Plate Foundation Research Articles

Compliance of a rigid joint of a steel column of I-section on a rigid foundation

The article considers the compliance of a rigid assembly of a steel column of a typical I-section under the loads of an eccentric-compressive load with a random eccentricity. A simplified scheme of pinching a rigid hinge is considered as well as its detailed version in which the rigid part of the rod is elaborated as a basement, foundation plate, cross-arm and anchor bolts with plates. The authors carried out numerical studies of this site using a computer complex Abaqus 2017. Analysis of the results showed that the inclusion of compliance at a sufficiently accurate numerical simulation gives the same value for compressive forces. Thus, this node can be considered rigid, and the coefficient of buckling is almost equal to the theoretical value.

Buckling analysis of plates reinforced by Graphene platelet based on Halpin-Tsai and Reddy theories

In this paper, buckling analyses of composite plate reinforced by Graphen platelate (GPL) is studied. The Halphin- Tsai model is used for obtaining the effective material properties of nano composite plate. The nano composite plate is modeled by Third order shear deformation theory (TSDT). The elastic medium is simulated by Winkler model. Employing nonlinear strains-displacements, stress-strain, the energy equations of plate are obtained and using Hamilton's principal, the governing equations are derived. The governing equations are solved based on Navier method. The effect of GPL volume percent, geometrical parameters of plate and elastic foundation on the buckling load are investigated. Results showed that with increasing GPLs volume percent, the buckling load increases.

Two-dimensional generalized finite integral transform method for new analytic bending solutions of orthotropic rectangular thin foundation plates

In this paper, a two-dimensional generalized finite integral transform method is developed for new analytic bending solutions of orthotropic rectangular thin foundation plates. The vibrating beam functions are adopted as the integral kernels to construct the integral transform pairs. By imposing the transform to the governing equation, utilizing some inherent properties of the beam functions, the title problem is converted to that of solving a system of linear algebraic equations, by which the new analytic solutions are elegantly obtained in a straightforward way. Numerical examples validate the present method as well as the solutions yielded by satisfactory agreement with the literature and finite element analysis.

Determination of the Optimal Parameters of the Array Stabilized by the Spatial Structural Reinforced Elements

This article describes the stabilization method of structurally unstable and subsiding soils with spatial structural elements of the cement soil. There are shown the examples of creating spatial structures of various shapes. There is described the program for selecting the most optimal combinations of all gain parameters. On a real example, there is shown the proposed method of designing the strengthening of subsiding soils at the base of the plate foundation of a two-storey dormitory building.

Energy Method of Static Analysis of Stiffened Plates on Elastic Foundation

This paper is devoted to derive the calculating formula of the deformation and the internal force of stiffened plate on elastic foundation, which is beneficial for the engineering design. Nowadays, we generally use the finite element method to solve the deformations and internal forces of stiffened plates on elastic foundation under loads, which the calculate setting is complex and the amount of calculation is large. In this paper the calculating deformation formula of this construction on elastic foundation under loads is derived by means of energy method. Calculating the potential energy of the foundation plate, that of the foundation beams, that of the loads on the stiffened plate and that of the foundation reactions forces, separately, and substituting them into the minimum condition of total potential energy while the structure is equilibrium, the calculating deformation formulas of this construction is obtained. The internal forces of foundation plate can be obtained according to formulas of mechanics of elasticity. The internal forces of foundation beams can be obtained according to the differential relationships among the deformation, bending moment and shearing force of the beam. Using the formulas in this paper, the deformations and the internal forces of stiffened plate on elastic foundation can be calculated out easily. Comparing with the finite element method, the amount of computation can be reduced greatly by using these formulas in this paper.

Unbalance influence on the rotating assembly dynamics of a hydro

The dynamics of the rotating parts of a hydro is characterized by the dynamic interaction between the rotor, the stator and the working fluid in order to operate the hydro. The main factors influencing the dynamics of the rotating parts of a hydro are: rotor unbalance, unbalanced magnetic pull, shaft misalignment and hydraulic flow regime. Rotor unbalanced is one of the most common factors influencing the dynamic stability of the rotating parts of a hydro. The unbalanced is determined by: uneven distribution of rotating masses, displacement of parts in the rotor during rotation, inhomogeneity of rotor component materials, expansion of the rotor due to heating, and rising speed during the transient discharge of the load. The mechanical imbalance of a rotor can lead to important forces, responsible for the vibration of the machine, which ultimately leads to a shorter operating time. Even a low unbalance can lead, in the case of high speed machines, to major unbalance forces that cause significant damage to the equipment. The unbalance forces cause additional vibrations in the bearings as well as in the foundation plate. To avoid these vibrations, it is necessary in the first stage to balance the static rotor in the construction plant and then to a dynamic rotation balancing.

