Calculator For Engineers

I was searching for a website which can do small quick calculations for example calculate moment of inertia, section modulus, plastic section modulus etc. and found following website. Hope this will be very helpful.

Screenshot 2014-08-26 17.04.58


Zero Compression Element

When we want to model tension cable rods or any member with zero compression  and want to use finite element model for this purpose then follow the procedure below. This procedure is written considering CSI products (SAP or ETABS) but the concept should be similar for most of the softwares.


  1. Select the frame elements which should not take any compression.


  1. Click Assign > Frame/Line > Tension/Compression Limits.


  1. Check the box for Compression and define a limit of zero in the text box (default=0)



In order to run the analysis for tension-only members, we have to run Non-Liner Static analysis which is very simple.

  1. Go to Define > Load Cases and select the case you want to change to non-linear static (usually lateral load cases).
  2. Select Non-Linear Static from the pull down menu.


  1. Input other load cases in the box with appropriate load factors.
  2. Run the analysis and check the members with no compression and confirm that members are only taking tension.
  3. Perform the design.


Alternate option for defining non-linear load cases:

  1. Click Define > Load Combination
  2. Select Load combinations needs to convert to Non Linear combos



  1. Click button ” Convert Combos to Nonlinear Cases
  2. Run Analysis and check the forces in the members.
  3. Perform the design.


Biggest Bridge Slide Ever!!!

Watch the video and admire the engineering:

Here is the brief description of project:

On April 10, 2014, the slide of the Milton-Madison Bridge was completed. At nearly a half-mile long, this is the longest bridge slide of its type in North America, perhaps the world. The slide occurred over a two day period with the actual slide time being approximately 12 1/2 hours. The total slide distance was 55 feet, going from temporary piers to refurbished, permanent piers.

The old bridge was where the new bridge is today – after the slide. The new bridge was built on temporary supports NEXT TO the old bridge. The old bridge still carried traffic. After the new bridge was built, traffic was switched to the NEW Bridge on the temporary alignment. The old bridge was demolished. The existing piers were rehabilitated. After that work was complete, the new bridge slides back over where the old bridge used to be. By reusing the foundations and piers the owner saved many tens of millions of dollars.