With the development of the national economy, the amount of the petroleum, natural gas and other energy demand in China grow with each passing day. In order to meet the national demand for energy, it is necessary to increase the scale of pipeline construction. The composition of the soil around the buried pipeline must be extremely strict to protect the pipeline and anti-corrosion layer effectively from impact and abrasion. However, In some worse geological condition mountainous areas (such as rocky desertification area) where suitable backfill soil is unable to find, backfill soil and crushed gravel should transport a long-distance, which cost more construction money and time. Based on this background, a kind of high strength, impact resistance, easy construction material is developed and researched for protect pipe instead of traditional backfill method. The main research results are as follows:(1) The test schemes of mixture ratio of protective cover materials were made by single factor experiments with seven groups of combination experiments. By simple supported beam impact test, the effect tendencies of protective cover material components on the impact properties of the materials. A good and new kind of protective cover material was developed with low density, fine and uniform bubble, and moderate relative density, whose compressive strength is 230kPa and impact strength is 15.9J. There is not corrosive effect between the protective cover material and PE anti-corrosion layer of pipeline, which could coexist forever.(2) The dynamic responses of pipeline were researched by indoor model test when the protective cover material was subjected to impact load. The increment tendencies of subsidence depth and pipeline stress of protective cover material with the increment of impact times and thickness of protective cover material were obtained, and the increasing coefficients of pipeline stress with different thickness of protective cover material were also obtained. With the help of FEM software ABAQUS, the dynamic change laws of pipeline were analyzed with different thicknesses of protective cover material, different pipeline diameters, and different hammer drop height. Combined with the analysis of increasing coefficients of pipeline stress, the optimal thickness of protective cover material should be 5 cm to 8 cm.(3) Some loading modes were taken into the field model test, such as stone backfill, vehicle rolling, and hammer impact. The effects of that there is or is not protective layer on the PE anti-corrosion layer of pipeline, the pipeline stresses, soil pressure, pipeline vibration acceleration were comparative analyzed. When using the field stones to backfill, the protective layer have significant protective effect on pipeline, which could greatly reduce the dynamic response of pipeline and protect the PE anti-corrosion layer. When the hammer was dropping on the upper soil of pipeline, the protective effect of protective layer is lower than the former situation. And when the vehicle was rolling on the upper soil of pipeline, the protective layer has a same protective effect on the pipeline. Overall, the protective effect of protective layer is better than soil.(4) Combining with the characteristics of the protecting material and designing the system of construction equipment, it is given two construction methods and construction process, which are spraying construction and pouring construction.(5) The economy of protective cover materials and traditional grinded earthwork and commercial backfill were quantitatively compared. The results show that the economy of protective cover materials is better than the economy of other materials, and the protective cover materials could improve the security of the PE protective layer and the pipeline and reduce the risk of pipeline damage and burst, and the protective cover materials could avoid potential risk and loss and reduce the maintenance probability, which could improve the economy of the protective cover materials indirectly. |