GGU-RETAIN: Excavations and waterfront structures using the p-y method

Generally, retaining walls and waterfront structures are calculated according to Blum's method.

The calculation of dolphins presents a comparable problem. Blum's method can also be used here. For dolphins, the so-called p-y method is preferred, especially on an international level.

This paper examines whether the use of the p-y method is possible and reasonable for excavations and waterfront structures.

The p-y method is a non-linear modulus of subgrade reaction method and can be used for pile diameters < 2.5 m. In the literature, p-y curves can be found for non-cohesive soils (without cohesion) and for cohesive soils (without friction angle). The figure below shows a p-y curve for sand.

The curve describes the magnitude of the earth resistance (p) in front of the pile as a function of the pile displacement (y).

Sample calculations show good agreement between Blum and p-y method.

Advantage of the p-y method:

• Realistic deformations with comparable state variables.

Disadvantages p-y method:

• No curves for soils with friction angle and cohesion.

• No curves for inclined ground.