Soil Structure Interaction (SSI) in Bridge Analysis & Design

B.V. Nagesh - Principal Consultant, Nagesh Consultants, Bangalore

The process in which the response of soil influences the motion of the structure and motion of the structure influences the response of soil is termed as SSI.

Soil structure interaction (SSI) consists of interaction between soil and the structure built on it. It is primarily an exchange of mutual stresses. Most of the civil engineering structures involve some type of structural element with direct contact with soil. When external forces act on these systems, neither structural displacements nor soil displacements are independent of each other.