Research on Influence of Sediments Mechanical Parameters of Seismic Arch Dams

2012 ◽  
Vol 594-597 ◽  
pp. 1998-2002
Author(s):  
Yi Zhi Yan ◽  
Zhi Min Su ◽  
Liang Wu
Keyword(s):  
Seismic Response ◽  
Pressure Wave ◽  
Friction Angle ◽  
Arch Dam ◽  
Response Magnitude ◽  
Mechanical Parameters ◽  
Two Phase ◽  
Arch Dams ◽  
Consolidation Theory ◽  
Phase Medium

The problem of sediments on seismic response of arch dams was not solved. Thus pressure wave formula of saturated porous fluid-solid two-phase medium was applied from the Bait’s consolidation theory, and was determined the seismic response magnitude of sediment on arch dam. And the method was applied to analyze the influence of sediments thickness, cohesion and friction angle on dam seismic response. The result shows sediments is relatively obvious on arch dam seismic response.

Influence of Sediments Characteristics on Seismic Response of Concrete Dams

2013 ◽  
Vol 368-370 ◽  
pp. 1374-1378
Author(s):  
Yi Zhi Yan ◽  
Zhi Min Su
Keyword(s):  
Seismic Response ◽  
Pressure Wave ◽  
Friction Angle ◽  
Response Magnitude ◽  
Concrete Dams ◽  
Two Phase ◽  
Concrete Dam ◽  
Consolidation Theory ◽  
Phase Medium

To solve the problem of sediments on seismic response of concrete dams, pressure wave formula of saturated porous fluid-solid two-phase medium was derived from the Biots consolidation theory, and was determined the seismic response magnitude of sediment on concrete dam. Sediment was regarded as elastic-plasticity. And the method was applied to analyze the influence of sediments density, cohesion and friction angle on dam seismic response. Finally, a typical example is analyzed. The result shows sediments plasticity is relatively obvious on dam seismic response.

Study of Elastic-Plastic Sediments on Seismic Response of Concrete Dams

2013 ◽  
Vol 275-277 ◽  
pp. 1451-1455 ◽  
Author(s):  
Yi Zhi Yan ◽  
Jian Fei Xiao ◽  
Zhi Min Su
Keyword(s):  
Seismic Response ◽  
Pressure Wave ◽  
Friction Angle ◽  
Response Magnitude ◽  
Concrete Dams ◽  
Two Phase ◽  
Concrete Dam ◽  
Consolidation Theory ◽  
Phase Medium ◽  
Biot’S Consolidation

To solve the problem of sediments on seismic response of concrete dams, pressure wave formula of saturated porous fluid-solid two-phase medium was derived from the Biot’s consolidation theory, and was determined the seismic response magnitude of sediment on concrete dam. Sediment was regarded as elastic-plasticity. And the method was applied to analyze the influence of sediments density, cohesion and friction angle on dam seismic response. Finally, a typical example is analyzed. The result shows sediments are significant on dam seismic response.

Analysis of Porous Media Sediments on Seismic Response of Concrete Dams

2013 ◽  
Vol 631-632 ◽  
pp. 576-583 ◽  
Author(s):  
Yi Zhi Yan ◽  
Zhi Min Su
Keyword(s):  
Porous Media ◽  
Seismic Response ◽  
Pressure Wave ◽  
Response Magnitude ◽  
Concrete Dams ◽  
Two Phase ◽  
Concrete Dam ◽  
Consolidation Theory ◽  
Phase Medium

To solve the problem of sediments on seismic response of concrete dams, pressure wave formula of saturated porous fluid-solid two-phase medium was derived from the Bait’s consolidation theory, and was determined the seismic response magnitude of sediment on concrete dam. The method was applied to analyze the influence of sediments thickness and permeability on hydrodynamic pressures. Finally, a typical example is analyzed. The result shows sediments are able to decrease hydrodynamic pressures.

scholarly journals The Effect of Shear Sliding of Vertical Contraction Joints on Seismic Response of High Arch Dams with Fine Finite Element Model

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Shengshan Guo ◽  
Jianxin Liao ◽  
Hailong Huang ◽  
Hui Liang ◽  
Deyu Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Seismic Response ◽  
Element Model ◽  
Arch Dam ◽  
Slip Condition ◽  
Dead Load ◽  
High Arch Dam ◽  
Arch Dams ◽  
Contraction Joints

