Finite-Infinite Element Dynamic Analysis of Pile-Soil-Structure System Considering the Change of Groundwater Level

2011 ◽  
Vol 250-253 ◽  
pp. 2291-2295
Author(s):  
Wei Hu ◽  
Guang Fan Li ◽  
Juan Du
Keyword(s):  
Dynamic Characteristics ◽  
Groundwater Level ◽  
Soil Structure ◽  
Horizontal Displacement ◽  
Element Model ◽  
Geological Condition ◽  
Shearing Stress ◽  
Structural Dynamic ◽  
Structure System ◽  
Infinite Element

The rise of groundwater level can reduce soil’s effective stress and destroy it’s structure. As a result, the dynamic characteristics of pile-soil-structure system will be changed remarkably. In this paper, a structural dynamic model was used for saturated loess, and the finite-infinite element model of pile-soil-structure system was established to study the groundwater level’s influence on the system’s dynamic characteristics, which included the distributions of pile section’s shearing stress, horizontal displacement and acceleration. The results indicated that, the height of groundwater level did not change the distribution shapes of shearing stress, horizontal acceleration, but had effect on their values. To the top section’s shearing stress and horizontal displacement, there almost had a same dividing groundwater level. When groundwater level was higher than that one, the shearing stress and horizontal displacement were increasing with the rising of groundwater level, but the regulations were just opposite when groundwater level under that height. The study also shown that, to a determinate geological condition and pile foundation, there has a dividing groundwater level, and which is also the most secure level to the pile-soil-structure system. The conclusion can give theoretic instruction for the safety evaluation of pile-soil-structure system around water area.

scholarly journals Comparison of Dynamic Characteristics between Small and Super-Large Diameter Cross-River Twin Tunnels under Train Vibration

2021 ◽  
Vol 11 (16) ◽  
pp. 7577
Author(s):  
Lin Wu ◽  
Xiedong Zhang ◽  
Wei Wang ◽  
Xiancong Meng ◽  
Hong Guo
Keyword(s):  
Dynamic Characteristics ◽  
Large Diameter ◽  
Horizontal Displacement ◽  
Element Model ◽  
Vertical Displacement ◽  
Decisive Factor ◽  
Cross River ◽  
Static Responses ◽  
Train Vibration ◽  
Twin Tunnels

Train vibration from closely aligned adjacent tunnels could cause safety concerns, especially given the soaring size of the tunnel diameter. This paper established a two-dimensional discrete element model (DEM) of small (d = 6.2 m) and super-large (D = 15.2 m) diameter cross-river twin tunnels and discussed the dynamic characteristics of adjacent tunnels during the vibration of a train that runs through the tunnel at a speed of 120 km/h. Results in the D tunnel showed that the horizontal walls have the same horizontal displacement (DH) and the vertical walls have the same vertical displacement (DV). The stress state of the surroundings of the D tunnel is the decisive factor for DH, and the distance from the vibration point to the measurement point is the decisive factor for DV. Results in the comparison of the d and D tunnels showed that the D tunnel is more stable than the d tunnel with respect to two aspects: the time the tunnel reaches the equilibrium state and the vibration amplitude of the structure’s dynamic and static responses. The dynamic characteristic of the d and D tunnel is significantly different. This research is expected to guide the design and construction of large diameter twin tunnels.

Dynamic Performance Analysis for a Butterfly-Shaped Arch Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 74-78
Author(s):  
Hai Yun Huang ◽  
Xiang Rong Yuan ◽  
Ka Hong Cai
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Element Model ◽  
Loading Test ◽  
Structural Dynamic ◽  
Arch Bridge ◽  
Calculation Results ◽  
Dynamic Performance Analysis

The dynamic characteristics are not only the important indexes for evaluating the bridge structural rigidity, but also the principal parameters for structural dynamic analysis and earthquake resistant analysis. In this paper, a three dimensional solid finite element model for a butterfly-shape arch bridge in Zhongshan city was established to analyze the dynamic characteristics. By comparison the numerical calculation results with measured results of the dynamic loading test, an analysis and evaluation of the dynamic performance of this new type spatial arch bridge was made, and can serve as reference to the dynamic analysis and seismic design of similar bridges.

The Analysis of Long Spiral Drilling Hole’s Deformation with Finite Element

2010 ◽  
Vol 168-170 ◽  
pp. 206-210
Author(s):  
Xiu Shao Zhao ◽  
Lin Li Mo ◽  
Da Xin Geng
Keyword(s):  
Finite Element ◽  
Groundwater Level ◽  
High Strength ◽  
Horizontal Displacement ◽  
Element Model ◽  
Soil Strength ◽  
Drilling Depth ◽  
3D Finite Element ◽  
Spiral Blade ◽  
Main Factor

The long spiral CFG pile construction often causes crack while in saturated slit. 3D finite element model is carried out, and the deformation of drilling hole is analyzed. The deformation’s factors are emphtically discussed such as drilling depth, dumped-soil load, soil strength, groundwater level etc. The results show that uneven settlement and horizontal displacement are relatively small while silt has high strength. The reduced soil strength is the main factor of drilling holes’ deformation, which causes serious hole shrinkage and the soil is brought to surface with spiral blade, and then causes “excessive dumping” and soil cracking.

