CH2M Staff Construction Engineer interview questions

I was asked lots of questions regarding problem solving skills under specific situations. For example, what would you do if you have several project schedules which are overlaped?; how would you maintain quality under certain situation? etc. There were also few very odd questions. One question I remember is that why manhole covers are round. Whole phone interview lasted more than an hour. It is adivised to be prepared to answer questions directly related to current projects.