The Permafrost Temperature Study Of An Automatic Testing System And The Modeling In Qinghai-Tibet Railway

Aimed at the influence of variable state of the high-altitude and low-latitude permafrost on the safety of the Qinghai-Tibet Railway, in order to ensure the realization of railway engineering, testing of permafrost temperature becomes a key subject presently. After examining the achievement of permafrost study nationwide and worldwide, an automatic testing system of permafrost temperature has been designed, containing a master computer and some slave computers as follows.Firstly, thermistors are used as temperature transducers and are arranged at testing points along vertical direction of the test location. The slave computer consists of an MCU module, a time system, an AD module, a memory system, a gating module, a communication system, a power managing system, a humidity testing system and a source testing system, thus, acquiring the timely collected permafrost temperature data. Meanwhile, using the ADO database, communications and other technology, the master computer can analyse the variable parameters of the permafrost temperature.Secondly, applied to Qinghai-Tibet Railway, the automatic testing system of permafrost temperature has realized kinds of data processing such as the computation, management and analysis with the help of C++ Builder and database. Taking some locations for examples of testing permafrost temperature, the various characteristics of permafrost temperature in testing holes are analyzed.Finally, using the collected data, a BP model has been determined to predict permafrost characteristics, and support the operation safety of the Qinghai-Tibet Railway. Taking the permafrost temperature of the cross section of DK1278 for an example, the prediction model of temperature satisfies the requirements of engineering accuracy.