Foundations - Sam Johnson by Sam Johnson https://padlet.com/293474/33ym1frzmiud en-us 2017-01-23 13:36:12 UTC 2017-01-23 14:32:15 UTC hello@padlet.com A foundation is used to support a building or structure and transmits loads directly to the underlying soil or rock. 293474 https://padlet.com/293474/33ym1frzmiud/wish/148698654 2017-01-23 13:39:07 UTC https://padlet.com/293474/33ym1frzmiud/wish/148698654 Types of Foundation 293474 https://padlet.com/293474/33ym1frzmiud/wish/148699127 Pad foundations - Pad foundations are used to support an individual point load such as that due to a structural column. They may be circular, square or rectangular. 

Strip foundations - Strip foundations are used to support a line of loads, either due to a load-bearing wall, or if a line of columns need supporting where column positions are so close that individual pad foundations would be inappropriate.

Raft foundations - Raft foundations are used to spread the load from a structure over a large area, normally the entire area of the structure. They are used when column loads or other structural loads are close together and individual pad foundations would interact.

Pile foundations - Pile foundations are principally used to transfer the loads from superstructures, through weak, compressible strata or water onto stronger, more compact, less compressible and stiffer soil or rock at depth, increasing the effective size of a foundation and resisting horizontal loads. 
]]> 2017-01-23 13:40:35 UTC https://padlet.com/293474/33ym1frzmiud/wish/148699127 Choosing the founation 293474 https://padlet.com/293474/33ym1frzmiud/wish/148700759 Choosing the type of foundation for a building or structure depends on five things;
- The weight of the proposed structure
-  Purpose of the proposed structure
- The ground conditions
- History of the proposed site
- Cost feasibility ]]> 2017-01-23 13:45:16 UTC https://padlet.com/293474/33ym1frzmiud/wish/148700759 Preparing and Excavating foundations 293474 https://padlet.com/293474/33ym1frzmiud/wish/148701699 Before any excavation work starts, you must plan the work carefully and give due consideration to the safety aspects, particularly any potential hazards such as services and cables beneath the ground.
Excavation Depth
The anticipated depth will be marked on the drawings for the work but site conditions as the work proceeds may require that they are deeper than originally specified. Factors such as the proximity, height, and species of any trees will also be taken into account as well as the volume change potential of the soil when excavating trenches.
Setting out Trenches
The first job is to set out a base line for the work. This might be one of the main walls of the new work. All other setting out will be in relation to this so it is important to get it accurately set out.  Fixed points such as the corner of an existing wall are used to establish this base line. Take measurements to the first point on the base line from two known points on your approved drawing and mark the first end of the base line. Repeat the process for the other end. With the base line in place, begin setting out the rest of the lines denoting each of the walls. Lines at right angles to one another can easily be established by using a builders square like the one shown in the picture. When setting out the lines, always double check your measurements, and check that the diagonals of square and rectangular elements are equal.
Excavating Foundation
Determine a suitable order of working. Much will depend on the method you are using – hand digging or use of a small digger. When using a mini digger, you will want to work backwards away from the building if possible so that the machine is sat on solid ground at all times. The bucket used on a mini digger is 600mm wide - the appropriate width for the foundations to be excavated. As the excavating work gets underway, keep a careful watch for buried services such as drains and cables. If any are spotted, stop work immediately and make the area safe before continuing. Failure to do so can result in damage.]]> 2017-01-23 13:47:54 UTC https://padlet.com/293474/33ym1frzmiud/wish/148701699 Foundation Materials 293474 https://padlet.com/293474/33ym1frzmiud/wish/148703432 Different materials can be included in concrete foundations such as;
- Course aggregate
- Fine aggregate
- Cement
- Water
- Steel reinforcement
- Frost proofing
- Accelerators
- Retardants
]]> 2017-01-23 13:52:46 UTC https://padlet.com/293474/33ym1frzmiud/wish/148703432