ABSTRACT
To better cope with the problem of large-scale concrete cracking in the tunnel through the lake, high-performance dual-grating temperature-strain sensors are used to monitor the temperature and strain of concrete on-site by relying on the rapid reconstruction project of Chunshenhu Road in Suzhou. To study the development law of concrete temperature and strain, plot the time-varying curves of temperature and strain. The results show that the temperature and strain changes of concrete can be divided into two stages: a sharp increase stage and a slow decrease stage. And there are obvious fluctuations in the temperature change curve of the outer surface concrete. Under the influence of boundary conditions, the maximum strain of the top plate appears later than that of the bottom plate and side walls. The change of temperature difference between the inside and outside of concrete can be roughly divided into three stages: rapid increase stage, slow decrease stage, and relatively stable stage. In addition, the temperature difference between the center of the side wall and the outer surface is already greater than the specified value of 25°C, and there will be a high probability of temperature cracks. This study innovatively applied the dual grating temperature-strain monitoring method to the construction process of the tunnel through the lake, which overcomes the defects of insensitive temperature-strain monitoring and discontinuous monitoring data of the traditional method at low temperatures. It provides a theoretical reference for the temperature control of large-scale concrete in the tunnel through the lake and has very important economic and engineering value.