The contraction joints of arch dams with and without shear keys are simplified to be with no-slip condition and with relative sliding condition, respectively. Based on the Lagrange multiplier method, a contact model considering the manner of independent cantilever dead load type with no-slip condition and relative sliding condition is proposed to model the nonlinearities of vertical contraction joins, which is special to the nonlinear analysis of arch dams considering the manner of dead load type. Different from the conventional Gauss iterative method, the strategy of the alternating iterative solution of normal force and tangential force is employed. The parallelization based on overlapping domain decomposition method (ODDM) and explicit message passing using distributed memory parallel computers is employed to improve the computational efficiency. An existing high arch dam with fine finite element model is analyzed to investigate the effect of shear sliding of vertical joints on seismic response of the arch dam. The result shows that the values of maximum principal tensile stress under relative sliding condition are significantly greater than those under no-slip condition.

scholarly journals Analysis of the Foundation Slab Settlement of the “Africa Pavilion” Facility in Wrocław

2015 ◽  
Vol 37 (4) ◽  
pp. 47-55
Author(s):  
Eugeniusz Sawicki ◽  
Tomasz Strzelecki
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Calculations ◽  
Soil Consolidation ◽  
The Finite Element Method ◽  
Two Phase ◽  
Foundation Slab ◽  
Consolidation Theory ◽  
Phase Medium ◽  
Biot’S Consolidation

Abstract This article presents the results of numerical calculations of soil consolidation underneath the “Africa Pavilion” structure in Wrocław Zoo, Poland. To determine the deformations of the baseplate of the “Africa Pavilion” and deformations of the subsoil, Biot’s consolidation theory for two-phase medium was applied. The calculations were carried out using the professional program FlexPDE v.6, which is based on the Finite Element Method. Numerical calculations performed were used to evaluate the design assumptions allowing for the laying of hydraulic conduits under the slab.

Analysis the Influence of Layered Sediment on Seismic Responses of Concrete Dam

2013 ◽  
Vol 838-841 ◽  
pp. 1733-1737
Author(s):  
Chang Xin Xiong ◽  
Yi Zhi Yan
Keyword(s):  
Wave Equation ◽  
Physical Properties ◽  
Seismic Response ◽  
Pressure Wave ◽  
Solid Medium ◽  
Response Magnitude ◽  
Physical Parameters ◽  
Sediment Thickness ◽  
Concrete Dam ◽  
Distribution Form

Studied a certain thickness layered sediment of different distribution form for the seismic response of a concrete dam, Based on pressure wave equation of saturated porous fluid-solid medium, the layers of sediment thickness is different, divided the layered sediment into three different distribution forms, the physical parameters of each layered sediment divided into the same and the different two situations, prediction the seismic response magnitude of concrete dam. Application of the method of a typical example shows the influence on the same physical properties different forms of response to the seismic response was not significant, the distribution of different forms of seismic response shows a significant effected. solid medium, the layers of sediment thickness is different, divided the layered sediment into three different distribution forms, the physical parameters of each layered sediment divided into the same and the different two situations, prediction the seismic response magnitude of concrete dam. Application of the method of a typical example shows the influence on the same physical properties different forms of response to the seismic response was not significant, the distribution of different forms of seismic response shows a significant effected.

Influence of effective parameters of non-orthogonal smeared crack approach in seismic response of concrete arch dams

2003 ◽  
Vol 30 (5) ◽  
pp. 890-901 ◽  
Author(s):  
Radin Espandar ◽  
Vahid Lotfi ◽  
Ghani Razaqpur
Keyword(s):  
Seismic Response ◽  
Nonlinear Dynamic Analysis ◽  
Arch Dam ◽  
Effective Parameters ◽  
Finite Element Program ◽  
Cracking Behavior ◽  
Arch Dams ◽  
Smeared Crack Approach ◽  
Element Program ◽  
Smeared Crack

A rigorous and relatively efficient algorithm based on the non-orthogonal smeared crack approach is coded in a special finite element program to study the seismic response of arch dams. The formulation is briefly presented. The 130 m high Shahid Rajaee arch dam in Iran subjected to the Friuli-Tolmezzo earthquake is selected to present a practical application of the technique. Under the same geometry and loading conditions, six nonlinear analyses with different parameters are performed, and the results are compared with each other and a linear case. The varied parameters include secant and elastic unloading–reloading options, threshold angle, and tensile strength of the material. It is concluded that the non-orthogonal smeared crack approach can redistribute the state of stresses and produces a more realistic profile of stresses in the dam. A drift in the crest displacements forms the prominent characteristics of the cracking behavior. The results also suggest that the dam can suffer significant cracking during a strong earthquake and still remain stable. Moreover, the influences of the mentioned parameters in the seismic response of the dam are comprehensively discussed.Key words: nonlinear dynamic analysis, concrete arch dam, smeared crack approach.

