324 M.J. Wesolowsky et al. 1 10 100 1000 10000 100000 1000000 1 10 100 1000 L1 Particle Velocity, micrometer/s Distance (m) Measured Values Fit (Measured Data) SAP2000 Model Values Fit (SAP2000 Data) Fig. 40.3 Vibration attenuation through one wing of the building Fig. 40.4 SAP2000 model of the hospital wing of the wings is shown in Fig. 40.3. This wing is a steel-framed building built in 1956 with concrete decking and both steel and concrete columns. To confirm the accuracy of the measured values within the building, a SAP2000 finite-element model of the structure was also created and is shown in Fig. 40.4. The measured and expected vibration levels from SAP2000 match quite closely, as is shown in Fig. 40.3. Comparing Figs. 40.2 and 40.3, the velocity vs. distance slope is much shallower within the building as compared to outside the building. This suggests that vibration attenuates more in soil as opposed to through the concrete and steel structure of this particular building. Along with the change in vibration propagation through the structure of the building, it was observed that a significant loss in vibration amplitudes occurred as the vibrations travelled from the exterior soil into the building foundations. As such, it can be said that the construction-induced vibration goes through three different stages, all with different rates of reduction over distance: (1) reduction through soil, (2) amplitude drop during transmission from soil to the building foundations, and (3) reduction through propagation within the building structure.
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