Forms of Substructure
FORMS OF SUBSTRUCTURE
Tutor: David Brooke
Submission Date: 14 December 2012
FORMS OF SUBSTRUCTURE * Table of Contents
Site 1 1
Site 2 2
Site 3 3
Precautionary actions and temporary works 4 1 Bibliography 5
*
Site 1
Dry compact gravel, or gravel and sand subsoil’s are usually suitable for strip foundations. Mostly 700mm to 1000mm deep foundations are acceptable as long ground has suitable bearing capacity.
If the water level is high than the bearing capacity will reduce, so in this case foundations should keep higher than normal. In this condition a shallow and wide strip foundation can be used, and reinforced foundations can also be useful.
As the safe bearing capacity of compact gravel sub soil = 100kN/m² (Chudley & Greeno, 2010)
This safe bearing capacity is for 1 m², for .5 m² it will be 50kN.
W = LoadBearing Capacity
W = 68kN/m ÷100kN/m²1000mm
Required Width = 680mm
It can also be chose from table provided, according to which because loading size is nearly 70kN/m for which 650mm wide foundation is required.
As per table accurate measure can be: 650mm70kN/m×68kNm=631 mm
So foundation width can be 635 mm wide or for safety it can be increase up to 650mm.
As the plot is adjacent to coast it is difficult to pump the water outside. Piled foundations can be another option which can be use to do the construction in coastal environment.
* Site 2
As the subsoil is Clay, Short Bored Piles foundation can be used it will be suitable for two story domestic building. As the plot was used as an orchard before so the moisture which was stopped due to trees will come again and cause soil swelling. So heave will occur on this type of plot. Due to heave deeper foundations need to build, by this cracks will not occur in foundations. Again pile foundations can be use on this type of land. Water can be pump out from the site. (Chudley & Greeno, 2010)
Heave is upward movement of soil. It is the process when moisture added
Tutor: David Brooke
Submission Date: 14 December 2012
FORMS OF SUBSTRUCTURE * Table of Contents
Site 1 1
Site 2 2
Site 3 3
Precautionary actions and temporary works 4 1 Bibliography 5
*
Site 1
Dry compact gravel, or gravel and sand subsoil’s are usually suitable for strip foundations. Mostly 700mm to 1000mm deep foundations are acceptable as long ground has suitable bearing capacity.
If the water level is high than the bearing capacity will reduce, so in this case foundations should keep higher than normal. In this condition a shallow and wide strip foundation can be used, and reinforced foundations can also be useful.
As the safe bearing capacity of compact gravel sub soil = 100kN/m² (Chudley & Greeno, 2010)
This safe bearing capacity is for 1 m², for .5 m² it will be 50kN.
W = LoadBearing Capacity
W = 68kN/m ÷100kN/m²1000mm
Required Width = 680mm
It can also be chose from table provided, according to which because loading size is nearly 70kN/m for which 650mm wide foundation is required.
As per table accurate measure can be: 650mm70kN/m×68kNm=631 mm
So foundation width can be 635 mm wide or for safety it can be increase up to 650mm.
As the plot is adjacent to coast it is difficult to pump the water outside. Piled foundations can be another option which can be use to do the construction in coastal environment.
* Site 2
As the subsoil is Clay, Short Bored Piles foundation can be used it will be suitable for two story domestic building. As the plot was used as an orchard before so the moisture which was stopped due to trees will come again and cause soil swelling. So heave will occur on this type of plot. Due to heave deeper foundations need to build, by this cracks will not occur in foundations. Again pile foundations can be use on this type of land. Water can be pump out from the site. (Chudley & Greeno, 2010)
Heave is upward movement of soil. It is the process when moisture added
Bibliography: Chudley, R., & Greeno, R. (2010). BUILDING CONSTRUCTION. Oxford: Elsevier Ltd.