scholarly journals Seismic behavior of soil–pile–structure interaction with a modified Desai thin-layer interface element

2016 ◽  
Vol 8 (12) ◽  
pp. 168781401668094 ◽  
Author(s):  
Yu Miao ◽  
Erlei Yao ◽  
Hui Luo ◽  
Hongping Zhu
Keyword(s):  
Energy Dissipation ◽  
Thin Layer ◽  
Pile Foundation ◽  
Shear Force ◽  
Bending Moment ◽  
Interface Element ◽  
Hyperbolic Model ◽  
Seismic Load ◽  
Layer Interface ◽  
Contact Patterns

The Desai thin-layer interface element is widely utilized in the simulation of interaction between piles and soil under seismic load. Conventional seismic analysis using the interface element cannot simulate the process of energy dissipation because tangential damping is disregarded. In this study, Rayleigh damping is added to the interface element to simulate energy dissipation in a strong nonlinear contact behavior. A user-defined element program based on a modified Desai interface element is developed. A hyperbolic model is adopted to simulate normal and tangential interaction behaviors. Certain behavior pattern rules of the modified Desai element, such as bonding, slipping, gapping, and reclosing, are defined. A three-dimensional pile–soil–structure model with a modified Desai interface element is established to investigate the effect of contact patterns on the inner force responses of a superstructure and pile foundation to an earthquake. Numerical results show that the contact patterns significantly influence the shear force, bending moment, and torque of the superstructure, while axial force is unaffected. With regard to the pile foundation, shear force and bending moment are also significantly influenced.

scholarly journals Comparative Study Of Conventional Slab, Flat Slab And Grid Slab Using ETABS

2021 ◽  
Vol 1197 (1) ◽  
pp. 012020
Author(s):  
Abhijit K Sawwalakhe ◽  
Prabodh D Pachpor
Keyword(s):  
Shear Force ◽  
Bending Moment ◽  
Cost Effective ◽  
Seismic Load ◽  
Slab Thickness ◽  
Seismic Zone ◽  
Dead Load ◽  
Flat Slab ◽  
Story Drift ◽  
Heavy Loads

Abstract In today’s construction, the traditional slab is mostly supported by a beam, with a small slab thickness and a large beam depth, and the weight is carried from beam to column. The flat slab allows architects to place partition walls wherever they are needed. It is widely used because it reduces weight, speeds up building, and is cost effective. Similarly, since its inception, the conventional slab has provided benefits such as increased stiffness, increased weight carrying ability, as well as being safe and cost effective. Grid slabs are necessary where the span is greater, and grid beams are provided to lessen the spanning. Grid slabs reduce dead load due to voids and are appropriate for longer spans with heavy loads. The Grid slab is less expensive and provides superior vibration resistance. The project’s goal is to find the most cost-effective slab among standard slab, flat slab with drop, and grid slab. A G+5 Commercial multi-story structure with flat slab, conventional slab, and gird slab was investigated for characteristics such as storey displacement, shear force, bending moment, and storey drift in this study. There are a total of 18 structures examined. The performance and behaviour of all structures in India’s seismic zone III have been investigated with the application of dead load, live load and seismic load. The results of shear force, Bending Moment, story shear, story displacement, story drift and quantity of concrete and steel shows that the overall result values makes flat slab a suitable structure as compared to the conventional and grid slab.

scholarly journals Behaviour of the water tank staging with aluminum and steel X-plate damper

2020 ◽  
Vol 184 ◽  
pp. 01078
Author(s):  
G. Nirmala ◽  
Atulkumar Manchalwar
Keyword(s):  
Energy Dissipation ◽  
Nonlinear Dynamic ◽  
Shear Force ◽  
Dynamic Behaviour ◽  
Ground Motions ◽  
Nonlinear Dynamic Analysis ◽  
Bending Moment ◽  
Water Tank ◽  
Plate Steel ◽  
Water Tanks

Many water tanks are pull-down during post-earthquake due to failure of water tank staging and this occurs because of the dynamic behaviour of the water tank staging that leads to collapse of water tank. These are important elements during post-earthquake that must be in service. In this study to reduce the damage of water tank staging by installation of additional dissipation devices known as dampers made up of X-plate steel and aluminum and these are effective in reduction of damage of structures, gives the additional damping and additional stiffness to the structure. For this study water tank staging’s with different heights are modeled in SAP-2000 and performed nonlinear dynamic analysis under four real ground motions with and without damper. After the analysis the results obtained is, Displacement, shear force, amount of energy dissipation, maximum axial force and bending moment compared with and without damper and significantly reduced.

scholarly journals Seismic Interaction Characteristics of an Inclined Straight Alternating Pile Group-Soil in Liquefied Ground