Construction of high-rise buildings in the Far East of Russia

The construction of high-rise buildings on plate foundation in geotechnical conditions of the Russian Far East is a complicated problem. In this respect foundation engineering becomes rather essential. In order to set a firm foundation it is necessary to take into account the pressure distribution at the structure base, in homogeneity of building deformation, which is due to collaborative geotechnical calculations complicated by a number of factors: actual over-placement of soils, the complex geometry of the building under construction, spatial work of the foundation ground with consideration for physical nonlinearity, the influence of the stiffness of the superstructure (reinforced concrete framing) upon the development of foundation deformations, foundation performance (the performance of the bed plate under the building and stairwells), the origination of internal forces in the superstructure with differential settlement. The solution of spatial problems regarding the mutual interaction between buildings and foundations with account of the factors mentioned above is fully achievable via the application of numerical modeling methodology. The work makes a review of the results of high-rise plate building numerical modeling in geotechnical conditions of the Russian Far East by way of the example of Khabarovsk city.

Design and Improvement of foundation soil for high-rise construction

The assessments were made in the current practice based on the design foundation of high-rise buildings in Moscow to find a method for improving the soil foundation. Many references showed that the current design was controlled by structural engineers. They commonly used the old methods of analysis, the first part was carried out for the design of the structure and architecture of high-rise building, the second part of the study was to explore the benefit of adopting the application of stone columns raft foundation design concept. A comparative study was made between the results of the 3-dimensional finite element (3D FEM) analysis in SCAD software. The results showed that the plate foundation of the building does not satisfy to carry the total load without some meaning of improvement. The 3D FEM by PLAXIS 3D showed that the used stone columns decreased the settlement because about 70-80% of the total building loads were carried by columns when the raft was placed in the stiff clay layer. The number of columns in the raft foundation can be significantly reduced, particularly if the soil had strong characteristics. The raft foundation settlement can be significantly reduced, particularly if the soil had strong characteristics.

Research on the application of wheel pile foundation for transmission lines

Under the action of low pressure, the wheel pile foundation bears most or even all the downward pressure. When the wheel pile foundation is subjected to uplift force, the uplift force is supported by the short pile, and the ring frame and the 4 flange mainly play the role of transfer pulling force, while the main bearing force is short and short pile. When the wheel pile foundation is subjected to horizontal forces, the horizontal force is mainly borne by the flange and the ring frame. Therefore, only downward pressure and horizontal force should be considered for the ring frame and flange, while uplift force should be considered for the design of thin and short piles. The basic design is simple and the transmission path is clear. The ring frame, flange and short pile of the wheel pile foundation are prefabricated. The foundation can take different prefabricated installation methods with the mechanized construction conditions. It can not only guarantee the quality of the concrete slab, but also speed up the construction speed of the foundation. By comparing with the economic technology of the plate foundation, it is found that under the same geological conditions, the use of wheel pile foundation can reduce the concrete earthwork and the increase of the load, the decrease of concrete is also increased, and the amount of steel is saved, and the economic benefit is remarkable.

Компьютерное моделирование конструкции плитного фундамента резервуара для нефти и нефтепродуктов с использованием арматуры из материалов с памятью

Компьютерное моделирование конструкции плитного фундамента резервуара для нефти и нефтепродуктов с использованием арматуры из материалов с памятью

Analysis of the effect of circulating pumps on the vibration of the SOLARIS synchrotron base plate

Advanced research equipment like the SOLARIS synchrotron requires specific working conditions. One of the major disturbances are vibrations of the synchrotron foundation plate, derived from internal equipment and external sources. The purpose of the present research was to identify the dominant sources and to analyze the wave propagation path. In basic research, a set of circulating pumps for cooling liquid was selected and under controlled conditions measurements were made. As a result of the analysis of the data obtained, was revealed an inability to which could affect the work of the synchrotron. The paper presents partial results and conclusions from the research conducted.

