Crap. One of the things I hate is when the insights come after the exam is over. I just finished my third final of this week, geotech. I can already think of two mistakes that I've made.

In one of the problems, we are given the following. There is a site, 12 ft of clay over some gravel and sand, and the water table is at the ground surface. Ten feet of fill with a specific weight of 125 pcf is to be placed over the site, and the water is drawn down 20 ft. Some specs from a consolidation tests are given: 55% water content, 2.7 specific gravity, fully saturated. Additionally, from the test, the compression index was determined to be 0.22, the reloading index, 0.1, and the preconsolidation stress, 800 psf. The two parts that I messed up on....

1)Calculate the amount of settlement expected to occur as a result of the water table draw down and the load from the fill. When I calculated the initial effective vertical stress, I subtracted pore pressure, which I shouldn't have done because there is no pore pressure after the draw down.

2)Determine the additional settlement under the center of a structure that is to be built over the fill, immediately after the placement of the fill, given that it's load is 1500 psf. I didn't calculate the additional settlement but rather, the total settlement including the fill. But all I had to do though was subtract the settlement from just the fill from that total. I could have simplified things a lot, though, by realizing that it's all going to be virgin compression. So I could have just calculated it from the compression index and preconsolidation stress.

Dang it. If only I hadn't been rushed. Took too long on the other problems.

The important part is knowing your mistakes and knowing how to correct them. But it's school and most of us have been socialized to believe that the grade is what matters. I try, but it's hard not to hold a grudge against myself when I know the capability was definitely there to get a great score, but I didn't maximize on it.

Anyway, that's that and that is done.