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Desen Kong ◽  
Meixu Deng ◽  
Zhimin Zhao
Keyword(s):  
Pore Pressure ◽  
Pile Foundation ◽  
Pressure Ratio ◽  
Bending Moment ◽  
Pile Group ◽  
Alternating Group ◽  
Seismic Load ◽  
Seismic Action ◽  
Maximum Value ◽  
Pile Cap

In this paper, the pile-soil interaction of a low-rise pile cap foundation of an inclined straight alternating pile on two or three layers of a soil liquefaction site under seismic load is studied. By inputting the 0.5 g El Centro seismic wave in FLAC3D, the pile-soil interaction rule of the pile foundation of the inclined and straight pile groups of the low-pile cap under seismic action is simulated. By analyzing the soil acceleration, the pore pressure ratio, the horizontal displacement of the pile body, the vertical displacement, and the pile body bending moment, the law of pile-soil interaction between the pile and soil when the lower part of the pile is embedded in the clay layer is studied, and the low-rise pile cap inclined straight alternating group pile foundation on the two-layer soil and the three-layer soil free field is compared and analyzed. The results show that, under seismic load, the maximum acceleration of soil mass in the two-layer soil and three-layer soil model is discrete, and the pore pressure ratio of sand soil increases from bottom to top. By analyzing the displacement and bending moment of pile body, the bending moment at the joint between the pile cap and the top of pile body is the largest and the most vulnerable to damage. The maximum value of pile displacement and bending moment in the three-layer soil is less than the maximum value of the two-layer soil, indicating that the pile group foundation in the three-layer soil free site model is safer.

Seismic Control of a Self-Anchored Suspension Bridge Using Fluid Viscous Dampers

2020 ◽  
pp. 2150025
Author(s):  
Dongming Feng ◽  
Jingquan Wang
Keyword(s):  
Energy Dissipation ◽  
Shear Force ◽  
Bending Moment ◽  
Suspension Bridge ◽  
Longitudinal Direction ◽  
Damping Coefficient ◽  
Suspension Bridges ◽  
Seismic Control ◽  
Fluid Viscous Dampers ◽  
Connection System

A self-anchored suspension bridge balances forces internally without external anchorage requirements, making it suitable for sites where anchorages would be difficult to construct. It often adopts either a full-floating or a semi-floating tower-girder connection system, which may result in large displacement responses along bridge longitudinal direction during earthquakes. This study investigated the efficacy of using the fluid viscous damper (FVD) for seismic control of a single-tower self-anchored suspension bridge. First, the energy dissipation behaviors of the FVD under sinusoidal excitations were studied. It revealed that besides the damper parameters (i.e. damping coefficient and velocity exponent) of an FVD itself, the energy dissipation capacity also relies on the characteristics of external excitations. Therefore, optimum damper parameters added to a structure should be determined on a case-by-case basis. Parametric study was then carried out on the prototype bridge, which indicated a tendency of decreasing the longitudinal deck/tower displacements and tower forces with increasing damping coefficient [Formula: see text] and decreasing velocity exponent [Formula: see text]. Compared with the linear FVD, the nonlinear FVD with a smaller velocity exponent can develop more rectangular force-displacement loops and thus achieve better energy dissipation performance. With selected optimum damper parameters (i.e. [Formula: see text][Formula: see text]kN[Formula: see text]m[Formula: see text][Formula: see text]s[Formula: see text] and [Formula: see text]) for the two FVDs added between the deck and the tower, the longitudinal deck and tower displacements could be reduced by 54%, while the peak bending moment and shear force at the tower base could be reduced by 30% and 19%, respectively. It is concluded that the nonlinear FVD can provide a simple and efficient solution to reduce displacement responses of self-anchored suspension bridges while simultaneously reducing the bending moment and shear force in the tower.

scholarly journals Effect of Bottom Geometry on the Natural Sloshing Motion of Water Inside Tanks: An Experimental Analysis

2021 ◽  
Vol 11 (2) ◽  
pp. 605
Author(s):  
Antonio Agresta ◽  
Nicola Cavalagli ◽  
Chiara Biscarini ◽  
Filippo Ubertini
Keyword(s):  
Energy Dissipation ◽  
Water Depth ◽  
Shear Force ◽  
Experimental Tests ◽  
Shear Load ◽  
Damping Properties ◽  
Base Shear ◽  
Structure Interaction ◽  
Sloshing Phenomenon ◽  
Key Aspects

The present work aims at understanding and modelling some key aspects of the sloshing phenomenon, related to the motion of water inside a container and its effects on the substructure. In particular, the attention is focused on the effects of bottom shapes (flat, sloped and circular) and water depth ratio on the natural sloshing frequencies and damping properties of the inner fluid. To this aim, a series of experimental tests has been carried out on tanks characterised by different bottom shapes installed over a sliding table equipped with a shear load cell for the measurement of the dynamic base shear force. The results are useful for optimising the geometric characteristics of the tank and the fluid mass in order to obtain enhanced energy dissipation performances by exploiting fluid–structure interaction effects.

