Lab-3 Question about Piers

Question:

I had a question about Quest 4 & 5. Since we have two piers that make up the one pier which is being impacted by the tanker. Would you have to multiply the height by 2 to account for both piers when calculating for the Moment? I assumed that it would only have be just the height of the first pier since thats the one the tanker is actually making contact with. Does the same apply for the section modulus? would the section modulus need to be multiplied by two to take into amount there are two piers?

Answer – Prof. Dasaro:

No. You don't multiply the height of the piers by 2. They are what they are. What you adjust is the stiffness of the two-pier system by increasing the given k value by a factor of two. This is because two piers share the tanker load and the given k value is the stiffness for only one pier. You do that in Question 2.