Session: 10-04-01 Bucket, Gravity Foundations and Caissons

Paper Number: 80775

80775 - The Bearing Capacity of Monopile Foundations Under Combined Loading in Spatially Variable Soil and Local Scour Conditions 

Local scour significantly reduces the bearing capacity of the foundation by removing soil around the foundation and has become one of the key factors causing structural failure in offshore engineering. Monopiles, which have been used most extensively in the offshore wind industries, are usually subject to threat from local scour. The effects of local scour on the bearing capacity of monopile foundations have been studied based on deterministic soil properties and local scour dimensions. However, both the properties of the seabed soil and the dimensions of the local scour have variability. The effects of local scour and the spatial variability of the seabed soil on the bearing capacity of monopile foundations under combined loadings (VHM) are investigated using random finite element method (RFEM) in the present study. Local scour depth was treated as uniform random variable and the undrained shear strength of the seabed soil was simulated with a log-normally distributed non-stationary random field. Additionally, the correlation of local scour depth and soil’s undrained shear strength was taken into account and the effects of the correlation coefficient on the uniaxial bearing capacity and VHM failure envelope for monopile foundations were discussed. Results from the present study can provide guidance to the assessment and design of monopile foundations in spatially varied soil and local scour conditions.

Presenting Author: Jun Liu Dalian University of Technology

Authors:

Jun Liu Dalian University of Technology
Xinshuai Guo Dalian University of Technology
Ping Yi Dalian University of Technology