Coastal regions are often associated with high seismic risk, due to fault lines between oceanic and continental plates, such as at the Pacific Rim. Plate boundaries also affect other coastal regions, including the Middle East and the Indian sub-continent.
Designing structures to withstand earthquakes is therefore often a key requirement for maritime developments.
Royal HaskoningDHV is a member of the Society for Earthquake and Civil Engineering Dynamics (SECED) and is active in raising awareness of seismic hazards. Operating at the forefront of current thinking on seismic resistant construction, we undertake seismic analysis of complex maritime construction projects, such as the Iconic Bridge in Dubai, and the Coatzacoalcos immersed tunnel in Mexico as well as a host of port and harbour projects.
Design methods for seismic resistant maritime structures are developing rapidly with displacement based design approaches becoming increasingly common. Royal HaskoningDHV are involved in updating the latest standards such as ASCE 61-14. Our approach is to keep up with the latest advances while also maintaining the use of more traditional methods where these are adequate and have performed well in the past.
Our work includes planning and designing ports, dockyards and navigation canals for construction in areas of seismic activity. As part of this work we prepare seismic resistant designs for a range of structures including:
- Large quays and dock walls (including pile supported deck structures, gravity walls and sheet pile walls)
- Mooring and berthing structures, jetties, wharves and breakwaters
- Dry docks, large dock gates and structures for ship lifts
Seismic design criteria
The approach to seismic resistant design is highly dependent on the type of project, the site specific conditions and the structure type. For instance, facilities handling hazardous materials, such as LNG, need to be designed to resist extreme events and are governed by specific standards. Likewise, poor ground conditions can significantly exacerbate the effects of earthquakes leading to problems such as liquefaction and large ground movements affecting the foundations. It is therefore particularly important for projects in seismic zones to set out the specific design requirements and prevailing conditions at an early stage.
Seismic engineering and design
We specify and interpret surveys and investigations specifically for seismic design. Designs are carried out using the approaches best suited to the particular structure and ground motion intensity. In some cases relatively simple procedures may be adequate while large projects on difficult sites often require complex state-of-the art calculations. Where appropriate, analyses will include liquefaction assessments, soil-structure interaction and post-elastic structural behavior (pushover analysis).
Our work is designed to adhere to the various international seismic engineering codes:
- Eurocode 8 –Design of Structures for Earthquake Resistance
- American Society of Civil Engineers (ASCE 61-14, 7-10, 4-98)
- PIANC WG34 – Seismic Design Guidelines for Port Structures
- NFPA 59A - Standard for the production, storage, and handling of LNG
A large number of national seismic codes including Colombia, Egypt, India, Indonesian, Japan, Jordan, Peru, Russia, Turkey, Vietnam