The most recent SCOSS and CROSS newsletter has a headline that is a slap in the face, and almost certainly a deserved one. Report number 858 is “Repeating the same mistakes” and it describes areas where engineers are literally dong that. The whole purpose of forensic investigations, from the engineers’ perspective, is to understand what …

Repetition Read More »

Strain Compatibility Visualized

Some engineering concepts are easy to explain. For example, the idea that stress and strain are related can also be expressed, crudely, as objects squash when you push on them. Everyone understands that on an intuitive level. Other concepts, like strain compatibility, are a little more difficult. The short version of strain compatibility, if I …

Strain Compatibility Visualized Read More »

Changing Standards

That’s the interior of the bulkhead where a stair meets the roof in an old fire-rated building. Too bad the bulkhead’s not rated, as the steel frame (made of angles and channels) that supports the roof and walls is not in any way protected against fire. Here’s an annotated version to make it clearer: The …

Changing Standards Read More »

Why Did They Do That?

A large part of field investigation is trying to get inside the head of whoever designed and built the structure you are looking at.* The idea is that people do things for rational** reasons so if we can figure out those reasons we have a head-start on understanding the built result. The more you understand …

Why Did They Do That? Read More »

Scroll to Top