Pullout Capacity Analysis
Due to the DPA design, the vertical pullout capacity may be determined in the same manner as for tension loaded piles. Short-term vertical capacity can be estimated using API Recommended Practice for cohessive soild, i.e. total stress analysis, while long-term drained loading is described by Janbu’s (1973) effective stress approach. The analysis also utilizes a Finite Element code developed by the geotechnical groups at NTNU and SINTEF, i.e. GEOnac PSI, to analyse the horizontal capacity of the DPA.
The following are examples of the result from DPA capacity analysis, taken from Gjøa case:
DPA Pullout Capacity in FLAC3D
A finite difference analysis of the integrated soil and anchor structure when subjected to loading from anchor chain is also performed using the FDM program, i.e. Fast Lagrangian Analysis of Continua in 3 Dimension (FLAC3D)
The analysis considers an embedded DPA in soft to stiff clay sediments loaded at various loading directions and the results are compared to the predicted holding capacity according to API Recommended Practice for pile design