Seismic stability of the underground main pipeline

2011 ◽  
Vol 8 (1) ◽  
pp. 275-286
Author(s):  
R.G. Yakupov ◽  
D.M. Zaripov
Keyword(s):  
Laplace Transformation ◽  
Seismic Waves ◽  
Generalized Functions ◽  
Seismic Stability ◽  
Main Pipeline ◽  
Motion Equations ◽  
Numerical Example ◽  
Earthquake Force ◽  
Deformed State

The stress-deformed state of the underground main pipeline under the action of seismic waves of an earthquake is considered. The generalized functions of seismic impulses are constructed. The pipeline motion equations are solved with used Laplace transformation by the time. Tensions and deformations of the pipeline have been determined. A numerical example is reviewed. Diagrams of change of the tension depending on earthquake force are provided in earthquake-points.

scholarly journals Underground main pipeline behaviour under a travelling impulse in the form of a triangle

2021 ◽  
Vol 264 ◽  
pp. 01006
Author(s):  
Barna Rakhmankulova ◽  
Sayibdjan Mirzaev ◽  
Rakhmatjon Khusainov ◽  
Saparboy Khusainov
Keyword(s):  
Wave Front ◽  
Viscoelastic Model ◽  
Elastic Interaction ◽  
Viscosity Coefficient ◽  
Underground Pipeline ◽  
Main Pipeline ◽  
Soil System ◽  
Maximum Deformation ◽  
Viscous Interaction ◽  
Deformed State

The article presents an analysis of the dynamic response of an underground main pipeline under the action of a longitudinal wave, propagating in soil along the pipe. It is assumed that the elastic pipe has a finite length. A linear viscoelastic model of the "pipe-soil" system interaction is considered. The influence of a pulse in the form of a triangle on the deformed state of an underground main pipeline is investigated. The article presents a comparative analysis of the results obtained for some values of the coefficients of elastic and viscous interaction, the propagation velocity, and the duration of the pulse. In the case of elastic interaction of the "pipe-soil" system, the reflection of the wave propagating in the underground pipeline on the boundaries of the pipeline when it coincides with the wave propagating in the soil leads to an increase in the maximum deformation of the underground pipeline, the value of deformation can double. The viscosity coefficient of interaction at the pipe-soil system contact leads to the wave front attenuation in the underground pipeline. For soils with the coefficient of viscous interaction higher than 100 kN∙s/m2, this leads to complete attenuation of the bursts at the wave front in the pipeline. The influence of the wave propagation in soil on the deformation values at the wave front was also studied.

The impact of temperature change on stress deformed state of a main pipeline surrounded by a viscous medium and affected by thrusts and dislocations of the Earth’s crust

2006 ◽  
Vol 4 ◽  
pp. 32-40
Author(s):  
M.I. Davletov ◽  
Yu.V. Kazantsev ◽  
A.G. Khakimov
Keyword(s):  
Internal Pressure ◽  
Temperature Change ◽  
Viscous Medium ◽  
Earth’S Crust ◽  
Main Pipeline ◽  
Constraint Forces ◽  
Deformed State ◽  
Earth's Crust ◽  
The Impact ◽  
Excess Internal Pressure

The present investigation concerns the movement and stress deformed state of a main pipeline with excess internal pressure surrounded by a highly viscous medium under changing temperature and also in the case of thrusts and dislocations of the Earth’s crust. Account is taken of constraint forces occurred due to excess internal pressure and temperature change.

Vibration Control of the Platform System with Hydraulic Supports

2003 ◽  
Vol 9 (9) ◽  
pp. 1093-1100 ◽  
Author(s):  
Y. G. Tang ◽  
Q. Ding ◽  
Y. S. Chen
Keyword(s):  
Hydraulic System ◽  
Laplace Transformation ◽  
Control Method ◽  
Vibration System ◽  
Stability Criteria ◽  
Motion Equations ◽  
Set Up ◽  
The Time Domain ◽  
Platform System ◽  
Hydraulic Supports

The platform system includes a platform, four hydraulic supports and a unit on the platform. The motion equations for the platform system are set up as the unit on the platform is simplified as one mass element. Based on the Lowes-Hurwits stability criteria, the feedback flow coefficients of the hydraulic system are determined. Then, the Laplace transformation is used to derive the transfer function for this vibration system. The dynamic response both in the time domain and in the frequency domain for the platform system is calculated using this method. The results show that the control method in this paper is practical and reliable to the platform system.

scholarly journals Analysis of Seismic Damage of Underground Powerhouse Structure of Hydropower Plants Based on Dynamic Contact Force Method

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Yang Yang ◽  
Juntao Chen ◽  
Ming Xiao
Keyword(s):  
Contact Force ◽  
Concrete Structure ◽  
Seismic Waves ◽  
Damage Model ◽  
Dynamic Contact ◽  
Seismic Damage ◽  
Surrounding Rock ◽  
Hydropower Plant ◽  
Seismic Stability ◽  
Underground Powerhouse

Based on the characteristics of the dynamic interaction between an underground powerhouse concrete structure and its surrounding rock in a hydropower plant, an algorithm of dynamic contact force was proposed. This algorithm enables the simulation of three states of contact surface under dynamic loads, namely, cohesive contact, sliding contact, and separation. It is suitable for the numerical analysis of the dynamic response of the large and complex contact system consisting of underground powerhouse concrete structure and the surrounding rock. This algorithm and a 3D plastic-damage model were implemented in a dynamic computing platform, SUCED, to analyze the dynamic characteristics of the underground powerhouse structure of Yingxiuwan Hydropower Plant. By comparing the numerical results and postearthquake investigations, it was concluded that the amplitude and duration of seismic waves were the external factors causing seismic damage of the underground powerhouse structure, and the spatial variations in structural properties were the internal factors. The existence of rock mass surrounding the underground powerhouse was vital to the seismic stability of the structure. This work provides the theoretical basis for the anti-seismic design of underground powerhouse structures.

