The influence of gas pipeline blasting on the pipelines laid in the same ditch

In order to study the influence of pipeline blasting on the performance of the pipelines laid in the same ditch, X90 full-scale gas blasting test was carried out based on the pipeline cracking control test field. In this test, the influence of pipeline blasting on the deformation behaviors and material properties of the pipelines laid in the same ditch was analyzed. It is shown that the blasting of natural gas pipeline can lead to bending deformation and flattening deformation of the pipelines laid in the same ditch, and the ovality is higher in middle section of the pipeline. Under the effect of heat radiation, the performance of the steel pipelines changes significantly. The propagation resistance of cracks decreases, the microhardness rises first and then decreases with the increasing of wall thickness, and the thickness of the heated layer is about 700 μm. Heat radiation can change the microstructure of steel pipes obviously. The crystalline grains in the surface structure of heated position get coarse, the original growth orientation changes, and the structure in the deep part changes less.