Introduction

A Combined footing is a long footing supporting two or more columns in one row.  Combined footing is commonly used as an alternative [1] when columns are spaced too closely that if isolated footing is provided the soil beneath may have a part of the common influence zone and [2] bearing capacity of soil is such that isolated footing design will require extension of the column foundation to go beyond the property line.

Figure 1. Combined Footing Interface

 

SkyCiv Foundation Design Module (Combined Footing)

SkyCiv Foundation Design Module for combined footings includes the following features:

• Finite Element Analysis (FEA)
• Powerful soil pressure analysis based on FEA results
• Wood-Armer analysis for detailed flexural checks
• Shear and moment diagrams generated from FEA results using the strip average method
• Summary table of design check values and utilization ratios
• Detailed, step-by-step calculation reports, downloadable as PDF or HTML
• Intuitive user interface
• Dynamic graphical representation of the model and results
• Extensive documentation, solved examples, and blog posts to guide engineers through the software

Supported Design Codes and Capabilities

• Full code compliance with American standard (ACI 318 2018 & 2014), Australian standard (AS 3600 2018 & 2009), European standard (Eurocode EN2, EN7 2004), and Canadian standard (CSA A23.3 2014)
• Column offsets in any direction
• User-defined loads in any direction
• Computation of overturning moment and sliding factor of safety
• Support for multiple load cases, such as Dead, Live, Earthquake, and Wind
• Customizable loads, materials, reinforcement, and design criteria

 

Want to try SkyCiv’s Foundation Design software? Our free tool allows users to perform concrete footing calculations without any download or installation!

Foundation Design Calculator