scholarly journals Erratum: Seismic isolation effect of foamed concrete layer along the longitudinal direction of a mountainous tunnel

2019 ◽  
Vol 25 ◽  
pp. 226-226
Author(s):  
Can Li ◽  
Weizhong Chen
Keyword(s):  
Seismic Isolation ◽  
Longitudinal Direction ◽  
Isolation Effect ◽  
Concrete Layer ◽  
Foamed Concrete

scholarly journals A Study on Seismic Isolation of Shield Tunnel Using Quasi-Static Finite Element Method

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Can Li ◽  
Weizhong Chen ◽  
Wusheng Zhao ◽  
Takeyasu Suzuki ◽  
Yoshihiro Shishikura
Keyword(s):  
Finite Element ◽  
Shear Modulus ◽  
Seismic Isolation ◽  
Transverse Direction ◽  
Longitudinal Direction ◽  
Isolation Effect ◽  
Poisson's Ratio ◽  
Shield Tunnel ◽  
Isolation System ◽  
Isolation Layer

Using a quasi-static method based on an axisymmetric finite element model for seismic response analysis of seismically isolated tunnels, the seismic isolation effect of the isolation layer is studied, and the seismic isolation mechanism of the isolation layer is clarified. The results show that, along the longitudinal direction of the tunnel, the seismic isolation effect is mainly affected by the shear modulus of the isolation material. The smaller the shear modulus is, the more evident the seismic isolation effect is. This is due to the tunnel being isolated from deformation of its peripheral ground through shear deformation of the isolation layer. However, along the transverse direction of the tunnel, the seismic isolation effect is mainly affected by the shear modulus and Poisson’s ratio of the isolation material. When Poisson’s ratio is close to 0.5, a seismic isolation effect is not evident because the tunnel cannot be isolated from deformation of its peripheral ground through compression deformation of the isolation layer. Finally, a seismic isolation system comprising a shield tunnel in which flexible segments are arranged at both ends of an isolation layer is proposed, and it is proved that the seismic isolation system has significant seismic isolation effects both on the longitudinal direction and on the transverse direction.

scholarly journals On-Line Pseudo-Dynamic Response Test for Evaluating Seismic Isolation Effect by Tire Chips on Response of Saturated Sand Deposits

2010 ◽  
Vol 59 (1) ◽  
pp. 20-25
Author(s):  
Takashi KANEKO ◽  
Masayuki HYODO ◽  
Yukio NAKATA ◽  
Norimasa YOSHIMOTO ◽  
Hemanta HAZARIKA
Keyword(s):  
Dynamic Response ◽  
Seismic Isolation ◽  
Isolation Effect ◽  
Saturated Sand ◽  
Response Test ◽  
Tire Chips ◽  
On Line

scholarly journals Seismic Isolation Effect for Tunnel with Soft Isolation Layers.

1999 ◽  
pp. 27-36
Author(s):  
Sadao SHIMAMURA ◽  
Hiroshi KASAI ◽  
Masakazu HARUUMI
Keyword(s):  
Seismic Isolation ◽  
Isolation Effect

Application of Expansion Double Spherical Seismic Isolation Bearing in Seismic Design of Continuous Girder Bridges

2011 ◽  
Vol 243-249 ◽  
pp. 1928-1934 ◽  
Author(s):  
Tian Bo Peng ◽  
Zhen Nan Wang ◽  
Xun Tao Yu ◽  
Cheng Yu Yang
Keyword(s):  
Seismic Design ◽  
Seismic Isolation ◽  
Seismic Analysis ◽  
Design Method ◽  
Longitudinal Direction ◽  
Vertical Displacement ◽  
Girder Bridges ◽  
Earthquake Effect ◽  
Continuous Girder Bridge ◽  
Girder Bridge

The double spherical seismic isolation (DSSI for short) bearing has been adopted in seismic design of several important engineering projects since developed recently. It was used generally as fixed bearings in a continuous girder bridge in these projects, and only a few fixed piers, usually just one fixed pier would transmit the horizontal earthquake action to the foundation, which is uneconomical and results in the much larger seismic risk in the longitudinal direction of a continuous girder bridge than that in the transverse direction. In order to share the earthquake effect with all the piers and avoid relative vertical displacement among all the bearings under the normal traffic conditions, a new seismic design method of continuous girder bridges is introduced. The configuration and working mechanism of two kinds of DSSI bearings used to make the new seismic design possible are introduced. It’s shown that the method is preferable for the seismic design of continuous girder bridges by a numerical seismic analysis with a four-span continuous girder bridge.

Development of Defining Equations for the Mathematical Theory of Concrete Corrosion Processes

2020 ◽  
pp. 15-27
Keyword(s):  
Solid Phase ◽  
Longitudinal Direction ◽  
Technical Condition ◽  
Moving Boundaries ◽  
Chemical Transformations ◽  
Layer Depth ◽  
Dissolution Reaction ◽  
Concrete Layer ◽  
Physical And Chemical ◽  
Active Substances

The fundamental difference of the developed defining equations is that they consider the dual system of porosity and kinetic laws of physical and chemical transformations to describe individual stages of corrosion processes. The dual porosity system comprises through capillaries (pores) of the longitudinal direction and adjacent capillaries of the transverse direction. During the reagent mass transfer in through capillaries (pores) there takes place their transfer to transverse ones, in which we can observe the neutralization (dissolution) reaction of chemically active substances in solid phase with the formation of the moving boundaries. The binding and release rate in case of leaching are determined from the respective boundary value problems and are similar in structure. In defining equations, all parameters are reduced to two generalized ones. Their values for forecasting the technical condition of operating structures are to be determined on the basis of concentration distribution of the aggressive component in concrete layer depth in the above-specified structures.

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