Turns out the problems inside Boston’s Big Dig are more extensive than engineers thought. Bad enough that the boondoggle cost $14.6 billion, but the bolts used to hold up the 3-ton concrete slabs are failing at much lower pressures than they were supposed to handle.
Great. Documents indicate that those concrete slabs were a point of contention during the tunnel’s design phase. Heads are going to roll for this.
Personal connection: Seven years ago, I sold the steel pipe used by a contractor to prop up the tunnels while another contractor went in and started putting in steel and concrete. I’m no engineer, but even then dropping an interstate highway below ground seemed like a really bad idea.