scholarly journals Seismic Response Characteristics of Stabilizing Pile Based on Elastic-Plastic Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Honglue Qu ◽  
Ying Liu ◽  
Hao Luo ◽  
Huanguo Hu ◽  
Qindi Hu
Keyword(s):  
Plastic Zone ◽  
Seismic Response ◽  
Ground Motion ◽  
Seismic Design ◽  
Design Parameters ◽  
Plastic State ◽  
Elastic Plastic ◽  
Stabilizing Pile ◽  
Response Characteristics ◽  
Plastic Analysis

Stabilizing pile is widely used in the landslide controlling projects and shows excellent seismic performance under the action of earthquake. Therefore, in order to improve seismic design theory, it is of importance to study the seismic response characteristics of stabilizing pile based on elastic-plastic analysis. In view of this, elastic-plastic constitutive model was established to deduce the plastic zone of stabilizing pile. Based on elastic-plastic analysis, the seismic response characteristics and the influence of different section sizes, material strengths, and peak ground motion acceleration (PGA) were analyzed by ANSYS 3D. Resultantly, the elastic-plastic fourth-order tensor Cijklep was deduced, which can be used to calculate plastic strain of stabilizing pile under loading. Compared with Chinese code, the material of stabilizing pile working with elastic-plastic state will be decreased under the same section size and the same property. Furthermore, stabilizing pile is in the elastic stage at the beginning under the action of earthquake. With the increase of ground motion time, the section starts to exhibit elastic-plastic state and then the plastic zone expands gradually. Finally, the plastic zone runs through the whole section, resulting in the performance loss of the pile. In addition, under the different design parameters, pile shows different seismic response characteristics; namely, changing these parameters reasonably can improve the seismic design.

scholarly journals Multi-angle and nonuniform ground motions on cable-stayed bridges

2021 ◽  
pp. 875529302110513
Author(s):  
Eleftheria Efthymiou ◽  
Alfredo Camara
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Seismic Waves ◽  
Incidence Angle ◽  
Design Parameters ◽  
System Configuration ◽  
Cable System ◽  
Parametric Problem ◽  
Wide Range ◽  
Cable Stayed Bridges

The definition of the spatial variability of the ground motion (SVGM) is a complex and multi-parametric problem. Its effect on the seismic response of cable-stayed bridges is important, yet not entirely understood to date. This work examines the effect of the SVGM on the seismic response of cable-stayed bridges by means of the time delay of the ground motion at different supports, the loss of coherency of the seismic waves, and the incidence angle of the seismic waves. The focus herein is the effect of the SVGM on cable-stayed bridges with various configurations in terms of their length and of design parameters such as the pylon shape and the pylon–cable system configuration. The aim of this article is to provide general conclusions that are applicable to a wide range of canonical cable-stayed bridges and to contribute to the ongoing effort to interpret and predict the effect of the SVGM in long structures. This work shows that the effect of the SVGM on the seismic response of cable-stayed bridges varies depending on the pylon shape, height, and section dimensions; on the cable-system configuration; and on the response quantity of interest. Furthermore, the earthquake incidence angle defines whether the SVGM is important to the seismic response of the cable-stayed bridges. It is also confirmed that the SVGM excites vibration modes of the bridges that do not contribute to their seismic response when identical support motion is considered.

scholarly journals Seismic Response Analysis and Control of Frame Structures with Soft First Storey under Near-Fault Ground Motions

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Chunyang Liu ◽  
Peng Sun ◽  
Ruofan Shi
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Seismic Performance ◽  
Frame Structures ◽  
Response Analysis ◽  
Main Structure ◽  
Response Characteristics ◽  
Near Fault ◽  
Buckling Restrained Brace ◽  
Near Fault Ground Motion

This paper proposes two kinds of arrangements of buckling-restrained brace dampers to strengthen soft-first-storey structures locally. Two types of near-fault ground motion, with and without pulse, were selected for a study of the seismic response characteristics of soft-first-storey structures with and without buckling-restrained brace dampers, and the effects of different bracing arrangements on improving the seismic performance of soft-first-storey structures were recognized. The results show that, compared with pulse-free ground motion, near-fault pulsed ground motion results in a more severe seismic response in soft-first-storey frame structures, leading to more serious and rapid destruction of the main structure. Buckling-restrained brace dampers have an obvious energy dissipation effect, play a better role in protecting the main structure, and have good practicality. Compared with structures in which the buckling-restrained brace dampers are arranged only on the bottommost layer, the bottom-four-layer-support structure is more advantageous in terms of seismic performance.

