Pile Foundation A shallow foundation is usually provided when the soil at a shallow depth has adequate capacity to support the load of the superstructure. However, in situations where the soil at shallow depths is poor, in order to transmit the load safely, the depth of foundation has to increased till a suitable soil stratum is met. In view of increased depth, such foundations are called deep foundations. Piles, Piers and Wells are example of deep foundation. What is Pile foundation? A pile is a relatively small diameter shaft, which is driven or installed into the ground by suitable means. The piles are usually driver in groups to provide foundations for structures. The pile groups may be subjected to vertical loads, horizontal loads or a combination of vertical and horizontal loads. This piles are usually made of concrete and steel which are used to support the structure and transfer the load at desire depth either by end bearing or skin friction. Where pile foundation are ...
Stress and Strain Curve for Mild Steel Pic-1 shows a typical tensile test specimen of a mild steel on a universal testing machine. Its ends are gripped into universal testing machine. The length between two gripped portion is L 1 The load is applied gradually and at regular interval of loads extension is measured. After a certain Load, extension increases at faster rate. the extension is measured from scale on the universal testing machine. load is increased gradually till the specimen breaks. Pic 3 shows stress vs strain diagram for the typical mild steel specimen. The following salient points are observed on stress strain curve. 1. Limit of Proportionality (A) : it is the limiting value of the stress up to which stress is proportional to strain. 2. Elastic Limit: This is the limiting value of stress up to which if the material is stressed and then released(unloaded) strain disappears completely and the original length is regained. This point is sligh...