SYNTHESIS OF HYDROGEN IN ACOUSTOPLASMA DISCHARGE IN A LIQUID-PHASE STREAM

2019 ◽  
pp. 42-48 ◽  
Author(s):  
N. A. Bulychev
Keyword(s):  
Liquid Phase ◽  
Organic Compounds ◽  
Electrode Materials ◽  
Solid Phase ◽  
Plasma Discharge ◽  
Raw Material ◽  
Two Phase ◽  
Reduced Pressure ◽  
External Power Source ◽  
Phase Medium

In this paper, the plasma discharge in a high-pressure fluid stream in order to produce gaseous hydrogen was studied. Methods and equipment have been developed for the excitation of a plasma discharge in a stream of liquid medium. The fluid flow under excessive pressure is directed to a hydrodynamic emitter located at the reactor inlet where a supersonic two-phase vapor-liquid flow under reduced pressure is formed in the liquid due to the pressure drop and decrease in the flow enthalpy. Electrodes are located in the reactor where an electric field is created using an external power source (the strength of the field exceeds the breakdown threshold of this two-phase medium) leading to theinitiation of a low-temperature glow quasi-stationary plasma discharge.A theoretical estimation of the parameters of this type of discharge has been carried out. It is shown that the lowtemperature plasma initiated under the flow conditions of a liquid-phase medium in the discharge gap between the electrodes can effectively decompose the hydrogen-containing molecules of organic compounds in a liquid with the formation of gaseous products where the content of hydrogen is more than 90%. In the process simulation, theoretical calculations of the voltage and discharge current were also made which are in good agreement with the experimental data. The reaction unit used in the experiments was of a volume of 50 ml and reaction capacity appeared to be about 1.5 liters of hydrogen per minute when using a mixture of oxygen-containing organic compounds as a raw material. During their decomposition in plasma, solid-phase products are also formed in insignificant amounts: carbon nanoparticles and oxide nanoparticles of discharge electrode materials.

Some 1-substitution derivatives of 4-aryl-2,3-dihalogeno-1-naphthols

1984 ◽  
Vol 49 (1) ◽  
pp. 110-121 ◽  
Author(s):  
Jiří Křepelka ◽  
Drahuše Vlčková ◽  
Milan Mělka
Keyword(s):  
Thionyl Chloride ◽  
Oxirane Ring ◽  
Secondary Amines ◽  
Two Phase ◽  
Lytic Effect ◽  
Primary And Secondary Amines ◽  
Phase Medium ◽  
Chloro Derivatives ◽  
Derivatives Of

Alkylation of derivatives of 4-aryl-1-naphthols (I-V) by 2,3-epoxypropyl chloride in methanolic sodium hydroxide gave epoxy derivatives VI, VIII, IX, XI and XII, apart from products of cleavage of the oxirane ring, VII and X. Analogous alkylation of compounds I, IV and V by 2-(N,N-diethylamino)ethyl chloride hydrochloride in a two-phase medium afforded basic ethers XIII to XV. The cleavage of the oxirane ring in compound VI by the action of primary and secondary amines, piperidine and substituted piperazines led to compounds XVI-XXIV. Reaction of thionyl chloride with compounds XXI, XXII and XXIV gave chloro derivatives XXV-XXVII.Exposure of compound XXII to 4-methylbenzenesulfonyl chloride produced compound XXVIII, retaining the secondary alcoholic group. In an antineoplastic screening in vivo none of the compounds prepared had an appreciable activity. Compound XVII, being an analogue of propranolol, was used in the test of isoproterenolic tachycardia, and showed a beta-lytic effect comparable with that of propranol.

scholarly journals Thermocapillary effects in two-phase medium and applications to metal-silicate separation

2021 ◽  
pp. 106640
Author(s):  
Yanick Ricard ◽  
Stéphane Labrosse ◽  
Hidenori Terasaki ◽  
David Bercovici
Keyword(s):  
Two Phase ◽  
Metal Silicate ◽  
Phase Medium
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