This paper investigates the problem of wireless power transmission in underground pipeline detection systems. In response to the fact that during the study of the underground pipeline detection system, the coil inductance value changes due to environmental and anthropogenic factors, making the system detuned and unable to effectively acquire the underground microtag ID signal. Therefore, we raised a novel capacity compensation method to solve the problem mentioned above. Firstly, the hardware structure of the system is modelled, derived and analysed with the system in a resonant state. The topology applied to the system is then subjected to capacitive compensation operations to obtain the power transfer efficiency of the system in the resonant state with the best topology model. Finally, it is demonstrated through functional tests that the capacitive compensation of the optimal topology model achieves a good power transfer performance and acquires an effective ID signal.

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To reveal influences of hydration heat in large-volume concrete, a large-volume concrete pile cap of a main bridge over a canal was taken as the engineering background. In the research, the finite element software, Madis civil, was used for simulation and analysis of hydration heat in the pile cap. Through finite element simulation, the temperature and stress fields were obtained and compared with the monitored data. Analysis results indicate that in the initial pouring stage of the pile cap, a large temperature difference occurs between the interior and surface of the pile cap; as the temperature difference enlarges, the temperature stress of the pile cap also increases correspondingly. The results of finite element analysis match well with the monitored data, which guarantees the construction quality in the field and verifies feasibility of the finite element software in simulation and analysis of hydration heat.