Experimental Studies On Eccentric Bent Of Water Supply Pipeline Socket And Spigot Rubber Joint

As a important part of the urban lifeline systems engineering, the urbanunderground pipeline network system has an impact on the Support of city functionsystem and national economy and the people’s livelihood. When some strongdisasters(earthquake.etc) occur, any parts of the underground pipe network systemmay be damaged and its function likely fail, which could result in some secondarydisaster(fire, flood. etc), these will have great impact on people’s life and propertysecurity. Many earthquake damage shows that the fail of the pipe interface is the maindamage. So, carrying out the mechanical property of rubber gasketed joints insegmented pipeline has the important significances.Based on the current study of the underground pipeline at home and broad, thetension-bending coupling tests have been carried on our common water supply systempipe flexible joint ductile iron apron in this paper, and the mechanical behavior, thedeteriorating mechanism and all kinds of limit state of the pipe interface wereanalyzed under tension-bending coupling effects. The main research work carried outas the following:1. Related research status at home and broad was summarized, the failurecharacteristic and the influencing factor of the underground pipeline were analyzedwhen the earthquake strikes, the failure mechanism and the failure mode were stated.2. The tension-bending coupling tests had been carried on this pipe whichdiameter is DN150under different eccentricity of e=25mm, e=50mm and e=180mmwith no water, the drawing force, the axial displacement, the lateral displacement,bending moment and corner of the pipe interface were determined in the course of theexperiment, which obtained the relational curves between the drawing force and theaxial displacement and between the bending moment and corner, the mechanicalcharacteristic and the failure limit state were also analyzed.3. Based on the least squares theory, this paper fitted the relational curvesbetween the drawing force and the axial displacement and between the bendingmoment and corner under different test conditions, and the difference betweenexperimental data and the fitted value was contrastively analyzed.4. Based on the BP(BACK Propagation) principle and model building method ofneural network, three relations among the drawing force, the axial displacement and the lateral displacement was analyzed, and the difference between the measured valueand the BP fitted value was contrastively analyzed, the mechanical model of thetension-bending coupling was put forward for the pipe interface.