Design And Performance Test Of Buried Pipeline And Soil Interaction Laboratory

With the continuous increase of buried depth,the change of temperature difference and the decline of its own resistance,under the action of external forces,the plastic pipeline has exceeded its capacity,and then problems occur,which is an irreversible slow catastrophic process.Therefore,it is necessary to study and test the stress change of plastic pipe,evaluate the performance of the pipe,guide the scientific and reasonable construction,and improve the reliability and stability of plastic pipe.In this paper,according to the test demand of buried plastic pipe,according to its characteristics,a set of soil laboratory for buried plastic pipe is designed.At the same time,the steel belt polyethylene spiral bellows are selected as the research object to test the performance of pipe.(1)The stress of buried pipe is studied and analyzed,and the stress and deformation of buried pipe under different weather and working conditions are studied.The soil arching effect is formed between the buried flexible pipe and the soil,which is not easy to be damaged compared with the rigid pipe.Under the condition of compacted soil,the vertical deformation of pipeline is small,the stability of pipeline is better,and it is not easy to be damaged.(2)The first large-scale soil laboratory of buried pipeline in China was established to study the interaction between pipe and soil.The laboratory was composed of box structure,control system and hydraulic system.Through the selection of structure scheme,analysis and optimization,finally determine the u-shaped integral hinge axle box body structure,as well as the laboratory has carried on the design and optimization of the hydraulic control system,has carried on the design of the control system,the controller chooses CP1 H omron brand-XA40DR-type A PLC controller,the product has 40 points(24 input points,16 output points),at the same time have 50/100 KHZ high-speed count function,can satisfy the requirement of vibration frequency.(3)Taking DN1000 steel tape reinforced polyethylene spiral bellows as the research object,the stress relaxation and performance limit under different soil pressure were tested in the established soil laboratory to determine the stress relaxation characteristics and fixed deformation and failure data,as well as the failure degree of the pipe under continuous pressure.According to the test,when the pipeline deformation is 5%,the pressure inside thecylinder is about 8.11 mpa and the pressure applied to the soil is 6082.5k N,which is equivalent to the overburden depth of 17.36 m.Pipe on the limit depth,appears in the pipe will be backdated to the elliptical deformation(including a pit),DN1000 pipeline in the embedded depth of 36.34 m(17000000 Mpa),12 o 'clock direction appear recurvatum,at 3 o 'clock and 9 o 'clock direction does not appear damage,pipe 134 mm maximum vertical deformation,deformation rate 13.44%,so the 1000 pipes buried deeply limit of 36.34 m.The experiment not only verified the design function of soil laboratory,but also tested and collected the deformation data of steel bellows reinforced polyethylene spiral pipe under different pressures,and verified and determined the ultimate buried depth of pipe.