大体积混凝土底板微振动控制能力的测试与分析  

Test and analysis on the micro-vibration control ability of mass concrete slab

作　　者：荣慕宁 顾雅彬 郑明 聂鑫[2] 樊健生[2] 刘宇飞 RONG Muning;GU Yabin;ZHENG Ming;NIE Xin;FAN Jiansheng;LIU Yufei(Beijing Construction Engineering Group Co.,Ltd.,Beijing 100055,China;School of Civil Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]北京建工集团有限责任公司,北京100055 [2]清华大学土木水利学院,北京100084

出　　处：《地震工程与工程振动》2024年第4期115-124,共10页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金杰出青年基金项目(52325802)。

摘　　要：为测试北京光源这一精密科学设施中大体积混凝土底板的微振动控制能力,通过在建设现场进行短期测试和24 h长期监测的方式对底板微振动水平和微振动控制能力进行了评估。结果表明:在2次短期测试过程中,底板表面微振动位移有效值主要分布在10~50 nm之间,而在24 h监测过程中,底板表面微振动位移有效值主要在分布20 nm以下;大体积混凝土底板对10 Hz以上垂直于地面方向的微振动及5 Hz以上水平向的微振动体现出较好的控制作用;大体积混凝土底板最大能够将垂直地面方向微振动水平降低24%,水平向微振动水平降低34%,底板对水平向微振动控制能力略优于对竖向微振动的控制能力。建立了二维简化有限元模型,讨论了改变混凝土层密度、刚度及厚度对底板微振动控制能力的影响,模拟结果表明在现有激励条件下,增大底板配筋层厚度或素混凝土层密度对底板竖向微振动控制能力无明显影响,但对水平向微振动控制能力产生不利影响。In order to test the micro-vibration control ability of the mass concrete slab in the Beijing High Energy Photo Source,evaluation of the micro-vibration control ability of the mass concrete slab are conducted through two short-period tests and a 24 h long-period monitoring.Test results indicate that:most of the displacement root mean square values distribute between 10 nm and 50 nm in the two short-period tests,and most of the displacement root mean square values distribute below 20 nm in the 24 h long-period monitoring.The mass concrete slab can provide good micro vibration control performance over 10 Hz for the micro vibration in the vertical direction,and over 5 Hz for the micro vibration in the horizontal directions.Through casting the mass concrete slab,the micro vibration level in the vertical direction can be reduced by 24%,the micro vibration level in the horizontal direction can be reduced by 34%.The control ability of the slab to the horizontal micro-vibration is slightly better than that of vertical micro-vibration.Moreover,simplified two-dimensional finite element models are established to discuss the influence of changing the concrete layer’s density,stiffness and thickness on the slab’s micro-vibration control ability.The simulation results indicate that the increasing thickness of reinforced concrete layer or density of the plain concrete layer has no influence on the micro-vibration control ability of slab in the vertical direction,but has adverse effect on that in the horizontal direction.

关 键 词：精密科学设施 现场测试 大体积混凝土底板 微振动控制 位移有效值 二维有限元模型 

分 类 号：TU375.2[建筑科学—结构工程] TU476