Sensitivity Study on Nonlinear Seismic Response of Offshore Jackets Due to Different Earthquake Events

Author(s):  
Mehrdad Kimiaei

Earthquake design of offshore platforms is one of the main parts in offshore platforms design on which seismic soil pile structure interaction could be the main concern. In seismically active areas, it is often necessary to perform a dynamic analysis that accounts for nonlinear pile soil structure interaction effects. Based on a previously developed numerical BNWF-FE model for nonlinear seismic response of offshore platforms, in this paper, sensitivity of seismic response of an existing sample offshore platform to different earthquake events (with different duration and different frequency contents) together with the sensitivity of the results to the model main parameters are investigated.

2011 ◽  
Vol 255-260 ◽  
pp. 1167-1170
Author(s):  
Feng Miao ◽  
Wang Bo ◽  
Guan Ping

Based on scheme of Dalian gulf cross-sea bridge, in this paper, a 3-dimensional FE model for Self-anchored cable-stayed suspension bridge is established with finite element program and pile-soil-structure interaction is simulated by use of the equivalent embed fixation model. Based on the FE model, model analysis is carried out and the effects of pile-soil-structure interaction on dynamic behavior of long-span self-anchored cable-stayed suspension bridge are specially studied. The seismic response analysis result considering that pile-soil-structure interaction was compared with that of without considering such interaction. The analysis result show that interaction extend the nature period of structure, has the greatest impact to the first vibration mode; meanwhile, enlarged longitudinal displacement and moment of stiffening beam in middle of main span, longitudinal displacement on top of tower and axial force at bottom, but reduced the moment of tower at bottom. The research results provide some theoretical foundation to composite structure system.


2011 ◽  
Vol 63-64 ◽  
pp. 421-424
Author(s):  
Miao Feng ◽  
Guan Ping ◽  
Wang Bo

Based on scheme of Dalian gulf cross-sea bridge, in this paper, a 3-dimensional FE model for Self-anchored cable-stayed suspension bridge is established with finite element program and pile-soil-structure interaction is simulated by use of the equivalent embed fixation model. Based on the FE model, model analysis is carried out and the effects of pile-soil-structure interaction on dynamic behavior of long-span self-anchored cable-stayed suspension bridge are specially studied. The seismic response analysis result considering that pile-soil-structure interaction was compared with that of without considering such interaction. The analysis result show that interaction reduced horizontal displacement in middle span of stiffening beam and top of tower, horizontal moment not only at bottom of tower, but also assistant piers. The research results provide some theoretical foundation to composite structure system.


2014 ◽  
Vol 6 (2) ◽  
pp. 43-61 ◽  
Author(s):  
Shehata E. Abdel Raheem ◽  
Mohamed M. Ahmed ◽  
Tarek M. A. Alazrak

Recent studies show that the effects of Soil Structure Interaction (SSI) may be detrimental to the seismic response of structure and neglecting SSI in analysis may lead to un-conservative design. Despite this, the conventional design procedure usually involves assumption of fixity at the base of foundation neglecting the flexibility of the foundation, the compressibility of soil mass and consequently the effect of foundation settlement on further redistribution of bending moment and shear force demands. The effects of SSI are analyzed for typical multi-story building resting on raft foundation. Three methods of analysis are used for seismic demands evaluation of the target moment resistant frame buildings: equivalent static load (ESL); response spectrum (RS) methods and nonlinear time history (TH) analysis with suit of nine time history records. Three-dimensional Finite Element (FE) model is constructed to analyze the effects of different soil conditions and number of stories on the vibration characteristics and seismic response demands of building structures. Numerical results obtained using soil structure interaction model conditions are compared to those corresponding to fixed-base support conditions. The peak responses of story shear, story moment, story displacement, story drift, moments at beam ends, as well as force of inner columns are analyzed.


2011 ◽  
Vol 243-249 ◽  
pp. 1798-1802
Author(s):  
Feng Miao ◽  
Guan Ping ◽  
Wang Bo

Based on scheme of Dalian gulf cross-sea bridge, in this paper, a 3-dimensional FE model for Self-anchored cable-stayed suspension bridge is established with finite element program and pile-soil-structure interaction is simulated by use of the equivalent embed fixation model. Based on the FE model, model analysis is carried out and the effects of pile-soil-structure interaction on dynamic behavior of long-span self-anchored cable-stayed suspension bridge are specially studied. Under vertical excitation, the seismic response analysis result considering that pile-soil-structure interaction was compared with that of without considering such interaction. The analysis result show that interaction reduced longitudinal displacement of stiffening beam in middle of main span and tower at bottom, moment at bottom of tower and auxiliary pier pile, but enlarged the moment of conjoining section between steel and steel beam. The research results provide some theoretical foundation to composite structure system.


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