Loading...

Probabilistic Identification of Soil-foundation Impedance Function Using Kalman Filter

Jabini, Amin | 2018

661 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 51101 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Mahsouli, Mojtaba; Ghahari, Farid
  7. Abstract:
  8. This paper puts forward a probabilistic approach for simultaneous identification of the dynamic stiffnesses of the soil-foundation and the foundation input motion of soil-structure systems from sparsely-measured structural responses. The soil-structure system in this approach is represented by a shear building resting on sway- and rocking-representative springs and dashpots. The proposed approach employs unknown-input extended Kalman filtering in time domain. This method is built upon Bayesian updating and accounts for two major sources of uncertainty in the problem: the process noise that account for the modeling errors and the measurement noise. In the proposed method, the state vector of the system is augmented by unknown parameters of the soil-structure system, including the soil-foundation representative springs and dashpots. In each time step, a threefold procedure is carried out. First, the current states of the system are predicted by solving the equation of motion in which the posterior estimates of the unknown parameters and the input of the previous time step are employed. Second, the input of the current time step is estimated using an unbiased, minimum-variance estimator. Third, the current states and the parameters are updated to obtain a posterior estimate of the parameters at the current time step. This iterative process of prediction and updating is repeated for the full duration of the excitation. The end results are the mean vector and the covariance matrix of the unknowns, including the soil-structure parameters and the foundation input motion. Such results have direct applications in risk and reliability analysis of flexiblebase structures and rapid damage detection of a building portfolio following an earthquake
  9. Keywords:
  10. Impedance Function ; Extended Kalman Filter ; System Identification ; Bayesian Updating ; Soil-Structure Interaction ; Blind Identification

 Digital Object List

 Bookmark

No TOC