Shoring is a big question to me, as most of our site boss's can not give strait answers to setup limitations to a 30-100ft vertical walled dig site. Question, should I be aproching the engineer on distances and give pad weights.

These are shored shotcreted verticals (anchored)

What an excellent question!

I could show you photos of a 52meter whos operator thought that it was automaticly OK to set up on the site you described. They ended up loading his boom onto a truck in 10 foot chunks. It was not pretty.

I saw a picture on either Brundage & Bone's or one of the manufactures web sites that shows the correct way to do it. They had a sheet of 1" steel under the outriggers to spread the load to an acceptable loading factor. THAT is the way to do it. Crane pads are another way to minimize the loading on the ground close to an excavation. Crane pads would be my first choice.

Considering the very small area that you have on your machine for extra dunnage I think that some preplanning with the responsible contractor would be in order.

I sure am glad you asked this question, this was to be one of my 'Safety Messages' in the future. By your bringing it up now perhaps you have saved some unlucky operator the surprize of his life.

Thanks ;~)

Bob Sanderson

www.ConcretePumpingSafety.com

Well thanks Bob I am responsible now to prepare these sites for our machines, and this question has been crawing at me. I use to shore prior to pumping, and trust anchors, maybe more than most, I have set 50s over the anchored earth, there are many signs of a kipped anchor. But the knowing question is how stable is that anchor. What forces from above can they take. 30,000 lbs per square inch on the top anchors, atleast around here. And anchor failure is definatly a possability. I will be talking to an engineer soon on a pour site, it is only two stories deep, and the rule there is 8ft back from the edge with a 43m. He must either know outrigger forces or is covering the heaviest case machine. I will try to drill for info.

This is an interesting topic. Could someone post some pics of sights like this. I would like to see your pics also Bob. Once again Great Topic!

I need time and will post some shots maybe midweek. I have been preaching this subject alot over the years to deaf ears, but now in the position to stress it, I will find some answers. This is about large commercial sites that pull their access ramps and pump from the streets, generaly 5+ stories deep. Shoring is in place but by no means does this allow the 1 for 1 rule. 100ft deep 10ft from it.

The one to one rule is not a factor in a re-shore excivation situation. What is very important is the information from the engineer on what the load imposed on the ground at street level can be. At that point it is imperative that the pump company remain BELOW that load rating.

If it [for example] 35psi then the pump had better not exceed that load. We pumpers need to be smart enough to know what questions to ask, and then armed with the CORRECT information, make the right moves to insure that we are well with in that boundry of safety.

FOREWARNED IS FOREARMED.

;~)

I need to find that formula, like rigger weight full extention of boom, to kipped anchor then still go over it with engineer.Example: one site has trolly wires so to use a 43m it will sit direct under the trolly wire. They have to be protected and flaged then the machine has no choice but to prime in the hole and blow out in the hole. a 36m lighter machine could get closer and avoid being under the trolly wires, thus prime in itself then move to hole and blow back into truck.Hard job to figure, maybe take more room and night pour but residential downtown. Plus busy traffic and bus route hehe, I dont get paid enough.

The only thing he needs is the downforce imposed. It is on each outrigger. If not there call the manufacture.

Thanks bob.