A system of equations describing the oscillations of a rectilinear pipeline that interacts with the surrounding soil in the case of seismic action functioning in an arbitrary direction is presented. A numerical implementation of problems related to the determination of the mode of deformation of a pipeline experiencing seismic movement of the soil is performed. The methods of realization of boundary problem of seismodynamics of underground pipelines at arbitrary direction of seismic load are developed, as well as the methods of realization of the problems of seismodynamics of underground pipelines of non-orthogonal configuration, based on Finite deference method.
This study is devoted to the assessment of the stress state and dynamic characteristics of various structures. The actual task at the design stage is to determine the parameters of a structure. In this article, a mathematical model was developed for assessing the stress state and dynamic characteristics of plane and spatial structures based on the Lagrange variational equation using the d’Alembert principle. The variational problem for the structures considered by the finite element method leads to the solution of nonhomogeneous algebraic equations or to the solution of algebraic eigenvalue problems. To assess the adequacy of the model and the accuracy of the numerical results obtained, a plane and spatial test problem with an exact solution was solved. Using the proposed model, the eigenfrequencies and modes of oscillations of the gravitational and earth dams (296 m high) of the Nurek reservoir were investigated. At that, it was revealed that in the natural modes of vibration of earth dams, the greatest displacements under low frequencies are observed at the crest part or at the middle of the slopes.
The new approach for numerical calculating of stress and strain state of underground structures is presented in this issue. The advantage of this method is using in design scheme a real diagram of concrete and reinforcement materials. Also, these calculations are allowed to trace the process of deformation of reinforced concrete in each of the sections of the structure. In the technique, static calculations of reinforced structural elements when changing their initial conditions or stress state after strengthening are carried out taking into account new data. A three-dimensional finite element calculation is also carried out while taking into account regulatory loads. Assessment of levels of tangential and tensile stresses in walls makes it possible to target reinforcement and parameters of monolithic stiffness belts. Numerical results for discussion are presented in this paper.
Central Asian region is an earthquake prone zone. At water management engineering, one of the central and great role play dams, water supply systems, etc. The seismic safety of these objects has great importance. In areas subject to seismic effect, the cases were observed when such structures were significantly damaged, and in some cases even destroyed. It leads to the long-term shutdown of the main water supply systems and it causing great material losses. The main aim of the issue is an analysis of the effects of strong earthquakes for waterworks facilities, proposing measures that are necessary for the urgent determination of the technical condition of an operating structure and the development of recommendations for further safe operation. There were considered lessons from past events also and strategies for sustainable development in the future by taking into account local features.
The article is devoted to studying the stress-strain state (SSS) and assessing the strength of the Gissarak, Sokh, and Pachkamar earth dams in a plane statement under the action of body forces and hydrostatic pressure. A mathematical model, algorithm, and computer program for studying the stress-strain state and assessing the strength of structures are developed in the article using the Lagrange variational equation. The finite element method was used in the problem solution. The adequacy of the model and the accuracy of the algorithm and program were verified by solving several test problems. It was revealed that the stress-strain state and strength of the studied earth dams significantly depend on the physical and mechanical properties of soils, the commensurability of geometric dimensions and slope coefficients of the dam retaining prisms, and on the level of water filling in reservoirs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.