Instrumentation and monitoring of a four-story earth-retaining concrete building

A four-story reinforced concrete building retaining earth on one side and exhibiting large lateral displacement and structural distress was instrumented and monitored for over four years. The rectangular building measuring 52.42 m by 71.32 m is open to the elements and thus subjected to large temperature variation. The application of classical lateral earth pressure theories and analysis methods for back analysis were unsuccessful in predicting the observed behavior of the building. The instrumentation program involved the installation of eight vibrating-wire displacement transducers measuring the building movements in the longitudinal and transverse directions, and 12 electrolytic tiltmeters mounted on the building wall abutting the retained soil backfill to measure the wall rotation. The instruments were equipped with temperature sensors and were connected to an automatic data acquisition system accessible via a remote connection. The monitoring results revealed the presence of a complex soil-structure interaction involving the effects of temperature on the volumetric strains of the building and their effects on the building movements and the development of lateral pressures in the retained earth mass. The results of the monitoring program are presented in this paper.