Alan G. Young

Bio: Alan G. Young is an academic researcher. The author has contributed to research in topics: Bearing capacity & Foundation (engineering). The author has an hindex of 3, co-authored 4 publications receiving 63 citations.

Foundation Performance of Mat-Supported Jackup Rigs in Soft Clays

Abstract: Mat-supported jackup rigs often experience mat penetrations approaching the thickness of the mat in soft soil areas. Data obtained with an electronic bottom sensor show that actual mat penetrations differ from divers' observations because of a soil mound that forms near the mat's edge. This paper compares the mat penetration data with various bearing capacity procedures and strength data to help assess which procedure gives the most accurate prediction. It describes geologic features and soil properties that may influence the foundation performance of these rigs. The paper concludes by recommending types of geophysical and geotechnical studies to be performed to evaluate the expected foundation performance of mat-supported rigs more thoroughly.

Ship-Shaped Offshore Installations : Design, Building, and Operation

Abstract: Ship-shaped offshore units are some of the more economical systems for the development of offshore oil and gas, and are often preferred in marginal fields These systems are especially attractive to develop oil and gas fields in deep and ultra-deep water areas and remote locations away from existing pipeline infrastructures Recently, the ship-shaped offshore units have been applied to near shore oil and gas terminals This 2007 text is an ideal reference on the technologies for design, building and operation of ship-shaped offshore units, within inevitable space requirements The book includes a range of topics, from the initial contracting strategy to decommissioning and the removal of the units concerned Coverage includes both fundamental theory and principles of the individual technologies This book will be useful to students who will be approaching the subject for the first time as well as designers working on the engineering for ship-shaped offshore installations

Numerical Simulation of Vertical Pullout of Plate Anchors in Clay

Abstract: The behavior of strip and circular plate anchors during vertical pullout in uniform and normally consolidated clays was studied in this paper by means of small strain and large deformation finite-element analyses. Both fully bonded (attached), and “vented” (no suction on rear face), anchors were considered. The current numerical results were compared with existing laboratory test data, finite-element results, and analytical solutions. This study showed that, in small strain analysis, the scatter of existing data was mainly due to the effect of soil stiffness. In large deformation analysis, when soil and anchor base were attached with suction, the pullout capacity factor formed a unique curve independent of the soil strength ( su ) , soil effective unit weight ( γ′ ) and anchor size ( B =width of strip anchor and D =diameter of circular anchor). The transitional embedment depth ratio, HSD ∕B or HSD ∕D , (where HSD =transition depth between shallow and deep embedment) was 1.4 for a strip anchor and 0.75 for...

Setup Following Installation of Dynamic Anchors in Normally Consolidated Clay

Abstract: This paper describes a series of centrifuge model tests designed to assess the increase in capacity of dynamic anchors due to setup in normally consolidated clay. The tests involved measurement of the vertical capacity of 1:200 reduced scale model anchors following various periods of postinstallation consolidation. The short-term capacity was shown to be dependent on the anchor impact velocity. Cavity expansion solutions for consolidation around a solid driven pile were found to provide agreement with the experimental results. A simplified capacity calculation technique predicted higher friction ratio values than is typically observed for driven piles; however, these calculations were complicated by the unusual dynamic anchor load — displacement response and uncertainty regarding the true sample shear strength. Dynamic anchor consolidation proceeds at a slower rate than for suction caissons and open-ended piles of similar equivalent diameter. However, the results indicate that depending on the site conditions, dynamically installed anchors remain a viable alternative to conventional deep-water mooring techniques.

Loss in Anchor Embedment during Plate Anchor Keying in Clay

Abstract: Vertically installed plate anchors have been investigated in this paper by numerical analysis and centrifuge modeling. In the numerical analysis, the large deformation finite-element method (remesh...

Influence of the installation process on the performance of suction embedded plate anchors

Abstract: This paper describes a series of centrifuge tests performed in order to investigate the influence of the installation process on the capacity of a suction embedded plate anchor. A 1/145th reduced scale model suction caisson and plate anchor were used for this purpose, embedded in a normally consolidated clay sample. The full installation and retrieval process was simulated as well as loading of the anchor to failure. Results are compared with similar pullout tests where the anchor was pre-embedded manually in the sample. The keying process and the anchor capacity were also investigated. Results show a loss of performance of the suction embedded anchor immediately following the retrieval of the caisson due to weakening of the clay in the vicinity of the anchor. As the clay regains strength with time, the anchor capacity increases to match those of the jacked anchors. The normalised anchor capacity following consolidation agreed well with theoretical solutions. The loss of anchor embedment during the keying...