Experimental study of vertical vibration and control on floor slabs caused by vehicle access to upper floors

Vehicles traveling directly on structural slabs occur in large-scale buildings such as transportation hubs and port buildings, imposing dynamic loads on these structures directly. The superposition of large structural spans, multi-level traffic flows, high vehicle density, complex building functions, and occupant concentration markedly amplifies vehicle-induced vertical floor vibrations, resulting in significant vibration comfort problems. Characteristic of this problem is that vibration is directly input to structural components, consequently facilitating rapid transmission via beams and columns through shortened transmission paths. Unlike conventional studies on traffic-induced ground-borne vibration, where vibrations are transmitted to buildings through the soil-foundation system, this study focuses on a direct-input scenario in which vehicle-induced dynamic loads are applied directly to structural floor slabs. Moreover, although floating slab systems have been widely used in railway tracks and municipal roads, their applicability to floor slabs within building structures remains insufficiently investigated. Therefore, this paper presents an experimental study on vehicle-induced floor slab vibration. The specimen was a five-story three-span structural model, and the tests included floor vibration tests caused by vehicle-induced ground vibration, tests of vehicle traveling on the floor slab, and tests of vehicle traveling on the floating slab. The vehicle simulation loading system was established to simulate the vehicle moving dynamic loads. The differences in vertical floor vibration induced by vehicle on the ground and vehicle access to upper floors were discussed. The time-frequency transmission characteristics of vibrations throughout various floors were analyzed. And the vibration isolation effects of steel spring floating slabs and polyurethane floating slabs were compared and verified. The results indicate that vibration of the floor slab is significantly amplified and difficult to mitigate due to the vehicle access to upper floors. With the increase of vehicle speed, the predominant frequencies expand from 10 to 40 Hz to 60–70 Hz, and the use of floating slab system can effectively reduce the vibration input to the structure. Vibration isolation efficacy exhibits frequency-dependent characteristics. The polyurethane floating slab, with a design frequency of around 11.40 Hz, reduces the peak acceleration by around 60%-70%. The design frequency of the steel spring floating slab reaches 3.78 Hz; therefore, the peak acceleration is reduced by around 80%-90%. The research provides benchmark or test data support for the problem of floor vibration and control caused by vehicle access to upper floors.