Research On Several Kinds Of Typical Fracture Defect Plastic Drainage Pipes

Town drainage pipeline in the process of daily use, can form a broken line defect. The fracture defects affect how drainage pipelines carrying capacity, is in the drainage pipeline detection and evaluation to solve one problem. The current domestic research on drainage pipeline rupture defect is limited. This paper focuses on several typical fracture defect plastic drainage experiment study and theoretical analysis.Combined with existing national standards and drainage pipeline defects in practical engineering, designing and completing a batch of defective plastic drainage pipe specimen,And determining the specimen are ring stiffness, compressive strength and the damage load under external pressure. According to the classical theory of fracture mechanics, the experimental results of measured through theoretical analysis. Validation of the urban drainage pipeline detection and evaluation technology regulations for drainage pipe burst in the levels of classification and analysis of different fracture defects on the bearing capacity of the plastic drains.The results show:(1)On the plastic drainage pipe hoop direction, a broken2levels of fork flaws and broken four grade1fork on the bearing capacity can be thought of as equivalent, with the "regulations of urban drainage pipeline detection and evaluation technology, the fracture defects on criteria consistently; A broken4circular defects and seven level3circular defects on the bearing capacity can be thought of as equivalent, the grade and specification of rupture defect standard there is a big gap.(2) For plastic drainage pipeline y type crack, through the study found that the crack Angle at120degrees has the greatest effect in the radial bearing capacity of pipeline, pipeline is the most dangerous. The longer the crack length, pipe main radial compressive ability is poor;The longer the crack length, pipe main radial compressive ability is poor; Time the longer the crack length, pipe radial compressive ability more bad, but compared to the main crack, a crack of pipe has little effect on the radial load capacity. (3) For plastic pipes parallel cracks, through the study found that crack rate of interlaced on the bearing capacity of the drainage pipeline affect by the interference of the crack spacing. The two crack spacing, the greater the crisscross or two crack spacing is smaller, the more of the less radial bearing capacity of the specimens is weak, structure the more dangerous. Parallel to the crack spacing, the greater the radial bearing capacity, the worse plastic drainage pipe, structure the more dangerous. Parallel to the crack depth, the greater the radial bearing capacity, the worse plastic drainage pipe, structure the more dangerous.(4) The defect level and the number of defects are the same situation, defects in the pipe wall than the influence of the defects in the pipe at the top of the damage to pipeline is greater. The defect level and the number of defects are the same situation, defect distribution more uniform symmetry, the greater the damage effect of the pipes. The defect under the condition of the same size, pipe square holes and round holes of the dangers of plastic pipes.