Soil–Structure Interaction (SSI) for Building Structures

Name: Soil–Structure Interaction (SSI) for Building Structures
Rating: 5.0 (2 reviews)

Fundamentals and ETABS Applications

Created byShuvanjan Dahal

Last updated 11/2025

English

What you'll learn

Understand the fundamentals of soil-structure interaction
Use simplified FEMA and NIST procedures to estimate SSI effects
Translate soil properties into equivalent springs and dashpots for analysis
Model SSI in ETABS for buildings with raft foundations

Course content

4 sections • 20 lectures • 8h 42m total length

Introduction to Soil Structure Interaction27:03
Approaches to Soil-Structure Modeling: Direct and Substructure Approaches19:37

Understanding the Rule of Thumb Test for Inertial SSI Effects35:02
Assess inertial soil–structure interaction using the rule-of-thumb h' over Vst, combining building height, fundamental period, and shear-wave velocity to predict significant inertial effects.
Kinematic Interaction Effect in Soil Structure Interaction (Base Slab Averaging)35:58
Kinematic Interaction Effect in Soil Structure Interaction (Embedment Effects)44:22
Explore kinematic interaction effects in soil–structure interaction, focusing on embedment effects and how soil movement shapes the response of building structures.
Foundation and Soil Flexibility (Part-1)22:36
Understand foundation soil flexibility and effects on vibrations and earthquake response. Learn to estimate soil stiffness and foundation flexibility with vertical, horizontal, and rotational springs per ESCE 716 and 4117.
Foundation and Soil Flexibility (Part-2) - ETABS Discussion on Link Properties28:49
Explain foundation and soil flexibility in SSI using method 1, modeling vertical and rocking impedances. Demonstrate input of ETABS link properties, including kz, ksh, ky, and embedment factors.
Foundation and Soil Flexibility (Part-3) - Flexible Foundation and Flexible Soil36:09
Foundation and Soil Flexibility (Part-4) - Passive Pressure and Friction34:36
Explore method 3 for foundation and swale flexibility, modeling a flexible foundation with linear flexible swale, using uniform spring stiffness, and evaluating passive pressure and friction limits.
Period Lengthening Effect26:34
How to Model a Basement?14:42

Example Application (Building, Site and Ground Motion) - Part 116:04
Example Application (Building, Site and Ground Motion) - Part 28:01
Examine soil–structure interaction in an instrumented building by comparing foundation input motion and free field motion, highlighting kinematic interaction, PGA and PGV variations, and connected pile groups and grade beams.
Example Application (Assumptions, Shear Wave Velocity)23:24
Analyze the Sherman Oaks building SSI by integrating shallow and deep foundations, including mat foundations, grid beams, and friction piles, and use Vs and Zp to assess stiffness and damping.
Example Application (Calculation of Stiffness and Damping Coefficients)20:44
Calculate stiffness and damping for the soil–structure interaction model, deriving G and G naught from density and Vs, then obtain surface stiffness and eta from tables, noting a0 iterative update.
Example Application (Calculation of Stiffness and Damping Intensities)15:10
Example Application (Distribution of Springs to Foundation Nodes)21:20
Explains distributing horizontal and vertical foundation stiffness and damping to 68 mat foundation nodes using springs and dashpots, considering wall and base contributions and tributary areas.
Example Application (ETABS Demonstration)42:32

Requirements

Basic knowledge of earthquake engineering and familiarity with ETABS software

Description

Soil–Structure Interaction (SSI) is one of the most important yet often overlooked aspects of earthquake engineering. Many structural analyses assume buildings rest on a rigid, fixed base—but in reality, soil flexibility significantly alters structural response during earthquakes.

This course introduces the fundamentals of SSI in a clear, step-by-step manner, based primarily on two authoritative references:

FEMA P-2091: A Practical Guide to Soil–Structure Interaction (2020)
NIST GCR 12-917-21: Soil–Structure Interaction for Building Structures

The course begins with the basics of soil and structural dynamics, develops the principles of SSI, and then demonstrates how to incorporate these effects in practical building analysis using ETABS. By the end, you will be able to confidently model and interpret SSI effects for buildings with raft foundations under earthquake loading.

After completing the course, students will:

Have a strong conceptual foundation in soil–structure interaction.
Be able to apply FEMA and NIST simplified methods to real buildings.
Confidently build SSI-influenced models in ETABS for multi-story buildings with raft foundations.
Interpret SSI results and make informed engineering decisions about their significance.

Course Requirements

Basic knowledge of structural engineering and earthquake engineering is essential.
Familiarity with ETABS software at a beginner level is required.
No prior experience with soil–structure interaction is required.

Who this course is for:

Civil and structural engineering students, especially those specializing in earthquake engineering

Soil–Structure Interaction (SSI) for Building Structures

What you'll learn

Explore related topics

Course content

Introduction to Soil Structure Interaction (SSI)2 lectures • 47min

Fundamentals of Soil Behaviour2 lectures • 49min

Soil-Structure Interaction Effects9 lectures • 4hr 39min

Example Application of Soil Structure Interaction7 lectures • 2hr 27min

Requirements

Description

Who this course is for: