离为20m。

Subgrade vibration characteristics during PCC pavement rehabilitation with impact roller

Subgrade vibration characteristics during concrete pavement rehabilitation with impact roller were studied by three dimensional elastic-plastic dynamic FEM,and the calculation results were verified by feild test data.Based on the results of field monitoring data,the dynamic time history response of different buidings under subgrade vibration and construction safety distance were analyzed. The results indicate that subgrade vibration induced by impact rolling load has impact transient property, and subgrade vertical vibration acceleration is maximum between vertical,longitudinal and transverse vibration acceleration. vibration acceleration decaies significantly in the range of 10m away from the compaction source.and vibration acceleration increases a little with impact times increase. Subgrade vibration has little dynamic effect on buildings which is 15m far away from the compaction source ,and buildings resonance effet is little. It is advised the safety distance is 15m far away from the compaction source for the buildng in good condition,and safety distance is 20m for considering human feeling.