Built Up Timber Column

[Hromis1]

Ladies and gents, I working problem 80 from the 6 minute structural 1 book. Something strikes me as odd in the problem statement versus the picture and the figure 15B in the NDS book.

The problem states that the built-up column is nailed per section 15.3.3. However, 15.3.3.1 (a) states "adjacent nails are driven from opposite sides of the column". NDS figure 15B appears to show the nails all from the same side of the column. The picture from problem 80, clearly shows all nails from the same side.

What is our opinion. Is this a goof in the problem and also a goof in the NDS book? or am I mis-interpreting this.

 

[Phalanx]

Hromis1,

The nailing pattern should have nails on both sides of the built-up column. NDS Figure 15B is only a general representation - i.e. the fasteners could be bolts or nails. Check out NDS Figure 15C. That figure shows a few examples of built-up columns using nails. I don't have the 6 minute book, but if it shows nails on one side only, it is incorrect.

 

[MOOK]

Hromis 1

There are many many mistakes in 6min book either in the problems or in solutions.

 

[Hromis1]

Mook,

You are correct. I had an old version of this book and it as full of errors that I used years ago. I purchased a new edition thinking that they had corrected many of these. I'm still finding "issues".

IE the solution for #92 has a big problem in the solution and problem statement. It is a sliding check on a retaining wall. The problem statement calls the soil under the footing and back fill "Sandy without Silt" with no mention of gravel. Per IBC table 1804.2 the coef of friction should be 0.25 for "sand". However, the solution uses 0.35 as it were a sandy gravel.

The teaching approach in the book is good. But I'm disapointed in these errors.

Hromis1