聚氨酯高聚物材料应用于被动隔振的试验研究与理论分析

This project is positioning vibration isolation which is one of current hot environment vibration problems, the piles and walls made of polyurethane polymer materials are introduced to the passive vibration isolation, the polymer materials are succeeding in the weak foundation reinforcement and soil dam seepage, and experiment, theoretical analysis and numerical simulation are used to study the problem of vibration isolation. Frequency adjustable polymer and vibration test system are established, different thickness and density requirements of polymer plate are made by way of orthogonal test preparation, and polymer and vibration performance would be determined. Open fields far away from vibration are selected, empty ditch, multiple rows of polymer piles, multi-channel polymer walls and polymer structure of vibration isolation test WIB are made in the fields, different tonnage impact loads and different frequency of heavy traffic loads are manufactured, a barrier of the acceleration tests are set up before and after the barriers, and isolation effect evaluation index of all kinds of barriers would be put forward. The polymer and vibration performance are introduced as parameters to potential function expansion of wave fields, the test results are considered, and calculation formula of passive isolation mechanism about the polymer barrier would be established based on elastic wave propagation and multiple scattering theory. The passive isolation mechanism of polymer barrier is numerically simulated by BEM and FEM, and the isolation effect influenced by vibration frequency, soil damping, polymer density and other factors are analyzed. In the end, the isolation mechanism of polymer barrier and numerical solutions would be spread from elastic soils to saturated soils.

本项目定位于隔振这一当前比较热门的环境振动问题，将应用于软弱地基加固的高聚物桩和土质堤坝防渗的高聚物墙引入到被动隔振，拟采用现场试验、理论分析和数值模拟相结合的方式研究其隔振机理。建立频率可调高聚物吸振测试系统，按照正交试验制备不同厚度和密度的高聚物板，测定高聚物的吸振性能；选取远离振动干扰的空旷区域进行空沟、多排高聚物桩、多道高聚物墙和高聚物WIB结构的隔振试验，人工制造不同吨位的冲击荷载和不同频率的重交通荷载，测试屏障前后的加速度场，提出各类屏障隔振效果的评价指标；以黏弹性参数表征高聚物材料的吸振性能，并引入到波场的势函数展开式中，基于弹性波的传播和多重散射理论，以现场试验结果为基准，建立高聚物屏障被动隔振的计算公式；采用BEM和FEM进行高聚物屏障隔振的数值模拟，分析振动频率、土体阻尼、高聚物密度等因素对隔振效果的影响；最后，将高聚物屏障隔振的相关研究成果由弹性土体推广到饱和土体。

采用现场试验、理论分析和数值模拟相合的方式研究了聚氨酯高聚物材料隔振机理和隔振效果，并与常规隔振措施（空沟、混凝土排桩）进行了对比分析。采用压电陶瓷弯曲元测试系统对不同密度高聚物材料的动剪切模量进行了室内试验测定，得到了动剪切模量与密度的经验公式。选取远离振动干扰的空旷区域作为试验场地，建立了空沟、高聚物空心墙、高聚物实心墙、高聚物排桩、混凝土排桩等隔振措施，在屏障后布置三向加速度传感器，采用FWD制造不同吨位的冲击荷载，测试了屏障后的加速度场，对比了上述各种措施的隔振效果；运用复变函数的保角映射方法和波场的势函数展开法建立了高聚物排桩和混凝土排桩对振动波隔离的理论解答，并以现场试验结果为校核基准，运用有限元软件ABAQUS从数值上模拟了高聚物排桩和混凝土排桩的三维隔振机理，基于理论分析和数值模拟着重分析了高聚物排桩和混凝土排桩的间距、深度和振动波频率、桩土模量比（即刚度比）等参数对隔振效果的影响；提出高聚物WIB结构（蜂窝结构）的隔振措施，运用复变函数的保角映射方法和波场的势函数展开法建立了高聚物WIB结构对振动波隔离的理论解答，并与多排柱腔列的隔振效果进行了对比分析，前者的隔振效果好于后者。上述现场试验、理论分析和数值模拟的研究结果表明：空沟、高聚物空心墙、高聚物WIB结构的隔振效果最好，适合于土层较好的场地（土质较硬、地下水埋藏深）和浅振源，但空沟侧壁土坡直立性能不好，不能作为长期的隔振措施，而高聚物空心墙、高聚物WIB结构自身能支护土坡，可以作为长期的隔振措施；高聚物实心墙、高聚物排桩、混凝土排桩的隔振效果较为理想，不受场地土层的限制，可以作为长期的隔振措施，相对于混凝土排桩，高聚物实心墙、高聚物排桩的施工周期短，高聚物材料具有一定的吸振作用，隔振效果好于混凝土排桩，因此更有应用前景。高聚物材料隔振研究成果已经应用于某钧官窑遗址对重交通振动和某轴承加工平台对相邻车间振动的隔离，均达到隔振设计要求。