Prediction of the Structural Dynamic Behavior of High Speed Turning Machine Spindles

2014 ◽  
Vol 555 ◽  
pp. 567-574
Author(s):  
Constantin Dogariu ◽  
Doru Bardac
Keyword(s):  
Finite Element ◽  
Dynamic Behavior ◽  
Dynamic Characteristics ◽  
High Speed ◽  
3D Model ◽  
Element Model ◽  
Structural Dynamic ◽  
Spindle Bearing ◽  
Machine Spindle ◽  
Bearing System

This paper presents a method to investigate the dynamic behavior of a turning high-speed spindle system. The machine tool main spindle unit is focused on direct driven spindle units for high-speed and high performance cutting. This paper analyzes the static behavior for a turning machine spindle and presents some activities to improve the CAD model for such complex systems. The proposed models take into account the spindle with the bearing detailed system. The analysis was performed during the design activity and was based on Finite Elements Method. Starting from the 3D model, using FEM done by means of ANSYS analysis, structural dynamic behavior was evaluated. The aim of this paper is to develop a finite element model of the machine spindle system and use this method for design optimization. The 3D model was designed using the Solidworks CAD software. In order to obtain accurate dynamic characteristics of the spindle-bearing system during the design stage, the finite element model is simulated using dedicated software, and a method in which springs and damping units imitate bearing support. The proposed method can predict the regular pattern in which bearing stiffness and bearing span affect natural frequency and harmonic response. The research demonstrates that this method predicts the dynamic characteristics of the spindle-bearing system therefore it can be a reference for dynamic optimization design of spindle-bearing systems in turn-milling centers. The static analysis was presented in another paper. The thermal analysis will be presented in a future paper.

Character Analysis of Balance and Imbalance of Varying Rigidity of Rigid Pile Composite Foundation under Seismic Load

2014 ◽  
Vol 1065-1069 ◽  
pp. 19-22
Author(s):  
Zhen Feng Wang ◽  
Ke Sheng Ma
Keyword(s):  
Finite Element ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Element Model ◽  
Composite Foundation ◽  
Seismic Load ◽  
Seismic Loads ◽  
Element Analysis ◽  
Rigid Pile ◽  
Rigid Pile Composite Foundation

Based on ABAQUS finite element analysis software simulation, the finite element model for dynamic analysis of rigid pile composite foundation and superstructure interaction system is established, which selects the two kinds of models, by simulating the soil dynamic constitutive model, selecting appropriate artificial boundary.The influence of rigid pile composite foundation on balance and imbalance of varying rigidity is analyzed under seismic loads. The result shows that the maximum bending moment and the horizontal displacement of the long pile is much greater than that of the short pile under seismic loads, the long pile of bending moment is larger in the position of stiffness change. By constrast, under the same economic condition, the aseismic performance of of rigid pile composite foundation on balance of varying rigidity is better than that of rigid pile composite foundation on imbalance of varying rigidity.

Dynamic Characteristics Analysis of Cable-Rib Tension Deployable Antenna

2016 ◽  
Author(s):  
Liu Ruiwei ◽  
Hongwei Guo ◽  
Zhang Qinghua ◽  
Rongqiang Liu ◽  
Tang Dewei
Keyword(s):  
Dynamic Characteristics ◽  
Structural Parameters ◽  
Element Model ◽  
Structure Design ◽  
Antenna Structure ◽  
Characteristics Analysis ◽  
New Type ◽  
Dynamic Characteristics Analysis ◽  
The Finite Element Model ◽  
Weight Dynamic

Balancing stiffness and weight is of substantial importance for antenna structure design. Conventional fold-rib antennas need sufficient weight to meet stiffness requirements. To address this issue, this paper proposes a new type of cable-rib tension deployable antenna that consists of six radial rib deployment mechanisms, numerous tensioned cables, and a mesh reflective surface. The primary innovation of this study is the application of numerous tensioned cables instead of metal materials to enhance the stiffness of the entire antenna while ensuring relatively less weight. Dynamic characteristics were analyzed to optimize the weight and stiffness of the antenna with the finite element model by subspace method. The first six orders of natural frequencies and corresponding vibration modes of the antenna structure are obtained. In addition, the effects of structural parameters on natural frequency are studied, and a method to improve the rigidity of the deployable antenna structure is proposed.

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