Yeah mike it is the same job. The cuts aren't really deep, however they aren't allowing them to blast a lot of the rock, so they are making the rock swiss cheese to help the hydro-hammering. Swiss cheesing the rock can can double or triple the productivity of the hammering, esp when time is of the essence!

Matt,did they know that they were not going to be able to blast alot of the rock,hope so.If not it is going to kill him in cost.What the reason for not being able to blast.When you say swiss cheese the rock do you mean just breaking it up into smaller size.

Mike,
Yes they had anticapated not being able to blast. The costs to shutdown such a major roadway are astronomical. Swiss cheeses means drilling holes on a one by one pattern, a hole every foot thru the natural overburden to keep the productions of the drills high. When you open cut, you cut your drills production by half dealing with the limestone pinaancles. They then come and dig out the dirt to solid rock and follow with a hydro hammer, putting the tip of the hammer in the drill holes to hammer. Once a free face is established, the machines hammers and another removes the rock.

We did a job several years ago where blasting was not allowed and they were hammering with a cat 365. 20 feet of solid rock for a trench. Took them 3 weeks to go 100 feet. The last 200 feet we lined drilled and swiss cheesed and they had it out in a 1.5 weeks!

No matter what you do, when blasting is not an option, rock is very expensive.

You can also line drill, when we did at U of Penn in Philly, which is when you drill holes, 8 inches on center, at the premeter of the building excavation. When complete, it looks like presplit, a very clean rockface still having is structrual qualties.

I'll tell you, from my experceince, they are a first class organization!

Matt,you are right they are a first class company.It just seems to be a mess up job, this would because of the owner.They were moving a pile of topsoil they had already moved once.When they striped it it was very wet and the secord time they moved it, the art. truck couldn't even back up on the pile to dump the load.The dozer had to push it the last 200-300 feet.This had to been done on TM.This is what we were finding on alot of the work we were bidding,the owners wanted everything done yesterday but didn't want to pay for it.