CHAPTER ONE
1.1. INTRODUCTION
Foundation is that part of the structure which transmits the load from the superstructure to the soil without any kind of distress in the superstructure as well as the soil. The foundation also known as substructure can be broadly classified into two types; (i) Foundation structure and (ii) Retaining structure. The foundation structure is mainly subjected to vertical loads, transmitted from the super structure while the retaining structure is mainly subjected to the horizontal loads, the earth pressures. As both the structures are concerned with the contact with the soil, so it has been classified under the Foundation Systems as the broader field.
The figure below shows the flowchart of the foundation system showing the foundation structure and retaining structure outlay
Structures
Fig. 1.1 Flowchart of Foundation system
Estimation of bearing capacity of foundation is an important parameter in the design of any substructures. In geotechnical engineering, bearing capacity is the capacity of soil to support the loads applied to the ground. The bearing capacity of soil is the maximum average contact pressure between the foundation and the soil which should not produce shear failure in the soil. Ultimate bearing capacity is the theoretical maximum pressure which can be supported without failure; allowable bearing capacity is the ultimate bearing capacity divided by a factor of safety. Sometimes, on soft soil sites, large settlements may occur under loaded foundations without actual shear failure occurring; in such cases, the allowable bearing capacity is based on the maximum allowable settlement.