Numerical Investigation of the Installation Process and the Bearing Capacity of Suction Bucket Foundations

Author(s):  
Marc Stapelfeldt ◽  
Julian Bubel ◽  
Jürgen Grabe

This paper was developed in cooperation between the TUHH and Overdick GmbH & Co. KG. The goal of the presented work is gaining further knowledge about the installation and bearing behavior of suction bucket foundations for fixed offshore platforms based on sand. Buckets are usually made of steel and consist of a cylinder and a lid at the top. They are installed into the sea floor by pumping water out of the buckets to create suction, which drives the bucket into the soil. Suction buckets do not require heavy hammer-equipment for construction like common piles. Thus the installation procedure is much faster and protects the environment significantly by avoiding noise emissions. Therefore, suction buckets are to be considered as a serious foundation alternative compared to steel piles. For this paper numerical investigations are performed with the finite analyses software ABAQUS. A total of five finite element models — three for the bearing and two for the installation — were created to carry out parametric studies, while using a hypoplastic constitutive model to describe the soil conditions. Therefore, the buckets diameter, embedded depth and the pore-ratio are to be investigated. In addition three different load conditions are applied in the bearing capacity tests: the maximum vertical load, the maximum horizontal load and the minimum vertical load. During the simulation of the installation procedure different pore ratios are tested and it is attempted to simulate an installation by water-extraction. Based on these numerical investigations it is possible to investigate known and currently more or less unknown phenomena of the bearing and the installation of suction buckets. Thus, a more detailed knowledge about the function of this kind of foundation is to be gained. In addition, the numerical studies are compared to the design-procedure according to API RP-2A-WSD and the DNV CN-30.4.

2014 ◽  
Vol 926-930 ◽  
pp. 597-600
Author(s):  
Xiao Juan Gao ◽  
Yue Hui Li

Based on the theoretical analysis results, the bearing behavior of squeezed and branch pile under vertical load and lateral load was analyzed in this paper. The mean works include the influence of vertical load on the pile lateral bearing capacity and influence of the lateral load on the vertical load bearing capacity. The factors influence the bearing capacity of pile such as elastic modulus of soil around and under pile bottom, pile length, plate position are also analyzed.


2017 ◽  
Vol 11 (1) ◽  
pp. 887-895
Author(s):  
Yuzhuo Wang ◽  
Jian Song ◽  
Cancan Wang ◽  
Chuanguo Fu

Introduction: This paper presents results from a set of numerical studies on the cracked reinforced concrete column at high temperature. Methods: The macroscopic finite element model used in the accounts analysis for high temperature properties of constitutive materials. The validity of the model is established by comparing the predictions from numerical analysis with the data measured in the fire test. Result and Conclusion: Data from the test indicated that the temperature of rebar in column with cracks is 57% ~ 130% higher than that without cracks under the same condition, and different types of crack had significant influence on the bearing capacity of column. These results from parametric studies were utilized to propose ultimate bearing capacity of cracked reinforced concrete column.


2021 ◽  
Vol 11 (20) ◽  
pp. 9446
Author(s):  
Yikang Wang ◽  
Xinjun Zou ◽  
Jianfeng Hu

This paper presents numerical modelling to investigate the bearing capacities and failure mechanisms of single pile-friction wheel composite foundation in sand-overlying-clay soil conditions under combined V-H-M (vertical-horizontal-moment) loadings. A series of detailed numerical models, with validations of centrifuge testing results, are generated to explore the potential factors influencing the bearing capacity of this composite system. Intensive parametric study is then performed to quantify the influences of the foundation geometry, soil properties, sand layer thickness, pre-vertical loading and lateral loading height on the failure envelopes in the V-H-M domain. Last but not least, an empirical design procedure is proposed based on a parametric study to predict the bearing capacity of this composite foundation under various loading conditions, which can provide guidance for its design and application.


2012 ◽  
Vol 446-449 ◽  
pp. 1468-1471
Author(s):  
Wei Li ◽  
Jie Cao ◽  
Rui Hua Zheng

This paper presented the results of centrifuge model tests conducted to investigate the behavior of cohesive soil slopes under the vertical surface load, considering the bolt-shotcrete supported slopes. The cement layer and bolts influenced the behavior of the slope when surface vertical load was applied. The analysis of bearing capacity and displacement threw light on the failure and displacement distribution of the slope.


