Experimental Study for Temperature Variation of Bridge Pier in Plateau Area Using Optical Frequency Domain Reflectometer Technology

The temperature variation in the plateau area is very important for the concrete curing of bridge pier. Due to the large temperature difference in the plateau area, the concrete temperature of the bridge pier varies unevenly, which may damage the quality of the bridge pier. Based on the large bridge project of Sichuan–Tibet railway, the advanced optical frequency-domain reflectometer (OFDR) technology is used to monitor the concrete temperature variations of the bridge pier during the 14 days curing period. The temporal and spatial evolution law of the bridge pier concrete temperature is analyzed. The monitoring result shows: the overall temperature variation of the concrete increases first and then decreases. The temperature variation of the bridge pier concrete in upper surface is obviously affected by the atmospheric fluctuation. The temperature variation on the 14th day of cross section center point is lower when it is farther from the upper surface of the pier. The temperature on the 14th day of the cross section edge point on the long axis increases first and then decreases when it is farther from the upper surface of the pier. On the same cross section, the temperature variation of the short-axis edge point is smaller than that of the long-axis edge point.