Test and analysis on the micro-vibration control ability of mass concrete slab
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.
scientific facilities with high precisionfield testmass concrete slabmicro vibration controlroot mean square value of displacementtwo-dimensional finite element model
万方数据
维普
