scholarly journals Numerical Algorithm for Dynamic Impedance of Bridge Pile-Group Foundation and Its Validation

Algorithms ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 247
Author(s):  
Chenyu Wang ◽  
Hong Qiao ◽  
Yi Wang ◽  
Xianting Du
Keyword(s):  
Numerical Algorithm ◽  
Dynamic Performance ◽  
Pile Group ◽  
Solution Algorithm ◽  
The Finite Element Method ◽  
Artificial Boundary ◽  
Impedance Function ◽  
Dynamic Impedance ◽  
Impact Experiment

The characteristics of bridge pile-group foundation have a significant influence on the dynamic performance of the superstructure. Most of the existing analysis methods for the pile-group foundation impedance take the trait of strong specialty, which cannot be generalized in practical projects. Therefore, a project-oriented numerical solution algorithm is proposed to compute the dynamic impedance of bridge pile-group foundation. Based on the theory of viscous-spring artificial boundary, the derivation and solution of the impedance function are transferred to numerical modeling and harmonic analysis, which can be carried out through the finite element method. By taking a typical pile-group foundation as a case study, the results based on the algorithm are compared with those from existing literature. Moreover, an impact experiment of a real pile-group foundation was implemented, the results of which are also compared with those resulting from the proposed numerical algorithm. Both comparisons show that the proposed numerical algorithm satisfies engineering precision, thus showing good effectiveness in application.

scholarly journals Stability charts based on the finite element method for underground cavities in soft carbonate rocks: validation through case-study applications

2019 ◽  
Vol 19 (10) ◽  
pp. 2079-2095 ◽  
Author(s):  
Michele Perrotti ◽  
Piernicola Lollino ◽  
Nunzio Luciano Fazio ◽  
Mario Parise
Keyword(s):  
Finite Element ◽  
Safety Margin ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Geometrical Features ◽  
Overall Stability ◽  
Underground Cavities ◽  
The Stability ◽  
Rock Mechanical Properties

Abstract. The stability of man-made underground cavities in soft rocks interacting with overlying structures and infrastructures represents a challenging problem to be faced. Based upon the results of a large number of parametric two-dimensional (2-D) finite-element analyses of ideal cases of underground cavities, accounting for the variability both cave geometrical features and rock mechanical properties, specific charts have been recently proposed in the literature to assess at a preliminary stage the stability of the cavities. The purpose of the present paper is to validate the efficacy of the stability charts through the application to several case studies of underground cavities, considering both quarries collapsed in the past and quarries still stable. The stability graphs proposed by Perrotti et al. (2018) can be useful to evaluate, in a preliminary way, a safety margin for cavities that have not reached failure and to detect indications of predisposition to local or general instability phenomena. Alternatively, for sinkholes that already occurred, the graphs may be useful in identifying the conditions that led to the collapse, highlighting the importance of some structural elements (as pillars and internal walls) on the overall stability of the quarry system.

Research on the Reliability of Box for Gear Test Bed

2011 ◽  
Vol 121-126 ◽  
pp. 1744-1748
Author(s):  
Xiang Yang Jin ◽  
Tie Feng Zhang ◽  
Li Li Zhao ◽  
He Teng Wang ◽  
Xiang Yi Guan
Keyword(s):  
Power Flow ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Test Bed ◽  
Kinematics Simulation ◽  
Beveloid Gears ◽  
Overall Performance

To determine the efficiency, load-bearing capacity and fatigue life of beveloid gears with intersecting axes, we design a mechanical gear test bed with closed power flow. To test the quality of its structure and predict its overall performance, we establish a three-dimensional solid model for various components based on the design parameters and adopt the technology of virtual prototyping simulation to conduct kinematics simulation on it. Then observe and verify the interactive kinematic situation of each component. Moreover, the finite element method is also utilized to carry out structural mechanics and dynamics analysis on some key components. The results indicate that the test bed can achieve the desired functionality, and the static and dynamic performance of some key components can also satisfy us.