Analisis StrukturRumah Sakit Umum Intan Husada – Garut Bagian Rawat Inap

The construction of a building must of course be planned in accordance with the needs,which the building must have the criteria of safe, comfortable, economical, beautiful and inaccordance with the designation. Intan Husada Hospital Building Kab. Garut inpatient section wasbuilt to meet the needs of the community, especially District Tarogong Kidul generally Garut regencyin the inpatient care service. Building RSU Intan Husada Garut built 4 floors with most use ofreinforced concrete structures. Floor plates are set 25 Mpa (f'c) and 400 Mpa (fy) concrete. Forstructural parts in general the columns and beams are fixed with 25 Mpa concrete and 400 Mpa (fy)steel grade. For the foundation itself set by using foot plate foundation. Planning of reinforcedconcrete structure refers to Indonesian National Standard (SNI) SNI 03-2847-2002 on Procedure ofPlanning of Concrete Structure for Building Building. Structural Analysis with recognized softwaretools. The result of structure analysis in the form of moment, normal and shear is used to plot elementsof structure. From structural analysis that is done obtained comparison of calculation result ofstructural analysis with attached. Column analysis results with longitudinal reinforcement 19D22D10-180 while the longitudinal tu-straw 20D25 stirring D10-100. Beams of analysis results withlongitudinal reinforcement 2D13 and 9 D22 stirring D10-200 while the longitudinal reinforcingbattles 19D22 stirring D10-100. Sloof beam analysis with longitudinal reinforcement 4D22 D8-250while mounted longitudinal 6D22 stirring D10-100.

Free vibration analysis of thick viscoelastic composite plates on visco-Pasternak foundation using higher-order theory

Free vibration of laminated viscoelastic composite plates on Pasternak viscoelastic medium with simply supported edge conditions is investigated. The composite plate consists of linear viscoelastic polymeric matrix reinforced by transversely isotropic elastic fibers. Multi-cell micromechanical approach together with relaxation functions of bulk/shear moduli and Boltzmann superposition principle are adopted to establish time-dependent stiffness coefficients of laminates. The coupled integro-PDEs of motions are derived based on third-order shear deformation theory by Laplace transformation and Hamilton principle. Complex frequencies and closed form solutions for transient response are achieved by weighted residual method, iterative numerical algorithm and Fourier transform. To verify, the results are compared for thick elastic composite plates on Pasternak elastic foundation and thick viscoelastic composite sandwich plates without foundation that represent acceptable accuracy. By parametric study, effects of materials, lamination scheme, geometry and medium on dynamic characteristics are scrutinized.

Local radial basis function collocation method for bending analyses of quasicrystal plates

• Meshless formulations are developed for static and dynamic bending of QC plates. • The phonon-phason coupling effects are studied numerically. • The influence of elastic foundation and variable plate thickness is investigated. • The response of QC plates to impact loading is simulated. The local radial basis function collocation method (LRBFCM) is proposed for plate bending analysis in orthorhombic quasicrystals (QCs) under static and transient dynamic loads. Three common types of the plate bending problems are considered: (1) QC plates resting on Winkler foundation (2) QC plates with variable thickness and (3) QC plates under a transient dynamic load. According to the Reissner–Mindlin plate bending theory, there is allowed to simulate the behavior of the two excitations in QC plates, phonon and phason, by 2D strong formulations for the system of governing equations. The governing equations, which describe the phason displacements, are based on Agiasofitou and Lazar elastodynamic model. Numerical results demonstrate the effect of the elastic foundation, as well as plate thickness on the phonon and phason characteristics in this paper. For the transient dynamic analysis, the influence of the phason friction coefficients on the responses of QC plate to transient dynamic loads is also studied.

Vibration analysis of magneto-electro-elastic heterogeneous porous material plates resting on elastic foundations

This paper proposes a four-variable shear deformation refined plate theory for free vibration analysis of embedded smart plates made of porous magneto-electro-elastic functionally graded (MEE-FG) materials. Magneto-electro-elastic properties of FG plate are supposed to vary through the thickness direction and are estimated through the modified power-law rule in which the porosities with even and uneven type are approximated. The governing differential equations and boundary conditions of embedded porous FG plate under magneto-electrical field are derived through Hamilton's principle based on a four-variable tangential-exponential refined theory which avoids the use of shear correction factors. An analytical solution procedure is used to achieve the natural frequencies of embedded porous FG plate supposed to magneto-electrical field with various boundary condition. Influences of several important parameters such as material graduation exponent, porosity volume fraction, magnetic potential, electric voltage, various boundary conditions, elastic foundation parameters and plate side-to-thickness ratio on natural frequencies of embedded porous MEE-FG plate are investigated and discussed in detail. It is concluded that these parameters play significant roles on the dynamic behavior of porous MEE-FG plates resting on elastic foundation. Presented numerical results can serve as benchmarks for future analyses of MEE-FG plates with porosity phases.