2021 ◽  
Vol 11 (10) ◽  
pp. 4432
Author(s):  
Jiseong Kim ◽  
Seong-Kyu Yun ◽  
Minsu Kang ◽  
Gichun Kang

The purpose of this study is to grasp the behavior characteristics of a single batter pile under vertical load by performing a model test. The changes in the resistance of the pile, the bending moment, etc. by the slope of the pile and the relative density of the ground were analyzed. According to the results of the test, when the relative density of the ground was medium and high, the bearing capacity kept increasing when the angle of the pile moved from a vertical position to 20°, and then decreased gradually after 20°. The bending moment of the pile increased as the relative density of the ground and the batter angle of the pile increased. The position of the maximum bending moment came closer to the ground surface as the batter angle of the pile further increased, and it occurred at a point of 5.2~6.7 times the diameter of the pile from the ground surface.


Author(s):  
P. C. Lu ◽  
Chen-Ying Wang

Abstract A recent task to design a Rankine-cycle space-power turbine system employing eutectic alloys of alkali metals prompted the present authors to re-examine the NASA design procedure for axial-flow turbines, as outlined by Glassman and Futral (and based on works of Stewart) in 1963. After clarifying the role of the singular case of a single-stage turbine, and organizing the procedure in clear steps, a computer program AXITURB was written. The present paper reports essentially the success of AXITURB in performing parametric studies of NaK and CsK turbines (using 78.4% and 23.1%, respectively, of potassium by weight), after re-generating all the reported NASA designs for turbines employing pure Na, K and Cs. An outline of design steps is also given. AXITURB has been put in public domain. Its heavily commented source code in FORTRAN is available to designers for adaption or modification.


2020 ◽  
Vol 23 (11) ◽  
pp. 2276-2291
Author(s):  
Rui Pang ◽  
Yibo Zhang ◽  
Longji Dang ◽  
Lanbo Zhang ◽  
Shuting Liang

This article proposes a new type of discrete connected precast reinforced concrete diaphragm floor system that consists of precast flat slabs and slab joint connectors. An experimental investigation of discrete connected new-type precast reinforced concrete diaphragm under a vertical distributed static load was conducted, and the effect of slab joint connectors on the load-bearing capacity was evaluated. Then, a finite element analysis of discrete connected new-type precast reinforced concrete diaphragm, precast reinforced concrete floors without slab connectors, and cast-in-situ reinforced concrete floor were performed to understand their working mechanism and determine the differences in load-bearing behavior. The results indicate that the load-bearing capacity and stiffness of discrete connected new-type precast reinforced concrete diaphragm increase considerably as the hairpin and cover plate hybrid slab joint connectors can efficiently connect adjacent precast slabs and enable them to work together under a vertical load by transmitting the shear and moment forces in the orthogonal slab laying direction. The deflection of discrete connected new-type precast reinforced concrete diaphragm in orthogonal slab laying direction is mainly caused by the opening deformation of the slab joint and the rotational deformation of the precast slabs. This flexural deformation feature can provide reference for establishing the bending stiffness analytical model of discrete connected new-type precast reinforced concrete diaphragm in orthogonal slab laying direction, which is vitally important for foundation of the vertical bearing capacity and deformation calculation method. The deflection and crack distribution patterns infer that the discrete connected new-type precast reinforced concrete diaphragm processes the deformation characteristic of two-way slab floor, which can provide a basis for the theoretical analysis of discrete connected new-type precast reinforced concrete diaphragm.


2013 ◽  
Vol 479-480 ◽  
pp. 1185-1189
Author(s):  
Fu Shun Liu ◽  
Wen Wen Chen ◽  
Dong Ping Yang ◽  
Jun Fei Qin ◽  
Zhan Gang Yue ◽  
...  

A new damage assessment method is proposed for aging offshore platforms based on dynamic tests. The stiff nesses of the measured model corresponding to the two measurement moments are estimated by a series of stiffness-correction factors, respectively. Based on these stiffness-correction factors a new damage indicator is defined aiming at reducing influences of existed damages accumulated before the first measurement on damage assessment occurred between the two adjacent measurements. One theoretical improvement is that the requirement using the stiffness matrix of FEM to replace the one of the measured model can be ignored in the calculation of MSE of the measured model. The other development is influences of damages accumulated before the first measurement on damage detection occurs between the two measurements could be reduced greatly, which is very important for aging platforms because these platforms have not been tested aiming at damage detection during their previous service life, especially for most platforms in China. A jacket platform is chosen for numerical studies, and numerical results show that the proposed method could identify damages occurred between the two measurements properly, even including damage severity estimation.


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