Reference no: EM132852501
CEE 4074 Construction Means & Methods - Virginia Polytechnic Institute and State University
Exercise - Crane Load Transfer to Ground
Instruction
- Discuss the earthwork problem among your in-class breakout group to begin formulating a solution to answer the questions.
- Individually upload your worked solution into Canvas, in PDF format, by Friday (4/9) at 11:59 PM. Excel may be used as a tool, but an Excel file will not be received for grade.
- Use the CEE 4074 computation worksheet (Canvas/Files/Spring 2021 Content/Resources), or scanned engineering paper, to show your derived solution. Show all work in a neat and organized format, and highlight your answers.
Problem
You are responsible for planning and executing a lift using a mobile 80-ton hydraulic crane. The crane weighs 79,908 lbs, including the hook block and operator, but no counterweight. You have determined that a 5-ton counterweight will be required for the lift.
Based on evaluation of the pick and placement locations, and load's weight, a boom length of 100 ft will be required and will result in a rated (maximum safe lift) load of 25,250 lbs (i.e. load plus rigging weight).
The crane's outrigger pads ("floats") are circular in shape, and 36 inches in diameter.
Assume that the crane's operating weight will be equally distributed among the four outriggers, and during the lift movement the most severe loading will be the full rated load carried by a single outrigger.
Determine:
1. The expected maximum contact stress beneath the most severally loaded outrigger (nearest 1 psf); and
2. The side dimension of a square, wood cribbing mat (nearest 1 ft) for the maximum outrigger loading (Item 1) to not exceed the ground's allowable bearing capacity of 3,000 psf.
Attachment:- Crane Load Transfer to Ground.rar