Background Seismic impact on objects of oil and gas complex (OGC) can cause a number of secondary emergency situations of technogenic nature such as explosions, fires, emissions of chemically hazardous objects, etc. Consequences (number of injuries and victims, material damage) from actions of secondary accidents quite often exceed losses from primary impact. Therefore it is necessary to develop unique methodical approaches to assessment of seismic risk taking into account secondary technogenic accidents. Aims and Objectives: • to develop methods of complex analysis of seismic risk taking into account possible accidents on objects of oil and gas complex in destructive earthquakes; • to estimate seismic vulnerability of long distance pipelines in the conditions of information shortage. Methods Objectives were solved by methods of probability theory, statistical analysis and mathematical modelling. Results Methodical approaches to justification of impact models due to various events’ development scenarios are offered. Damage rules for buildings from influence of pressure and impulses at emergency explosions on dangerous objects in case of destructive earthquakes are submitted. Evaluation methods for seismic vulnerability of extended linear objects (pipelines) factored in deficiency of the statistical information that is necessary for creation of damage rules are given. Vulnerability functions for people placed in buildings at accidents on OGC objects from seismic impact are given. Dependencies for an estimation of individual risk are proved. Conclusion The received regularities based on application of impact models and damage rules (destruction law) allow to carry out the complex analysis of seismic risk taking into account secondary technogenic accidents on OGC objects.

Рассмотрены опасности падения на земную поверхность астероидов и других космических тел и возможные последствия их действия на здания, сооружения и системы жизнеобеспечения в городах и населенных пунктах в связи с возникновением интенсивных тепловых воздействий, воздушных ударных и сейсмических волн, способных инициировать землетрясения в сейсмически активных регионах. Рассмотрен сценарий сейсмической опасности, связанный с вероятностью падения астероидов на земную поверхность. Представлены возможные методы и программные средства, позволяющие реализовать системный подход к прогнозированию последствий катастрофических явлений, связанных с падением космических объектов на земную поверхность, а также рассмотрены вопросы планирования средств снижения потенциальных угроз для населения. Проанализированы основные эффекты Челябинского болида. Обоснована необходимость разработки методов обнаружения и мониторинга объектов, сближающихся с Землей, и создания средств защиты Земли от астероидно-кометной опасности.

Background To assess the impact of groundwater changes on the stress state of underground pipelines it is required to inspect periodically the horizontal and vertical position and to determine the bend radius of the route. Aims and Objectives To review existing methods for determining the underground pipes bending radius, to establish their characteristics and weaknesses, to develop improved method for calculating the bending radius according to the survey. Methods The mathematical analysis, finite element method and laws of thermodynamics are used. Results There are some disadvantages of using a geometric approximation in results measurement. A new method that uses the physical modeling of the deformation of the pipeline under the influence of soil reaction is offered. Conclusion The simulation method allows to calculate the bending radius with greater accuracy, not only in the plane but in space.

The mathematical model of interaction between the underground pipeline and the soil within the area of longitudinal displacement (landslide) is developed. By one of examples, the most important regularities of formation of stress-and-strain state of the pipeline in the landslide region are shown. Refs.. Figs.. Tabs..

Background One source of danger to pipelines laid in difficult engineering and geological conditions are groundwater changes, including landslides. The monitoring system of pipelines in such areas must prevent these phenomena, consider the mechanisms and patterns of interaction with the active pipeline ground, supported by modern means of observation and measurement, as well as more sophisticated computational methods. Aims and Objectives to develop a mathematical model of the interaction of the underground water pipelines with soil in the area of longitudinal shear (landslide); to investigate the properties of the differential equation of state of the pipeline in such an area; to develop an algorithm for solving the equation of state in the general case. Methods In deriving the equation of state used the methods of mathematical physics and theoretical mechanics. The state properties is calculated by mathematical analysis. Algorithm for solving the general case is developed using finite difference methods, iterative, successive approximations. Results The developed algorithm is characterized by a feature - in the problem solution it is possible to specify initial and boundary conditions, including the reaction of the soil. There are studied some regularities of the landslide impact on the pipeline. In particular, it was found that the zone of perturbation stress field extends over several hundred meters to each side of the landslide border area.

Background In the operation of underground main pipelines laid in the route sections with complex geological conditions, there may be stripped of pipelines as a result of landslides, karst failures, heaving permafrost. In these conditions it is necessary to evaluate the temperature change of pumped oil into the pipeline to prevent blocking the transport of oil. Aims and Objectives To review the existing methods of determination the thermal interaction between pipeline and environment, to develop an improved method of thermodynamic calculation of the pumped product volume decrease rate in the pipeline. Methods The methods of mathematical analysis, theory of heat transfer in a continuous medium with phase transitions. Results We propose a program for calculating the conditions of transportation of oil in the presence of stripped sections of the pipeline at low ambient temperatures, based on numerical solution of heat conduction for a multilayer insulated objects.

A model based on generation of random unsteady processes (accelerograms) is developed for estimation of the pipeline reliability. Refs.. Figs.. Tabs..

The loads acting on the linear part of main oil pipelines and the internal forces in the material of pipes are considered for complicated loading conditions. Refs. 3. Figs. 3. Tabs. 3.

Background Strength calculation is performed on the pipeline under the different types of loads. In the strength longitudinal-transverse bending calculation trunk pipelines section is assumed as a beam under frictional constraint of horizontal displacements of the sagging plot ends. Aims and Objectives To analyze the stress-strain state of the pipeline filled with oil on the total cross section. To assess the durability of pipeline systems under complicated engineering-geological condi-tions. Methods Strength calculation of pipelines is based on methods of mathematical modeling, when loaded pipeline section is represented as an elastic beam under longitudinal and transverse bending. Results A computer analysis of the stress-strain state of the pipeline and parameters of movement of its linear part, depending on various conditions (of the length of sagging pipeline, contact with soil, temperature gradient, etc.) is comleted. Conclusion The calculation method presented in the paper allows to estimate the durability pipeline in areas with complex geological conditions.