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.

Comportement de pieux d'essais instrumentés sous charge horizontale

1993 ◽  
Vol 30 (1) ◽  
pp. 1-11
Author(s):  
R. Frank ◽  
H. Zervogiannis ◽  
S. Christoulas ◽  
V. Papadopoulos ◽  
N. Kalteziotis
Keyword(s):  
Pile Foundation ◽  
Bending Moment ◽  
Standard Penetration Test ◽  
American Petroleum Institute ◽  
Full Scale ◽  
Test Method ◽  
Cohesionless Soil ◽  
Penetration Test ◽  
Cohesionless Soils ◽  
Final Design

This paper describes the behaviour of two test piles (one bored and postgrouted and one simply bored, both 31.7 m long and 0.75 m in diameter) subjected to horizontal loads. These full-scale pile tests were carried out for the actual design of the pile foundation of a pier of the Evripos cable-stayed bridge. This bridge will link the Euboea Island to mainland Greece. The two piles have already been subjected to bearing capacity tests under axial loadings. The inclinometer measurements, taken during the present tests, yielded, in particular, the deformed shape of the piles as well as the bending moments. Conclusions could be drawn for the final design of the pile foundation with respect to horizontal loadings. Furthermore, various calculation methods using p–y reaction curves for cohesionless soils have been checked: the Ménard pressuremeter method, the method of the American Petroleum Institute recommendations, and the Standard penetration test method of Christoulas. These pile tests show that simple measurements, taken on construction sites, can yield interesting results on the actual behaviour of horizontally loaded piles. Key words : pile, horizontal loading, full-scale test, horizontal loads, bending moment, subgrade reaction modulus, p–y curve, cohesionless soil, Standard penetration test, pressuremeter test.

Imperialist Competitive Algorithm for Multiobjective Optimization of Ellipsoidal Head of Pressure Vessel

2011 ◽  
Vol 110-116 ◽  
pp. 3422-3428 ◽  
Author(s):  
Behzad Abdi ◽  
Hamid Mozafari ◽  
Ayob Amran ◽  
Roya Kohandel
Keyword(s):  
Genetic Algorithm ◽  
Pressure Vessel ◽  
Shear Force ◽  
Minimum Weight ◽  
Bending Moment ◽  
Imperialist Competitive Algorithm ◽  
Optimum Shape ◽  
Working Pressure ◽  
Competitive Algorithm ◽  
Bending Stresses

This work devoted to an ellipsoidal head of pressure vessel under internal pressure load. The analysis is aimed at finding an optimum weight of ellipsoidal head of pressure vessel due to maximum working pressure that ensures its full charge with stresses by using imperialist competitive algorithm and genetic algorithm. In head of pressure vessel the region of its joint with the cylindrical shell is loaded with shear force and bending moments. The load causes high bending stresses in the region of the joint. Therefore, imperialist competitive algorithm was used here to find the optimum shape of a head with minimum weight and maximum working pressure which the shear force and the bending moment moved toward zero. Two different size ellipsoidal head examples are selected and studied. The imperialist competitive algorithm results are compared with the genetic algorithm results.

Application of the Mode-Acceleration Technique to the Solution of the Moving Oscillator Problem

1999 ◽  
Author(s):  
Alexander V. Pesterev ◽  
Lawrence A. Bergman
Keyword(s):  
Shear Force ◽  
Series Representation ◽  
Bending Moment ◽  
Static Solution ◽  
Distributed Parameter ◽  
Distributed Parameter System ◽  
Parameter System ◽  
One Dimensional ◽  
Acceleration Technique ◽  
Moving Oscillator

Abstract The problem of calculating the dynamic response of a one-dimensional distributed parameter system excited by an oscillator traversing the system with an arbitrarily varying speed is investigated. An improved series representation for the solution is derived that takes into account the jump in the shear force at the point of the attachment of the oscillator, which makes it possible to efficiently calculate the distributed shear force and, where applicable, bending moment. The improvement is achieved through the introduction of the “quasi-static” solution, an approximation to the desired one, which makes it possible to apply to the moving oscillator problem the “mode-acceleration” technique conventionally used for acceleration of series in problems related to the steady-state vibration of distributed systems. Numerical results illustrating the efficiency of the method are presented.

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