scholarly journals A New Unified Solution for Circular Tunnels Based on Generalized SMP Criterion considering the Strain Softening and Dilatancy

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Qifeng Guo ◽  
Jiliang Pan ◽  
Xinghui Wu ◽  
Xun Xi ◽  
Meifeng Cai
Keyword(s):  
Internal Friction ◽  
Plastic Zone ◽  
Strain Softening ◽  
Friction Angle ◽  
Surrounding Rock ◽  
Internal Friction Angle ◽  
Plastic State ◽  
Circular Tunnel ◽  
Dilatancy Angle ◽  
Elastic Plastic

According to the strain-softening characteristics of rock mass, an ideal elastic strain-softening model is developed, and the surrounding rock of tunnels is subdivided into the plastic broken zone, plastic strain-softening zone, and elastic zone. Based on the generalized spatially mobilized plane criterion, an elastic-plastic analytical solution of a circular tunnel is derived. The effects of intermediate principal stress, strain softening, and dilatancy are considered in the unified solution. The stress, displacement, and plastic zone radius of surrounding rock based on the SMP criterion are compared with those based on the Mohr–Coulomb criterion. Furthermore, the effects of parameters such as the softening modulus, dilatancy angle, and internal friction angle on the deformation and stress of tunnels are discussed. It has been found that the larger the dilatancy angle is, the larger the plastic zone displacement and the radius of the broken zone are. The larger the internal friction angle, the smaller the sizes of the plastic zone, the strain-softening zone, and the broken zone are. The deformation of surrounding rock in the broken zone is more sensitive to the internal friction angle than that in the strain-softening zone. The unified solution based on the SMP criterion provides a well understanding for the elastic-plastic state of tunnels, which can be the guidance for tunnel excavations and support designs.

The Effect of Site Condition on Ground Motion in Gansu Province during the Wenchun Ms8.0 Earthquake

2012 ◽  
Vol 594-597 ◽  
pp. 1658-1667
Author(s):  
Zhi Jian Wu ◽  
Lan Min Wang ◽  
Ping Wang ◽  
Hang Shi ◽  
Tuo Chen
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Seismic Design ◽  
Site Effects ◽  
Strong Motion ◽  
Gansu Province ◽  
Response Analysis ◽  
Site Condition ◽  
Seismic Response Analysis ◽  
Ground Acceleration

Based on mobile strong motion array observation, borehole exploration and site seismic response analysis, the site effects of mountainous topography in southeastern Gansu and the topography of loess tableland on ground motion were investigated in details. The analysis on acceleration records of aftershocks showed that the peak ground acceleration at top of the mountain is nearly 2 times of that at the foot of it. The seismic response analysis of sites shows that the loess tableland may amplify PGA by 1.44-2.0 times. Therefore, site effects of mountains and loess topography on ground motion should been taken account into seismic design.

Study on Piping Response Under Multiple Excitation Validation for Elastic-Plastic Analysis of Piping

2014 ◽  
Author(s):  
Satoru Kai ◽  
Tomoyoshi Watakabe ◽  
Naoaki Kaneko ◽  
Kunihiro Tochiki ◽  
Makoto Moriizumi ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Seismic Response ◽  
Nuclear Power ◽  
Time History ◽  
Large Earthquake ◽  
Response Analysis ◽  
Analysis Method ◽  
Elastic Plastic ◽  
History Analysis ◽  
Plastic Analysis

Piping in a nuclear power plant is usually laid across several floors of a single building or adjacent buildings, and is supported at many points. As the piping is excited by a large earthquake through multiple supporting points, seismic response analysis by multiple excitations within the range of plastic deformation of piping material is necessary to obtain the precise seismic response of the piping. The verification of the dynamic analysis method of piping under an elastic domain, which is excited by multiple seismic inputs, was performed in our study last year and the correspondence of a piping response between an analysis and an experiment have been confirmed [17][18]. However, few experiments under plastic deformation conditions have been performed to verify the validity of multiple excitation analysis under a plastic deformation range. To obtain better understanding of the behavior of piping under a large seismic input, it is important to investigate the seismic response by multiple excitations and to verify the validity of the analytical method by multiple excitation experiments. This paper reports the validation results of the seismic elastic-plastic time history analysis of piping compared with the results of the shaking test of a 3-dimensional piping model under a plastic deformation range using triple uni-axial shake table. Three directional strains from the analysis and the experiments were compared in order to validate the analysis method. As a result, it is confirmed that the elastic-plastic analysis by time history excitation shows good agreement with the test results.

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