Effect of Foundation Rocking on the Dynamic Characteristics of a 30-Story Concrete Shear Wall Building

Abstract

The dynamic characteristics of a structure after the completion of its construction phase can be determined using ambient vibration measurement techniques. A newly constructed 30 stories tall reinforced concrete building in Burnaby, British Columbia, Canada, is tested using this technique. The experimental results reveal the dynamic characteristics of the investigated building including the building rocking and sliding at the foundation level. The method used is the advanced system identification using enhanced signal processing techniques based on the fundamentals of frequency domain decomposition. The paper expands on the technique, from the basics of the test setups to the details of the analysis.

A total of 15 natural periods of vibration are successfully identified including the translational and torsional modes (up to mode 5). The modal estimation is performed using the techniques such as the Enhanced Frequency Domain Decomposition (EFDD), the Curve-fit Frequency Domain Decomposition (CFDD), and the Frequency Domain Operating Deflection Shapes (FDODS); and the outcomes are compared against each other. The modes found from the analytical ETABS models of the building at the structural design phase are then compared and calibrated against the obtained experimental results.

Appendix

This appendix, with respect to the order of presence of Figs. 2.10, 2.11, 2.12, 2.13, 2.14, 2.15, 2.16, 2.17, 2.18, 2.19, 2.20, 2.21, and 2.22, shows the ARTeMIS model of the building, all of the test setups, the deflected translational mode shapes, the torsional mode shapes, and the foundation rocking/sliding modes.

Fig. 2.10

ARTeMIS model of the tested building

Fig. 2.11

Sensor locations and instrumentation for all the test setups

Fig. 2.12

Setup 01, 02, and 03

Fig. 2.13

Setup 04, 05, and 06

Fig. 2.14

Setup 07, 08, and 09

Fig. 2.15

Setup 10 – the specific setup for capturing the foundation rocking and sliding

Fig. 2.16

Mode 1 – X and Y directions

Fig. 2.17

Mode 2 – X and Y directions

Fig. 2.18

Mode 3 – X and Y directions

Fig. 2.19

Mode 4 – X and Y directions

Fig. 2.20

Mode 5 and 6 – X directions

Fig. 2.21

Torsional mode 1, 2, 3, 4 and 5

Fig. 2.22

Foundation rocking, sliding, and combined modes