Displacement Monitoring System Of The Hydropower Tunnel Surrounding Rock Based On Wireless Sensor Network

Tunnel construction of hydraulic engineering is a complex project with arduous conditions, and it covers major unstable factors. The stability of the underground cavity is influenced by the factors of ground stress, geologic configuration and mechanical properties of the rock mass and underground water. The method of managing the construction safety simply by experience cannot meet the requirements of modernized construction management. Therefore, enhancing the safety control of the tunnel construction of hydraulic engineering appears to be particularly important.Based on the analysis of the development history, research status and current practical application status of the hydraulic engineering safety monitoring technology, this research designed a set of surrounding rock displacement monitoring system of the hydropower tunnel on the basis of Wireless Sensor Networks. In this article, the whole displacement monitoring is accomplished through the acquisition node of displacement sensor, information transfer node of Wireless Sensor Networks, monitoring station and monitoring and management platform. By means of collecting displacement information by the displacement sensor, real-time transmission by Wireless Sensor Networks, monitoring displacement by the monitoring station and control and management platform, and setting up the allowable maximum displacement threshold value of different types of surrounding rocks, the monitoring station and the control and management platform will give an alarm simultaneously while the displacement is overloading.As to the hardware design part of the system, the magnetostrictive linear displacement sensor of high reliability and low power processor Microcontroller MSP430F5418 is applied to while the chip CC1100 is served as the wireless transmission module. The chip LPC1758 of the high performance processor utilized for the monitoring station and the chip DM9161 A served as the physical layer transmitter for the Ethernet transmission unit, are in charge of establishing the communication with the ground server. The function of the acquisition node and the monitoring station will be realized by constructing the lower-computer software platform and then compiling by means of C language modular design.With the characteristics of low cost, small volume and dynamic self-organization, Wireless Sensor Networks is suitable for the information transmission under the special environment of hydraulic tunnels. Adding the relay node under the non-uniform in-situ stress by adopting the concept of the equidistant gradient division and clustering according to the gradient for the Wireless Sensor Networks routing protocol has solved the problem of consuming the networks energy nonuniformly under the long and narrow environment of the hydropower tunnel. Being an object-oriented programming visual language, Visual Basic 6.0, served as a language constructed and developed by the system monitoring and management platform, helps the management platform realize a series of functions of nodes query, configuration, data storage, forecasting and giving an alarm etc.In the ending of this article, by simulating the true environment, performance tests are made to the system in respect of on-line testing, networking communication, error test and alarm test. The effectiveness and steadiness of this system has been verified by means of testing data.