Shallow foundations

For shallow foundations, especially those of offshore gravity structures, the depth factor has almost negligible effect on the calculated bearing capacity. In this connection, use... 

Meyerhof, G. G. (1965), Shallow foundations. Journal of the Soil Mechanics and Foundation Engineering, ASCE, 91, No. SM-2, pp. 21-31. 

Very suitable These are areas underlain by in situ deposits (clay, sandy to clayey silt and clayey sand) formed from the weathering of igneous intrusive, sedimentary and metamorphic rocks. They have a shallow foundation level or rockline (1 to 10 m) with no danger of subsidence expected and a little or no fill required. 

For shallow foundations such as footings, design curve on allowable bearing capacity from studies carried out with Mackintosh (JKR) probe by Ooi Ting (1975) is available and reproduced in Figure 3.10. 

For application to shallow foundation design, it is commonly considered that the general shear case applies to dense granular soil and to firmer saturated cohesive soils subject to undrained loading. The punching shear case is considered appropriate for compressible soil, such as sands having a low to medium relative density, and for cohesive soils subject to slow loading. 

The ultimate bearing capacity, q it, for the soil zone supporting a shallow foundation, based on theoretical considerations with empirically determined modifications, has been related to the limit pressure as follows ... 

The settlement. A//, of a shallow foundation situated in homogeneous soil can be estimated from ... 

Vesic, A.S. 1975. Bearing capacity of shallow foundations. InH.F. WinterkornandH.Y. Fang, eds., Foundation... 

Almost all structures constructed on earth will transmit their load to the earth through their foundation. In other words, foundation is the lowest part of a structure, which is in contact with the soil and transmits the load of the structure to the ground. Therefore the design of the foundation is very important to ensure the stability of the structure it supports. Foundations are generally divided into two categories - shallow foundation and deep foundation. 

A shallow foundation is foundation built near or at ground (soil) or rock surface. This foundation is placed on firm soil near the ground and beneath the lowest part of the superstructure. Examples of these foundations are pad footing and spread footing. Deep foundation on the other hand is foundation that transmits structural loads to deeper soils or rock layers that are far from the surface. This foundation is constructed on a soil that is not firm, and transmits the load of the structure considerably below the ground of the lowest part of the superstructure. Deep foundations can be divided into two categories, that is pile foundation and drilled pier foundation or caisson. Piles are normally columns made of concrete, wood, plastic or steel that are driven into the ground. Drilled pier or caisson on the other hand is a special pile made of cast in situ concrete inside a bored or drilled hole. 

NUMERICAL EXAMPLE RELIABILITY ANALYSIS OF A SHALLOW FOUNDATION... 

Figure 4. Bearing failure surface of a shallow foundation with pure vertical loading.

Susceptibility of Shallow Foundation to Rocking and Sliding Movements During Seismic Loading... 

This chapter investigated the soil-structure interaction problem of a shallow foundation located on dry sand and subjected to seismic loading. Centrifuge tests and a detailed analysis were performed and allowed the rotation, settlement and sliding behavior of the foundation to be studied and understood. It was found that ... 

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