Change of the pipeline systems structural composition in the conditions of repair and reconstruction may become the reason for their vulnerability in case of emergency situations. Transition to the state of inoperability even of a small number of the systems structural elements can be accompanied by disconnection from the source of some or even all the consumers of the end product.
When planning and conducting repair and reconstruction of the pipeline systems, it is required take into account possible negative effect of structural changes on the behavior of such objects during development of an accident — resistance reduction.
The purpose of the work — assessment of the resistance to mixed damage of the pipeline systems in the conditions of reconstruction, repair of individual technological fragments.
Resistance was assessed by simulation modeling method. Resistance characteristics in the conditions of alternate accidental damage of linear and point structural elements are as follows: average share of linear elements, the damage of which leads to breaking the links of the source with all the consumers; the average share of transport nodes, when blocked, the link between the source and all the consumers is broken.
It is required to assess and consider the consequences of structural elements disconnection from the system during repairs. The possibilities of the developed method of simulation modeling are considered on the examples of assessment of the pipeline systems resistance during scheduled repair of production lines, sections, as well as in the conditions of reconstruction. The need in taking into account changes in the structure and assessing the properties of the pipeline systems in planning and organization of repair work is shown in the article.