塔侧混凝土回填高度对长拦污栅墩进水塔的动力影响分析

Dynamic response of intake tower with long trash rack piers to the backfill height of side concrete

为了研究侧面混凝土回填高度对长拦污栅墩进水塔结构动力响应的影响规律,提高拦污栅框架结构的抗震性能,针对高耸进水塔结构建立不同塔侧回填高度的三维有限元模型进行动力计算,系统分析了侧面混凝土回填高度对进水塔自振特性、位移和应力的影响规律。结果表明:过高的塔侧回填会导致拦污栅墩部分连系梁的压应力超出混凝土抗压强度而发生断裂;无塔侧回填则会造成塔体横河向位移较大,同时连系梁的拉应力均比较大;合理的塔侧回填高度能够有效降低长拦污栅框架结构的应力,限制进水塔横河向位移,并且提高结构整体抗震性能。提出了长拦污栅墩进水塔侧面回填高度的合理范围,可供类似工程借鉴。

In order to improve the seismic performance of the trash rack structure,we studied the influence of the side concrete backfill height on the structure of the intake tower with long trash rack piers.A three-dimensional finite element model with different side backfill heights was established for the dynamic calculation of a tall intake tower,and the influence of the side concrete backfill height on the free vibration characteristics,displacement and stress of the intake tower were analyzed.Based on the calculation results,it is found that excessive backfill on the side of the tower adds extra compressive stress to some of the connecting beams of the trash rack piers exceeding their compressive strength,which will most likely result in beam fracture.On the other hand,the displacement of the tower across the river and the tensile stress of the connecting beams becomes larger without backfill on the side.An appropriate backfill height on the side can effectively reduce the stress of the long trash rack structure,limit the displacement across the river,and improve the overall seismic performance of the structure.The advisable range of the side backfill height of the intake tower with long trash rack piers proposed in this paper can be used as references for similar projects.