Middle-third rule

{{Short description|Civil engineering concept}}{{Other uses|Middle Third (disambiguation){{!}}Middle Third}}

In civil engineering, the middle-third rule states that no tension is developed in a wall or foundation if the resultant force lies within the middle third of the structure.

The rule is covered by various standard texts in the field of civil engineering, for instance Principles of Foundation Engineering by B.M. Das.Das, B.M. Principles of Foundation Engineering 3rd Ed. PWS Publishing (1995) p.153 The application of this rule is limited to foundations that are square or rectangular in plan. (For circular foundations a different rule, known as the Middle Quarter Rule applies).