Papers by Keyword: Soil-Structure Interaction (SSI)

Abstract: The plate-chair type retaining structure, which developed from h type anti-slide pile, has the characteristics of high stiffness and small deformations, and is suitable for subgrade retaining engineering on high slopes. The difficulty is that the landslide thrust distribution is not clear and the action of soil between the front and back row piles is not definite. First, a theoretical method of calculating the earth pressure acting on the structure is presented based on analyzing its carrying mechanism. Then an example is analyzed using the method. Finally, on the base of constructing a three-dimensional numerical simulation model of soil-structure interaction using ABAQUS, a validation and comparison between the theoretical calculation and numerical simulation is carried out. The result shows that the method is simple, safer, suitable for designing and can be used in the similar engineering.

Abstract: In the paper the experiment results of deformation in foundation slab segment in interaction with subsoil are presented. Pilot measurement is carried out on original subsoil with characteristics which were tested in cooperation with geotechnics specialists. Concrete precast slab with square dimensions 500 mm and with thickness 48 mm made of plain concrete is exposed to vertical load. The tests results are compared with bending moments and deformations analysed according to subsoil models given in Eurocodes using FEM analysis.

Abstract: Stress strain analysis of elastic halfspace by means of Gauss numerical integration and Jacobean of transformation is presented. The arbitrary shape and general course of the loaded area in nodal points is allowed by use of 4-and 8-node isoparametric elements, numerical integration and Jacobean transformation. Results of numerical examples are compared with other solutions.

Abstract: The paper presents changes of natural frequencies of industrial steel hall due to simplifications or changes of numerical model. Firstly, the natural frequencies were calculated for basic Variant A of the numerical model of the steel hall which consisted of the main frames, footings, roof purlins and girts. In this Variant columns were fixed at bases, both purlins and girts were rigidly connected to main frames and designed as continuous beams. Then, in Variant B of the model columns were pinned at bases. Next, in Variant C different types of connections (semi-flexible joints) of roof purlins and girts with the main frame were implemented. Finally, in Variant D, soil-structure interaction was taken into consideration. The calculations of the dynamic characteristics of four abovementioned Variants of the numerical model of the hall showed that simplifications or changes of some details of the structure could result in significant errors in values of natural frequencies.

Abstract: Taking the Sifang Bridge in Yunnan Province in China as an example, this paper analysis the influences of soil-structure interaction on seismic response of extradosed cable-stayed bridge with response spectrum method. The results show that extradosed cable-stayed bridge has a shorter nature period than cable-stayed bridge, and torsional vibration mode does not happen in the first few modes as the beam has a bigger stiffness. The displacement of the structure will be underestimated if the soil-structure interaction is ignored while the design of some parts is conservative.

Abstract: Structure would be in different extent of translational-torsional coupling due to the inconsistent of mass center and stiffness center which caused by the irregularity of floor mass and stiffness distribution. At present, the research on seismic response of the eccentric structure was not perfect, especially the translational-torsional coupling response considering soil-structure interaction. This paper briefly reviewed the research status on the lateral-torsional coupling considering soil structure interaction effect and point out several problems existing currently in the field in order to make necessary preparations for analyzing seismic response of eccentric structure more in-depth.

Abstract: To increase the computation efficiency of the three-dimensional nonlinear dynamic analysis of soil-structure, the liner-nonlinear mixed constrained mode synthesis method was put forward according to the characteristic that the structure owns local plastic region, which is appropriate for both nonlinear substructure and multi linear substructures with boundary coupling. Divided the whole system into linear substructure and nonlinear substructure, this method reduced the freedom degree of linear substructure according to the potential energy criterion and finally synthesized them with the nonlinear substructure, thus obtaining the dynamic response of nonlinear system. The accuracy and effectiveness of this method were proved by further applying this method in the three-dimensional dynamic analysis example of soil-high building interaction system to carry out dynamic time-history analyses under the effect of multi-groups earthquake incentives respectively for two different boundary conditions of soil mass. Finally, several groups of numerical experimentations were conducted based on the various different values of nonlinear soil mass region, and the result indicated that as far as the example of this paper was concerned, it can obtain satisfiable computation result when the range of nonlinear soil mass region was 3 times of the horizontal size of upper structure, which further demonstrated the effectiveness of the method proposed in this paper.

Abstract: The aim of this paper is to develop an active structural control scheme to control wind turbine nacelle/tower out-of-plane vibration. An active tuned mass damper (ATMD) is designed an placed inside the turbine nacelle. An EulerLagrangian wind turbine model based on energy formulation is developed for this purpose, which considers the structural dynamics of the system and the interaction between in-plane and out-of-plane vibrations. Also, the interaction between the blades and the tower including the ATMD is considered. The wind turbine is subjected to gravity and turbulent aerodynamic loadings. A three-dimensional (3D) model of a wind turbine foundation is designed and analysed in the finite element geotechnical code PLAXIS. The rotation of the foundation is measured and used to calculate a rotational spring constant for use in wind turbine models to describe the soil-structure interaction (SSI) between the wind turbine foundation and the underlying soil medium. Damage is induced in the soil medium by a loss in foundation stiffness. The active control scheme is shown to reduce nacelle/tower vibration when damage occurs.

Abstract: In case of constructions placed on subsoil, it is necessary to create a rigidity matrix for the element subsoil. That rigidity matrix should be then added up in respective positions with the rigidity matrix of an element. To clarify the proposed model of the subsoil, a method is derived for determination of vertical subsoil stress analysis under any shape of a slab construction by means of numerical integration and theory of isoparametric elements using the Jacobian transformation. This approach is rather original and represents the key contribution of this work in interaction solutions. Using the proposed approach, the method can be employed for any shape of a finite element.

Abstract: As an effective way of passive damping, isolation technology has been widely used in all types of building structures. Currently, for its theoretical analysis, it usually follows the rigid foundation assumption and ignores soil-structure interaction, which results in calculation results distortion in conducting seismic response analysis. In this paper, three-dimensional finite element method is used to establish finite element analysis model of large chassis single-tower base isolation structure which considers and do not consider soil-structure interaction. The calculation results show that: after considering soil-structure interaction, the dynamic characteristics of the isolation structure, and seismic response are subject to varying degrees of impact.