Study On Type Identification And Location Technology Of Third Party Damage In Gas Transmission Pipeline

With the acceleration of local economic construction,the third-party damage of gas pipelines becomes more serious.According to the characteristics of the third-party damage,such as concealment,diversity and randomness,so the third-party damage is difficult to control.With the expansion of urban construction,building operations and land development as well as other activities on the ground occur frequently,which poses a great threat to the safe operation of gas pipelines.In this paper,we made type division for the third-party damage events which exists along gas pipeline,and the eigenvalues of different vibration types are determined.We made sensor fiber realize signal detection by use of principle of dual Mach-Zehnder,and software LabVIEW was established to analysis and process the received light signal,final determined the type and locate of the third-party damage event.The main research work is as follows:(1)Investigating overseas and domestic literatures about monitoring technology and application status of third-party damage,adaptation and application status of relevant monitoring equipment as well as monitoring methods about third-party damage were tracked and searched.We investigated and surveyed the relevant literatures from overseas and domestic,the research results of related literature are compared and summarized.(2)The main factors influencing third-party damage of gas pipeline are analyzed,and the common third-party damage events are summarized into the artificial digging,mechanical mining,mechanical picks work,the overload vehicles passed,pile driving dynamic compaction and explosion work basic vibration events,the characteristics of vibration signal generated by different basic vibration events are analyzed according to signal strength,signal frequency,duration of operation,the average operation time interval and a single average operation time vibration eigenvalues.(3)We studied the type and characteristics of vibration wave which is generated by the third-party damage.In light of characteristics of energy attenuation of vibration wave in soil,we established the soil vibration model and the optical cable forced vibration model,and analyzes the optical signal changes after the vibration.(4)The monitoring principle of distributed sensor fiber was analyzed,and the practicability of different optical fiber monitoring methods was compared.Monitoring way with Mach-mach-zehnder interference principle was chosen for gas pipeline third-party damage type identifying and locating monitoring,and hardware deployment way in the monitoring system was designed.Three kinds of cable laying methods for third-party damage monitoring were compared and selected,and the laying methods of optical fiber crossing the special section were designed.(5)Samples of vibration signals were collected from different third-party damage types,we used BP neural network to train the collected vibration parameters,to realize type differentiation of third party damage.Time difference between two optical signals is determined by cross-correlation calculating,so as to locate the position of third-party damage.Based on the constructed monitoring system platform of third-party damage,the third-party damage type recognition and location were realized.(6)In light of the situation of third-party damage along the DM gas pipeline,the dual Mach-Zehnder interference monitoring system was designed to apply along the pipeline for monitoring of third-party damage.The artificial simulation experiment of third-party damage along the pipeline was carried out,threshold values of the software system was tested,the statistical monitoring results from the third-party damage of the DM gas line were analyzed and evaluated.