A BEM/FEM formulation for the analysis of piles submitted to horizontal loads

In this paper a coupled Boundary Element Method (BEM)/Finite Element Method (FEM) formulation for the analysis of pile–soil interaction problems with the pile submitted to horizontal loading is presented. The soil is supposed to be a semi-infinite elastic, isotropic continuum and is modeled by the BEM and the piles are modeled by the finite element method. In the final system of equations the unknowns’ vector are the displacements and rotations at the nodes of the pile which, unlike other formulations, allows coupling with a foundation plate and a pile cap. Examples of single piles subjected to horizontal loading are analyzed with the presented formulation and their results compared with those from other formulations.

Analysis of multilayered composite plates resting on elastic foundations in thermal environment using a hyperbolic model

This paper is devoted to investigate the effect of hyperbolic thermal condition on the bending response of simply-supported shear-deformable multilayered composite plates resting on elastic foundations using a new hyperbolic model. Through this model, the shear stresses are devolved to zero at the top and bottom surfaces of the plate. The governing equations are based on the present hyperbolic model and include the plate–foundation interaction and thermal effect. The effects of temperature concentration, foundation parameters, transverse shear deformation, aspect ratio, side-to-thickness ratio on deflections and stresses are investigated. Some validation examples are presented to show the accracy of the present model comparing with the corresponding models in the literature.

Nonlinear vibration of functionally graded graphene-reinforced composite laminated plates in thermal environments

This paper deals with the large amplitude vibration of functionally graded graphene-reinforced composite laminated plates resting on an elastic foundation and in thermal environments. The temperature-dependent material properties of piece-wise functionally graded graphene-reinforced composites (FG-GRCs) are assumed to be graded in the thickness direction of a plate, and are estimated through a micromechanical model. Based on a higher-order shear deformation plate theory, the motion equations are developed with geometric nonlinearity taking the form of von Kármán strains. The plate–foundation interaction and thermal effects are also included. The motion equations are then solved by a two-step perturbation technique to determine the nonlinear frequencies of the FG-GRC laminated plates. The numerical illustrations concern the nonlinear vibration characteristics of FG-GRC laminated plates under different sets of thermal environmental conditions, from which results for uniformly distributed GRC laminated plates are obtained as comparators. The effects of distribution type of reinforcements, temperature variation, foundation stiffness and different in-plane boundary conditions are also investigated.

The Method Comparison of Anti-Floating of Reinforced Concrete Slab at Underground Business Street

It’s a good mean to develop underground business street. But at South China, usually the underground water level is higher, while the weight of structures is smaller, so it causes a prominent problem—anti-floating of structures. These cases of failure including both whole anti-floating and partial anti-floating are reported occasionally. To thoroughly solve the problem of anti-floating, the foundation design of underground street structure is particularly important. At present there are two kinds of foundation design scheme of the underground street. The First is raft foundation plus anti-floating anchors, and the second is independent foundation plus waterproof plates. In this paper, according to practical underground business street, two kinds of foundation design scheme are used to calculate the foundation respectively. Conclusion are drawn: by means of raft foundation, the quantity of bars at Column pier is smaller than that by means of independent foundation; the quantity of bars at raft is bigger than that by means of waterproof plates; the quantity of bars at waterproof plate is bigger gained by means of experience coefficient method than that by mean of JCCAD.

Bearing capacity of rectangular footings in uniform clay with deep embedment

This letter is concerned with the undrained bearing capacity of rectangular footings with various aspect ratios and embedment ratios in uniform clay. It covers thin plate foundations with low aspect ratios and high embedment depth with embedment ratio up to 150. The work is based on small strain finite element analysis (FEA). After verification of the FEA model against existing solutions of the bearing capacity factors of rectangular footings, a series of FEA results are obtained. Based on the FEA results, a simple formulation is proposed to calculate the bearing capacity factor for rectangle footing with different aspect ratio in any embedment depth, extending the existing solutions to cover a wider ranges of footing aspect ratios and embedment ratios.