Building a form for a large concrete pouring job, so this is probably an apprentice concrete finisher or casual laborer. That is about a 12 inch (30cm), or longer, rusty threaded bolt that he is attempting tighten a nut on. Rather than a ViseGrips pliers, some WD40 spray and a closed-end wrench (spanner) would probably be a better choice; but maybe not readily available on a concrete job. (Or, he didn't feel like climbing out of this hole to go look for one.) Also, it looks like he has given up on the task, now spinning the ViseGrips tool counter-clockwise after only gaining an inch (a couple of centimeters) of threading.