Study On Dynamic Response And Protection Measures Of Buried Pipeline Under Vehicle Load

With the rapid advancement of urbanization and the gradual improvement of my country’s infrastructure,the rapid social and economic development will inevitably lead to an increase in the demand for various resources.Pipeline transportation has developed rapidly at home and abroad with its own unique advantages.Widely used in other fields.Due to geographical factors and actual engineering needs,the pipeline needs to be laid below the road surface.Vehicle load has become one of the most important live loads for buried pipelines.Most pipelines are designed with few or no consideration of vehicle loads on buried pipelines Influence,the long-term effect of vehicle load will cause pipeline failure and damage,causing huge safety accidents and economic losses.This paper first conducts field tests on the vertical earth pressure under vehicle load and the dynamic response of buried pipelines.On the basis of field tests,theoretical analysis and numerical simulation of different working conditions are carried out to analyze the vertical earth pressure transmission under vehicle load.According to the law and the mechanical properties of buried pipelines,four load reduction measures are adopted to carry out numerical simulation and analyze the load reduction effect.The main research contents and conclusions of this paper are as follows:(1)Through field tests,the law of vertical earth pressure transmission under different vehicle loads is tested.Theoretical analysis,comparative analysis of calculation examples and actual measured values are used to suggest that the pseudo-static theory pipeline design method cannot meet the needs of modern heavy-duty and overloaded vehicles.And study the vertical earth pressure attenuation law,put forward the best buried depth of the buried pipeline below the road,to ensure the safe operation of the buried pipeline.(2)The stress and deformation of buried pipelines under vehicle load were tested through field tests,and the influence of different vehicle loads,speeds,depths,and pipe diameters on the deformation and mechanical characteristics of buried pipelines was analyzed.The results showed that the vehicle load and the buried depth of the pipeline is the most important factor that affects the dynamic response of the pipeline.The vehicle speed has little effect on the vertical soil pressure and pipeline stress and deformation.The pipelines of different diameters show different characteristics under the same working conditions.(3)Establish a car-road-tube three-dimensional finite element model,simplify the vehicle load to a constant load moving at a constant speed,simulate the field test conditions and compare the results,demonstrate the rationality of the parameters of the numerical simulation,and supplement the test conditions by numerical simulation.Further analyze the spatial distribution of the vertical earth pressure in the roadbed,extract the dynamic stress time history curve of the buried pipeline at different positions under vehicle load,and analyze the deformation and stress change law of the pipeline section of different pipe diameters.(4)According to the field test results and numerical simulation analysis,the principle of load reduction of buried pipelines with four different load reduction measures was compared and analyzed,and the finite element model of the load reduction measures was established respectively.Different load reduction measures such as geogrid and the use of CLSM backfill materials can reduce the load of buried pipelines.The four load reduction measures show good load reduction effects.The laying of concrete slabs and the use of CLSM backfill materials can effectively prevent pipeline fatigue damage.