HYD verifications using numerical methods

ABSTRACT

HYD, as described in Eurocode 7 (EC7), is related to the upward flow of water through the soil towards a free surface, such as in front of a retaining wall or in the base of an excavation. The HYD verification, using numerical analysis, can be performed with two different approaches. The first approach is the conventional soil block approach where safety may be checked by calculating the equilibrium of a rectangular block of soil. The second approach is the integration point approach where stability can be verified at every integration point in the numerical analysis by checking that the equilibrium is satisfied for a soil column of negligible width above each point. In this paper, the two approaches are described and their advantages and disadvantages are discussed. Comparisons made using benchmark geometries, extensively studied and discussed between the members of the EC7 Evolution Group 9, on Water Pressures, illustrate that the HYD verification using numerical methods seems very promising. Thorough comparisons between the factors from the two approaches allow designers to better understand the benefits of using more advanced and robust approaches for such stability verifications.

KEYWORDS:

• HYD
• hydraulic heave
• Eurocode 7
• water pressures

Acknowledgements

The authors gratefully acknowledge the support of the project partners, EPSRC and Arup. Special thanks are extended to Brian Simpson from Arup Geotechnics and the other members of the EC7 Evolution Group 9 for the useful discussions.

Disclosure statement

No potential conflict of interest was reported by the authors.