MHB碎石化动力响应及其对邻近建筑和居民的振动影响

MHB碎石化技术广泛应用于改建工程中旧水泥混凝土路面破碎,但冲击破碎过程中对邻近建筑和居民的振动影响问题亟待解决.基于弹性理论和波动理论对冲击荷载下路面板的物理参数衰减规律进行推导分析;依托山东S245省道旧水泥混凝土路面改建工程现场振动监测试验,并结合ANSYS/LS-DYNA动力有限元数值模拟对不同影响因素下路面板的三向动力响应进行研究,探寻碎石化邻近建筑物水平安全距离和影响居民舒适度的临界距离.结果表明:MHB碎石化施工振动属于冲击型振源,振动以负幂指数形式衰减,且计算、实测和数值模拟结果曲线衰减趋势一致;随着冲程的增大,碎石化动力荷载峰值出现时间不断提前;振动速度峰值1cm/s可作为判断邻近建筑安全与否的控制指标;当重锤下落高度分别为0.8m、1.0m、1.2m时,临近建筑物水平安全距离分别为14m、18m、20m,影响居民舒适度的临界距离分别为24m、29m、和31m.

Dynamic Responses and Influence on the Vibration of the Adjacent Buildings and Residents of MHB Rubblization

MHB rubblization technology is widely used in the reconstruction of the old cement concrete pavement (PCC) crushing, however, the impact of vibration on the adjacent buildings and residents during the impact crushing process needs to be urgently resolved. The attenuation law of physical parameters of the pavement panel under impact load were deduced and analyzed based on elastic theory and wave theory. Relying on the field vibration monitoring test on the old PCC pavement reconstruction project of Shandong provincial highway S245, and combing with ANSYS/LS-DYNA dynamic finite element numerical simulation, the three-dimensional dynamic response under different influence factors was studied. Then, the level safety distance of rubblization adjacent buildings and the comfortability critical distance of the residents were explored. The results show that MHB rubblization belongs to impact type vibration source, whose vibration is a negative exponential curve in the form of a sharp attenuation, and the results of calculation, measurement and numerical simulation are in agreement with the attenuation trend of the curve. With increasing stroke the peak time load continuously advances. The peak vibration velocity of 1cm/s can be used as a control index for judging the safety of adjacent building. When the hammer drop height is 0.8 m, 1.0 m, 1.2 m respectively, the level safety distance of adjacent building is 14 m, 18 m, 20 m respectively, and the comfortability critical distance of inhabitants is 24 m, 29 m, 31 m respectively.