Dynamic Features of Precast Waffle Slabs in Cleanro om Design

Comparing with traditional cast-in-place waffle slabs, precast waffle slabs have the intrinsic merits of better quality control, shorter construction time, and thus a reduced construction cost. One major concern of their utilization in cleanroom design is whether the dynamic performance of the slabs would meet the desired vibration criteria. In this paper, different types of slab-column connection have been modeled to characterize the wave propagation on the fab level when subject to mechanical and walker excitations. In addition, we have investigated a mock-up facility constructed with precast slabs. The facility has a similar configuration to a typical VC-D cleanroom [1]. Its midbay stiffness, mobility, and transfer functions were identified via instrumented hammer tests. The field data showed good agreement with the finite element simulation results. In the end, we present the vibration evaluations of a generic precast waffle fab, particularly its horizontal performance, to further verify the applicability of the precast design.