scholarly journals Generalized and Fundamental Solutions of Motion Equations of Two-Component Biot’s Medium

2020 ◽  
Author(s):  
Lyudmila Alexeyeva ◽  
Yergali Kurmanov
Keyword(s):  
Wave Propagation ◽  
Harmonic Oscillation ◽  
Delta Function ◽  
Fundamental Solutions ◽  
Generalized Functions ◽  
Integral Representations ◽  
Generalized Solutions ◽  
Motion Equations ◽  
Two Component ◽  
Water Saturated

Here processes of wave propagation in a two-component Biot’s medium are considered, which are generated by arbitrary forces actions. By using Fourier transformation of generalized functions, a fundamental solution, Green tensor, of motion equations of this medium has been constructed in a non-stationary case and in the case of stationary harmonic oscillation. These tensors describe the processes of wave propagation (in spaces of dimensions 1, 2, 3) under an action of power sources concentrated at coordinates origin, which are described by a singular delta-function. Based on them, generalized solutions of these equations are constructed under the action of various sources of periodic and non-stationary perturbations, which are described by both regular and singular generalized functions. For regular acting forces, integral representations of solutions are given that can be used to calculate the stress-strain state of a porous water-saturated medium.

Seismic safety of large-scale blasting in natural stone quarries

2020 ◽  
pp. 32-36
Author(s):  
S. G. Onika ◽  
◽  
F. G. Khalyavkin ◽  
A. K. Gets ◽  
V. Ch. Orlovsky ◽  
...  
Keyword(s):  
Delay Interval ◽  
Large Scale ◽  
Seismic Waves ◽  
Probabilistic Approach ◽  
Prediction Method ◽  
Natural Stone ◽  
Seismic Stability ◽  
Technical Documentation ◽  
Seismic Safety ◽  
Seismic Impact

In actual practice, reduction of seismic impact of blasts down to safe level is based on standard technical documentation as well as on recommendations developed by research institutions and specialized agencies. Chiefly, these regulations are concerned with limitation of explosive mass. In the meanwhile, blasting efficiency is governed by strength of rock, various degrees of rock mass fracturing and watering, as well as by different seismic stability of close-spaced facilities, which requires application of different kinds of explosives. This article presents a case-study of seismically safe blasting design and justification for Mikashevichi granite quarry based on the PPV prediction in the basement of guarded objects. The quarry zoning is accomplished by the criterion of allowable explosive mass per one delay interval. The probabilistic PPV prediction method is described. The residential and industrial facilities within the seismic impact zone of blasting in Mikashevichi quarry can experience adverse effect of seismic waves during mining advance, which requires introduction of differentiated limitation of allowable explosive mass per one delay interval. The probabilistic approach to blasting pattern design with regard to theoretical distribution of seismicity coefficients ensures the seismic safety of blasting. The developed chart of seismically safe explosive charges per delay interval ensures integrated safety of all guarded objects at the natural stone quarry, with allowance for closer spaced blasting operations and subsequent mining advance.

Block Element Analysis for Earthquake Response of Joint Rock Slope

2012 ◽  
Vol 226-228 ◽  
pp. 1326-1331
Author(s):  
De Sheng Yin ◽  
Wei Xing Qing ◽  
Chun Sheng Li
Keyword(s):  
Seismic Waves ◽  
Rock Slope ◽  
Historical Analysis ◽  
Seismic Stability ◽  
Block Element ◽  
Element Analysis ◽  
Fortran Language ◽  
Block Element Method ◽  
The Relationship ◽  
Element Method

In this paper, the Block Element Method (BEM) for dynamic analysis is developed and applied to historical analysis of seismic stability of a rock slope. Combine the idea of viscous-spring boundary with the theory of BEM, the artificial boundary condition of BEM is formulated, which can eliminate reflection of the seismic waves from the boundaries of the calculating domain. Also, the relationship between the displacement and the stiffness of discontinuous is adopted in the dynamic block element method. The corresponding program is written by FORTRAN language and the application of the intake slope demonstrates the capacity of this method.

scholarly journals The assessment of the tank foundation carrying capacity under the conditions of seismic danger

2018 ◽  
Vol 170 ◽  
pp. 04017
Author(s):  
Natalia Koretskaya ◽  
Nikolay Grib
Keyword(s):  
State Standard ◽  
Carrying Capacity ◽  
Point Of View ◽  
Seismic Stability ◽  
Site Conditions ◽  
Preliminary Assessment ◽  
Limit States ◽  
Similar Construction ◽  
Deformed State ◽  
Made In

The article is devoted to the preliminary assessment of the tank foundation for its carrying capacity and durability as long as this structure is of a high responsibility level. The inspection of the tank foundation was made in order to assess the possibility of building a similar construction. Considering the site conditions, special attention was paid to the seismic stability of the tank. According to the state standard requirements the calculations were made on the basis of all index marks taking into account the main and specific combinations of loads. To define the tank stability for further operation, it was necessary to assess the possible need of strengthening or repairing it from the point of view of its carrying capacity for the first group of limit states as well as the deformed state. By the results of the research the possibility to further re-use the construction has to be resolved by the owner.

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