A hybrid model formed by partitioning a soil~structure system into a near-field and a far-field has been successfully exploited in the analysis of three dimensional soil-structure interaction problems. The near field which consists of the structure and a finite region of soil around it is modelled by the finite element method. The far-field which accounts for the loss of energy due to stress waves travelling away from the foundation is modelled through continuous impedance functions. The main purpose of this investigation is to complement the previous research on three-dimensional hybrid modelling by employing the same tecp~ique to the two-dimensional case. To determine the two-dimensional frequency dependent impedance functions, a method of system identification is used to insure that the resulting hybrid model reproduces the known compliances of an infinite rigid strip on an elastic halfspace. These impedance functions have been employed to calculate the compliances of the strip for different Ria ratios. Good agreement between the computed and known compliances is shown.

H. D. McNiven

Papers

Evaluation of seismic design provisions for masonry in the United States