I have been doing work for a mining company for about 10 years. The site engineers are steadily doing less and handing more over to us, an engineering consultant. I have been doing some inconsequential rock anchor designs with little loads. The client likes wall plates with 2 or 4 rock anchors and welding beams to the wall plates to provide lateral or vertical support.
What we use primarily are 20mm diameter anchors (rebar). I am not responsible for the grout or how deep they are drilled. However I would like to be comfortable in my designs.
I have been given a 5 metric ton working load capacity per rock anchor. I have been given a 1 page sample calculation for design of the rock anchor based on a working load. Basically, I must determine the maximum load using "square root of the sum of the squares" and compare that to 5 tons. This seem inadequate for design of structures involving life safety.
Also, sometimes I am given a situation to design a concrete structure to be anchored. Concrete is designed based on ultimate loads, but 1.6 times the 5 tons does not equal the capacity of a 20 dia rebar.
I want to design these safely. Is it really this easy? Is there more to it than what I've been given? If so, please provide for me a reference or something to point to so that I can tell the client that I need more information to design a complicated thing. Or tell me that I am over-thinking this.
Any help is appreciated.
What we use primarily are 20mm diameter anchors (rebar). I am not responsible for the grout or how deep they are drilled. However I would like to be comfortable in my designs.
I have been given a 5 metric ton working load capacity per rock anchor. I have been given a 1 page sample calculation for design of the rock anchor based on a working load. Basically, I must determine the maximum load using "square root of the sum of the squares" and compare that to 5 tons. This seem inadequate for design of structures involving life safety.
Also, sometimes I am given a situation to design a concrete structure to be anchored. Concrete is designed based on ultimate loads, but 1.6 times the 5 tons does not equal the capacity of a 20 dia rebar.
I want to design these safely. Is it really this easy? Is there more to it than what I've been given? If so, please provide for me a reference or something to point to so that I can tell the client that I need more information to design a complicated thing. Or tell me that I am over-thinking this.
Any help is appreciated.