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The operation of subway trains induces ambient vibrations, which may cause annoyance and other adverse effects on humans, eventually leading to physical, physiological, and psychological problems. In this paper, the human annoyance rate (HAR) models, used to assess the human comfort under the subway train-induced ambient vibrations, were deduced and the calibration curves for 5 typical use circumstances were addressed. An autonomous measurement system, based on the Imote2, wireless smart sensor (WSS) platform, plus the SHM-H, highsensitivity accelerometer board, was developed for the HAR assessment. The calibration curves were digitized and embedded in the computational core of the WSS unit. Experimental validation was conducted, using the developed system on a large underground reinforced concrete frame structure adjoining the subway station. The ambient acceleration of both basement floors was measured; the embedded computation was implemented and the HAR assessment results were wirelessly transmitted to the central server, all by the WSS unit. The HAR distributions of the testing areas were identified, and the extent to which both basements will be influenced by the close-up subway-train's operation, in term of the 5 typical use circumstances, were quantitatively assessed. The potential of the WSS-based autonomous system for the fast environment impact assessment of the subway train-induced ambient vibration was well demonstrated.

Taizhou Bridge is the world’s first kilometer-scale three-pylon suspension bridge. To minimize the impacts on navigation, a longitudinal herringbone steel pylon was adopted in the middle of the bridge without additional piers. This structure is unique, and little research has focused on its structural condition assessment. In this paper, eighty fiber Bragg grating strain sensors were deployed along the height of the steel tower to collect strain data about the key components and to monitor the pylon’s structural condition. Because temperature-induced strain contributes little to the stress in the pylon, the empirical mode decomposition method was proposed to remove the noise and the temperature-induced strain, leaving the dynamic strain response. The frequency characteristics were obtained from both the dynamic strain and the raw strain, and they show good agreement. A statistical analysis was adopted assuming that the extracted dynamic stress peaks and valleys were normally distributed. The expected maximum values from the statistical analysis were compared with the measured maximum values at different heights, and they agree well with each other. The maximum compression and tension of the key segments of the middle tower exhibited considerable redundancy, which indicates that the middle pylon is in good condition.

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