How do you measure ground bearing capacity?
Researchers can calculate the bearing capacity of soil by determining the limit of contact pressure between the soil and the material placed on it. These calculations and measurements are performed on projects involving bridge foundations, retaining walls, dams and pipelines that run underground.
How do you calculate ground bearing pressure for a mobile crane?
Simply divide the maximum outrigger load by the allowable ground bearing pressure to determine the pad area you need. Example: Maximum outrigger load = 100,000 lbs. Allowable ground bearing pressure = 3,500 psf. (100,000 lbs / 3,500 psf = 29 ft2 of area).
How is mobile crane capacity calculated?
(r)(hC)/100 is the standard formula for calculating maximum crane power.
How do you calculate bearing capacity?
It is widely accepted that the bearing capacity factors Nc and Nq are correlated with each other through the following formula:
- Nc = (Nq – 1)cotϕ
- qu + ccotϕ = (q + ccotϕ)Nq + ½γBNγ
- pu = λNq + ½Nγ
- Nγ = 2pu – 2λNq
- N q = e π tan ϕ tan 2 π 4 + ϕ 2.
What is ground bearing capacity?
In a nutshell, bearing capacity is the capacity of soil to support the loads that are applied to the ground above. It depends primarily on the type of soil, its shear strength and its density. It also depends on the depth of embedment of the load – the deeper it is founded, the greater the bearing capacity.
What is soil bearing capacity?
How do you calculate ground pressure?
Average ground pressure can be calculated using the standard formula for average pressure: P = F/A. In an idealized case, i.e. a static, uniform net force normal to level ground, this is simply the object’s weight divided by contact area.
How is crane SWL calculated?
To calculate the SWL of lifting chain in kilograms, multiply the diameter (D) in millimetres (mm) squared, by the grade (G), by either 0.3 or 0.4. For Grade 80 chain, use 0.4, and for Grade 30 or 40 chain, use 0.3. For example: Chain diameter, 10 mm.
How do you calculate load capacity?
Calculating Load
- Add together the wattage capacity of all general lighting branch circuits.
- Add in the wattage rating of all plug-in outlet circuits.
- Add in the wattage rating of all permanent appliances (ranges, dryers, water heaters, etc.)
- Subtract 10,000.
- Multiply this number by .
- Add 10,000.
What is the normal soil bearing capacity?
1; CABO One- and Two- Family Dwelling Code; 1995….Soil Bearing Capacities Chart.
| Class of Materials | Load-Bearing Pressure (pounds per square foot) |
|---|---|
| Sedimentary rock | 6,000 |
| Sandy gravel or gravel | 5,000 |
| Sand, silty sand, clayey sand, silty gravel, and clayey gravel | 3,000 |
| Clay, sandy clay, silty clay, and clayey silt | 2,000 |
What is a good soil bearing capacity?
Typical values of soil bearing capacity
| Soil type | Bearing value (kPa) | Remarks |
|---|---|---|
| Medium dense sand | 100 – 300 | – |
| Very stiff boulder clays and hard clays | 300 – 600 | Susceptible to long term consolidation settelement |
| Stiff clays | 150 – 300 | – |
| Firm clays | 75 -150 | – |
What are the allowable bearing values for a crane cap?
Allowable Bearing values (presumptive) in psi Hard Rock 100 1390 Soft Rock 12 167 Very compact sandy gravel 10 139 Loose fine sand or firm inorganic silt 1,5 21 18 Ground Condition and Preparation for Mobile Cranes Background load distribution Crane Cap.
Do mobile cranes have load charts for outriggers?
Some mobile cranes have load charts for mid-extended outrigger beams. For such cranes, the outriggers should still be extended to the proper point and all of the tires must be clear of the ground.
What are the conditions required for a crane to operate?
The ground condition must have enough stability and bearing capacity to support all loads placed on it by the crane. Extreme caution should be used when performing lift operations beside buildings, especially if newly constructed with uncompacted backfill, along trenches, or in areas where water mains, sewer pipes or steam lines are buried.
What is the sail area of load on a mobile crane?
Example Only Mobile cranes are designed with a standard drag factor of 1.2 and a wind area/weight of 1.2 m²/tonne. This means that certain types of loads will produce higher side loads on the crane than it is designed to take Sail Area of Load 2.5 X 8 = 20m² (Sail Area)