Plenary Lecture

Plenary Lecture 2 On Welded and Grouted Connections in Offshore Tubular Steel Structures
Date / Time 09 December 2019, Monday / 10:40 - 12:00 hrs
Venue Lecture Theatre 6
Speaker Inge Lotsberg
DNV GL, Veritasveien, Høvik, Norway


This paper gives an overview of some of the most significant challenges and developments of welded and grouted connections in tubular structures subjected to dynamic loading in the North Sea the last 40 years. This includes design of tubular joints which may be designed with stubs to allow for welding from the inside and tubular joints welded from the outside only. In many structures the transition from one tubular thickness to another may be required. The development of stress concentration factor for these connections is presented. Conical connections are frequently used in framed tubular structures and some design guidance related to these together with relevant references are presented. The latest developments related to grouted connections in traditional jacket design, jackets with preinstalled piles and towers on monopiles are presented. Grouted connections are efficient to make connections of structural elements with large tolerances and for making connections below water.


Inge Lotsberg has a doctoral degree in structural mechanics from the University in Trondheim in 1977. He has worked in DNV and DNV GL since 1979 with design assessment of steel structures, with development of design standards within DNV GL, Norway and ISO related to design of steel structures and grouted connections. He has published more than 130 papers and one book related to fatigue and fracture mechanics, reliability analysis and laboratory testing of steel structures and grouted connections.