Void porosity measurements in coastal structures

Void porosity measurements in coastal structures

Bosma, C.
Verhagen, H.J.
D'Angremond, K.
Sint Nicolaas, W.

Civil Engineering and Geosciences

Hydraulic Engineering

2002-01-01

The paper describes the use of two fundamental design parameters, the void porosity and layer thickness in rock armour constructions. These design parameters are very sensible for factors such as the boundary definition of a rock layer, rock production properties, intrinsic properties and construction properties. Differences in the value of the design parameter cause a considerable (financial) risk. This risk contains two directions, the first is the affection on the hydraulic performance of the structure and the second is its relation with materials procurement. This paper describes and investigates the second risk for the contractor: the large margin in the calculation of the void porosity, which influences the amount of rock (in weight). Often this risk is on account of the contractor, so it is necessary to have better insight in these values in order to reduce the financial risk. Focus is on the variation of the porosity at the bottom, at the top and at the transition between two layers of graded material. This has resulted in correction coefficients for the layer thickness, as well as for the computation of the void porosity as a basis for payment by the client.

filters
porosity
void ratio
bed protection

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American Society of Civil Engineers

Coastal Engineering 2002: Proceedings of the 28th International Conference, 7-12 July 2002, Cardiff, Wales

Institutional Repository

conference paper

© 2002 TU Delft