Development of Graphical Method of Pile Group Foundation Design

2016 ◽  
Vol 845 ◽  
pp. 94-99
Author(s):  
Noegroho Djarwanti ◽  
Raden Harya Dananjaya ◽  
Fauziah Prasetyaningrum
Keyword(s):  
Los Angeles ◽  
Construction Projects ◽  
Graphical Method ◽  
Pile Group ◽  
Foundation Design ◽  
Fast Estimation ◽  
Pile Cap ◽  
Single Piles ◽  
Simplified Analysis

In the construction projects, a pile group foundation is often utilized. The group of bored piles is usually installed relatively close to each other and joined at the top by a pile cap to hold up the loads. In other hand, a fast estimation of the groups of piles capacities are needed in the preliminary design and in other conditions of projects, such as a supervisor of projects want to estimate the capacities of the group of piles. The purpose of this research is to study the correlations of groups of piles efficiencies with the number of piles and to compare the groups of piles capacities with the single piles capacities. Furthermore, this study is aimed to make a fast estimation of groups of piles capacities using proposed graphical method.The piles efficiencies are calculated using several methods, such as Simplified Analysis, Converse-Labare [1][2], Los Angeles Group, Seiler - Keeney, Das, and Sayed - Baker. In order to calculate the groups of piles capacities, the capacities of single piles are needed. The singles piles capacities are taken from graphical method proposed by Djarwanti et al. (2015a and 2015b). Three graphical methods utilized are derived from the Briaud et al. (1985) , Reese and Wright (1977), and Reese O’Neill method. Moreover, the proposed graphical method is applied in the case study. The case study takes palace in Graha Indoland Condotel Inside Yogyakarta Construction Project.The pile efficiency graph is recommended for this research since the value of pile efficiency could be easily taken. The value of pile efficiency for Graha Indoland Condotel Inside using Simplified Analysis, Converse - Labare, Los Angeles Group, Seiler – Keeney, Das, and Sayed – Baker are 1,75; 0,89; 0,94; 0,99; 4,00; 1,56 respectively. Meanwhile the value of pile group capacity with the value of pile group efficiency more than 1, showed that the pile group capacity based on the efficiency is bigger than the one based on single down pattern.

Frontal Impact Analysis of an Interprovincial Bus Using the Finite Element Method: Case Study in Ecuador

2020 ◽  
pp. 312-320
Author(s):  
Luis Santos-Correa ◽  
Diego Pineda-Maigua ◽  
Fernando Ortega-Loza ◽  
Jhonatan Meza-Cartagena ◽  
Ignacio Abril-Naranjo ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Impact Analysis ◽  
Frontal Impact ◽  
The Finite Element Method ◽  
Element Method

The Research on Seismic Performance of Tower under Icing Condition

2014 ◽  
Vol 986-987 ◽  
pp. 677-680
Author(s):  
Yu Chen Tian ◽  
Wei Jian Xue ◽  
Ying Zhou ◽  
Lan Jiang
Keyword(s):  
Transmission Lines ◽  
Southwest China ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Seismic Action ◽  
The Finite Element Method ◽  
Three Dimensional Model ◽  
Deformation Law ◽  
Prone Area ◽  
Internal Forces

Southwest area of china is the zone of the transmission lines which often happens icing disaster. It is also an earthquake-prone area, also influenced by the interaction between ice and earthquake. This article uses the finite element method (fem), establishing three-dimensional model for steel towers in southwest china, to analyze the dynamic performance of the ice condition and the analysis of seismic action. The aim is to get internal forces for steel towers under the action of earthquake and deformation law along with the change of ice thickness.

scholarly journals A D-N Alternating Algorithm for Solving 3D Exterior Helmholtz Problems

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Qing Chen ◽  
Baoqing Liu ◽  
Qikui Du
Keyword(s):  
Domain Decomposition Method ◽  
Three Dimensional ◽  
Boundary Element Methods ◽  
The Finite Element Method ◽  
Natural Boundary ◽  
Artificial Boundary ◽  
Nonoverlapping Domain ◽  
Helmholtz Problem ◽  
Nonoverlapping Domain Decomposition ◽  
Dimensional Domain

The nonoverlapping domain decomposition method, which is based on the natural boundary reduction, is applied to solve the exterior Helmholtz problem over a three-dimensional domain. The basic idea is to introduce a spherical artificial boundary; the original unbounded domain is changed into a bounded subdomain and a typical unbounded region; then, a Dirichlet-Nuemann (D-N) alternating method is presented; the finite element method and natural boundary element methods are alternately applied to solve the problems in the bounded subdomain and the typical unbounded subdomain. The convergence of the D-N alternating algorithm and its discretization are studied. Some numerical experiments are presented to show the performance of this method.

scholarly journals DYNAMIC IMPEDANCE OF A LARGE SCALE PILE-GROUP

1993 ◽  
Vol 447 (0) ◽  
pp. 57-66
Author(s):  
Kiyoshi MASUDA ◽  
Kenji MIURA ◽  
Eiji KITAMURA ◽  
Yuji MIYAMOTO
Keyword(s):  
Large Scale ◽  
Pile Group ◽  
Dynamic Impedance
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