Experimental Research On Mechanical Properties Of Buried Pipeline For Liquid-conveying Under Differential Settlement

Many factors such as human's over-exploitation of groundwater, vast amounts of rainfall and earthquake lead to deformation of soil which is around pipelines. It shows that the soil deformation, collapse or rupture are generated under comprehensive function of many factors such as non-uniform settlement. Except those, upper soil pressure, traffic load and impact load also lead to pipeline damage excessive deflection beyond the limit.Reasonable design of experiment device simulate the uneven settlement, faults, and the two coupling pipe under the action of mechanical properties tests. The dissertation analyzes the result of the test data above three conditions, concludes that pipeline strain, deformation and stress pipeline characteristics, and summarizes the deformation law of pipeline. Through the contrastive analysis for the above test results concludes that site environmental changes impact on the stress of the pipeline.Based on test results draws the following conclusion: In the situation that under uneven settlement, the buried pipes in the middle of the subsidence area point force and deformation are the largest; the stress just is the opposite of subsidence area, as a result the pipe deformation state presents a wavy. So in the middle of the subsidence area and fixed area near the settlement, joint is the easiest to damage the position of the pipeline. For buried pipeline under the condition of fault, fault plane section nears the biggest stress value, and fault plane tube surface stress is small. From the fault plane along the pipeline length direction, stress value is increased first and then decreased. Under the action of the two couplings, the biggest characteristic is to make the ring to the surface have a large stress value. And in the same settlement, the action of stress and deformation of the underground pipe are bigger than single test results,. Under the action of coupling pipe is more likely to damage, makes the stress of pipeline more complicated, not a simple superposition of two kinds of effects.