DATA ACQUISITION AND TRANSMISSION FOR REMOTE MONITORING OF BRIDGE STRUCTURES

Abstract

In order to study long-term and short-term characteristics under different loading and then to evaluate the performance of a bridge structure, we need to carry out continuous monitoring of relevant parameters. In this dissertation, important performance parameters like strain and vibration as well as influencing parameters like temperature profile, wind speed and speed of vehicle running on the bridge are considered for monitoring bridge structure. Different types of transducers/sensors for measurement of these parameters are carefully selected. For strain measurement, electrical resistance strain gages and vibrating wire (VW) strain gages are selected. For temperature profile, thermocouple and resistance temperature detector (RTD) are selected. For vibration measurement, strain gage type accelerometer is selected. For wind speed measurement, cup-type and vane type anemometers are selected. Vehicle speed measurement was carried out by using two proximity optical sensors. In this dissertation, data acquisition scheme is implemented with some of the transducers/sensors mentioned above Transducers/sensors are connected to Remote Data Acquisition Modules (RDAMs) through signal conditioning units where necessary. These RDAMs are networked to Central computer through RS-485 link for data acquisition. Data is collected by RDAMs from transducers whenever the central computer requests for data. Data acquisition software is written using C-language. The data so collected is stored.in specified format in data files. The possibilities of data transmission between computers through telephone lines and Internet have been examined.