Laboratory Testing and Detailed Geotechnical Design of the Mad Dog Anchors

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe Mad Dog Spar is moored by suction anchors arranged in three Clusters. Two anchor Clusters lie on top of the Sigsbee Escarpment while one anchor Cluster lies in a slump unit below the Escarpment. The soil conditions at the 4 pile locations in the slump deposit vary significantly and are very different from the soil conditions on top of the Escarpment. This dictated the need to make five different designs. This paper describes how the undrained shear strength selected for design was determined by combining the various soil conditions detected by CPT with the results from advanced and index laboratory testing. The design procedures used to design the anchors are explained in this paper. Also presented in the paper are the governing load cases together with results from holding capacity calculations using an efficient 3 D FE program.

Centrifuge Testing on Suction Anchors: Double-Wall, Over-Consolidated Clay, and Layered Soil Profile

“…This paper presents partial results from two separate series of centrifuge tests to investigate the holding capacity of suction anchors in soil profile representative of the Mad Dog Cluster 2 conditions (see Schroeder et al, 2006) and to separate the components of total vertical capacity: outside friction, inside friction, and end bearing.…”

“…The first series addressed the specific conditions of the Mad Dog Cluster 2 anchors on the Sigsbee Escarpment , and Schroeder et al 2006. Tests were performed for soil conditions, anchor geometry, attachment points, and loading angles closely matching the Mad Dog design parameters.…”

“…

TX 75083-3836, U.S.A., fax 01-972-952-9435.

AbstractThis paper presents partial results of two series of centrifuge tests that were performed on suction anchors.The first series addressed the specific conditions of the Mad Dog Cluster 2 anchors on the Sigsbee Escarpment , and Schroeder et al 2006. Tests were performed for soil conditions, anchor geometry, attachment points, and loading angles closely matching the Mad Dog design parameters.

…”

Setup Characteristics of Suction Anchors for Soft Gulf of Mexico Clays:Experience From Field Installation and Retrieval

“…Details of the Mad Dog site geotechnical conditions can be found in Schroeder et al (2006). Tests were run on samples in Cluster 1, 2, and 3.…”

“…In order to calculate the ratio α , preferably determined as suggest by Andersen and Jostad (2002) and detailed by Schroeder et al (2006). Unfortunately such data was not available for the clays in the database.…”