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This is a comprehensive subsurface imaging experiment in Newberry, Florida using stress waves. The site is spatially variable and contains karstic surface and underground voids and anomalies. The sensing technologies used comprised a dense 2D array of 1920 DAS channels and a 12 x 12 grid of 144 SmartSolo 3C nodal stations, which covered an area of 155 m x 75 m and were used to record both active-source and passive-wavefield data. The active-source data was generated by a variety of vibrational and impact sources, namely: a powerful three-dimensional vibroseis shaker truck, a 40-kg propelled energy generator (PEG-40kg), and an 8-lb sledgehammer. The vibroseis shaker truck was used to vibrate the ground in the three directions at 260 locations inside and outside the instrumented area, while the impact sources were used at 268 locations inside the instrumented area. In addition to active source data, four hours of ambient noise were recorded using the DAS, while the nodal stations recorded 48 hours of ambient noise in four 12-hour increments over a period of four days. The waveforms obtained from the 1920 DAS channels for every active-source shot or passive-wavefield time block were extracted, processed, and stored in H5 files. These files can be easily visualized using a Python script incorporated with the open-access dataset. Additionally, the three-component data gathered from each SmartSolo nodal station were consolidated into a single miniSEED file, and the data from all 144 nodal stations obtained during each active-source shot or passive-wavefield time block were extracted and saved into a separate folder. We anticipate that this dataset will be a valuable resource for researchers developing techniques for void and anomaly detection using noninvasive, stress wave-based subsurface imaging techniques. 

To accurately describe the dynamic characteristics of bridges, it is important in some instances to take into consideration the flexibility and damping of the soil-foundation system. The ability to evaluate those properties in the field can serve as both a check for the design assumptions, and as assistance in the design of bridges with similar superstructure/substructure loading and soil conditions in the future. The goal of the presented study is to demonstrate the use of large-amplitude shaking as an effective tool in measuring actual response/behavior of bridges, and developing better understanding of the dynamic response of bridge systems. For that purpose, a large-amplitude shaking of a bridge in Hamilton Township, New Jersey, was carried out. The T-Rex, a mobile shaker from the Natural Hazards Engineering Research Infrastructure (NHERI) experimental facility at the University of Texas, Austin was employed to shake the bridge. A large number of sensors, geophones and accelerometers, were installed at various locations on the bridge deck, pier cap, and on the adjacent ground to capture the dynamic response of the bridge system. Furthermore, the results from field testing were used to calibrate a 3D finite element model of the bridge. The model was used to conduct a comparative analysis of the bridge response for the assumption of the bridge with fixed foundation conditions, and the bridge with the consideration of dynamic soil-structure interaction (DSSI) effects. The comparison with the field testing results demonstrate that the fixed foundation assumption model does not fully capture the behavior of the bridge, as opposed to the model with DSSI considerations. 

Boundary conditions of a structure affect its response to dynamic excitations. In most highway bridge designs, the dynamic soil-structure interaction is not considered, with an underlying assumption that bridge piers have fixed-ends. Foundation flexibility, and more importantly radiation damping from the foundation, whether it is a shallow or deep foundation, can significantly influence the response of substructure/superstructure system. This may lead to deviations of the actual response compared to the design assumptions, depending on soil properties and geometrical and structural characteristics of the bridge. Low-magnitude shaking can be used as the means of evaluation of actual dynamic characteristics of a bridge. Moreover, numerical simulations of the same bridge with the same low-magnitude shaking load on the bridge can be used to model the dynamic response of the bridge, with the consideration of the dynamic soils structure interaction. In this paper, a comparison between the actual response of a bridge in Hamilton Township, New Jersey, and results from numerical simulations is presented. The shaking of the bridge was done using T-Rex, a large mobile shaker from NHERI Experimental Facility at University of Texas at Austin. The test setup, and results from both numerical simulations and field-testing are presented and discussed. Experimental results confirm that the FEM model developed is adequate to infer dynamic characteristics through the eigenmode analysis.