Centrifuge Tests on Installation of Suction Anchors in Soft Clay

2003 ◽  
Author(s):  
Knut H. Andersen ◽  
Philippe Jeanjean ◽  
Dirk Luger ◽  
Hans Petter Jostad
Keyword(s):  
Soft Clay ◽  
Centrifuge Tests

Dynamic Centrifuge Tests of Soft Clay Reinforced by Soil–Cement Grids

2016 ◽  
Vol 142 (7) ◽  
pp. 04016027 ◽  
Author(s):  
Mohammad Khosravi ◽  
Ross W. Boulanger ◽  
Shuji Tamura ◽  
Daniel W. Wilson ◽  
C. Guney Olgun ◽  
...  
Keyword(s):  
Soft Clay ◽  
Centrifuge Tests ◽  
Soil Cement

scholarly journals Dynamic centrifuge tests of structures with shallow foundations on soft clay reinforced by soil-cement grids

2017 ◽  
Vol 57 (4) ◽  
pp. 501-513 ◽  
Author(s):  
Mohammad Khosravi ◽  
Ross W. Boulanger ◽  
Daniel W. Wilson ◽  
C. Guney Olgun ◽  
Shuji Tamura ◽  
...  
Keyword(s):  
Soft Clay ◽  
Shallow Foundations ◽  
Centrifuge Tests ◽  
Soil Cement

Effect of consolidation on responses of a single pile subjected to lateral soil movement

2015 ◽  
Vol 52 (6) ◽  
pp. 769-782 ◽  
Author(s):  
L.Z. Wang ◽  
K.X. Chen ◽  
Y. Hong ◽  
C.W.W. Ng
Keyword(s):  
Soft Clay ◽  
Bending Moment ◽  
Coefficient Of Consolidation ◽  
Construction Period ◽  
Soil Movement ◽  
Centrifuge Tests ◽  
Short Period ◽  
Lateral Soil Movement ◽  
Pile Response ◽  
Pile Length

Given extensive research carried out to study pile response subjected to lateral soil movement in clay, the effect of consolidation on the pile–soil interaction is rarely considered and systematically investigated. For this reason, four centrifuge tests were conducted to simulate construction of embankment adjacent to existing single piles in soft clay, considering two typical drainage conditions (i.e., drained and undrained conditions) and two typical pile lengths (i.e., relatively long pile and short pile). The centrifuge tests were then back-analyzed by three-dimensional coupled-consolidation finite element analyses. Based on reasonable agreements between the two, numerical parametric studies were conducted to systematically investigate and quantify the influence of construction rate and pile length on pile response. It is revealed that by varying drainage conditions, the piles respond distinctively. When the embankment is completed within a relatively short period (cvt/d2 < 2, where cv, t, and d denote the coefficient of consolidation, construction period, and pile diameter, respectively), the pile located adjacent to it deforms laterally away from the embankment. Induced lateral pile deflection (δ) and bending moment reduce with construction period. On the contrary, embankment constructed within a relatively long period (cvt/d2 > 200) leads the pile to deform laterally towards the embankment, with δ and bending moment increases with construction period. By halving the length of pile embedded in the drained ground, the maximum induced bending moment (BMmax) was slightly reduced (by 23%). On the other hand, shortening the length of the pile in the undrained ground is much more effective in reducing BMmax, i.e., halving pile length resulting in 78% reduction in bending moment. A new calculation chart, which takes various drainage conditions and pile lengths into account, was developed for estimation of BMmax.

scholarly journals Recent centrifuge modelling of offshore geotechnical problems at IWHR

2019 ◽  
Vol 92 ◽  
pp. 17001
Author(s):  
Jianhui Liang ◽  
Xianhui Song
Keyword(s):  
Hydraulic System ◽  
Soft Clay ◽  
Laser Scanner ◽  
Vertical Movement ◽  
Test Results ◽  
Centrifuge Modelling ◽  
Soil Stiffness ◽  
Centrifuge Tests ◽  
Load Cells ◽  
Geotechnical Problems

Centrifuge modelling has been proven to be an efficient and reliable approach for examining offshore geotechnical problems. This study reports the two series of centrifuge tests to understand the behaviour of spudcan penetration in a “soft-stiff-soft clay” stratigraphy and the behaviour of gravity anchor subjected to a lateral loading. A hydraulic system has been adopted to apply the large compressive and tensional load on the spudcan and gravity anchor, respectively. Load cells were installed on the base of the spudcan to directly measure the stress acting on the spudcan base. A 2D laser scanner was adopted to monitor the horizontal, vertical movement and tilting of the gravity anchor. The influence of the relative soil stiffness on the spudcan pentration behaviour and the soil deformation and interaction with the gravity anchor are discussed based on the centrifuge test results.

scholarly journals Capacity of Short Piles and Caissons in Soft Clay from Geotechnical Centrifuge Tests

2019 ◽  
Vol 145 (10) ◽  
pp. 04019079 ◽  
Author(s):  
Madhuri Murali ◽  
Francisco J. Grajales-Saavedra ◽  
Ryan D. Beemer ◽  
Charles P. Aubeny ◽  
Giovanna Biscontin
Keyword(s):  
Soft Clay ◽  
Geotechnical Centrifuge ◽  
Centrifuge Tests

scholarly journals A plasticity model for spudcan foundations in soft clay

2014 ◽  
Vol 51 (6) ◽  
pp. 629-646 ◽  
Author(s):  
Youhu Zhang ◽  
Mark J. Cassidy ◽  
Britta Bienen
Keyword(s):  
Finite Element ◽  
Load Capacity ◽  
Soft Clay ◽  
Plasticity Model ◽  
Vertical Load ◽  
Geotechnical Centrifuge ◽  
Centrifuge Tests ◽  
Model Components ◽  
Jack Up ◽  
Selection Of

A plasticity model for predicting the load displacement behaviour of a typical spudcan foundation for offshore jack-up platforms under combined vertical, horizontal, and moment loading in soft clay is presented. Results from geotechnical centrifuge experiments of a spudcan embedded vertically to 0.7, 1.0, and 1.45 footing diameters are described. Augmented with finite element results, these centrifuge experiments are used to evaluate the plasticity model components. As a result of soil backflow on top of the spudcan, enhanced combined bearing capacity was measured and this is reflected in increased yield surface size. A tensile vertical load capacity is also incorporated. The excellent predictive capabilities of the model are demonstrated by retrospectively simulating a selection of centrifuge tests.

Dynamic Centrifuge Tests on Soft Clay Reinforced by Soil-Cement Grids

IFCEE 2015 ◽  
2015 ◽  
Author(s):  
Mohammad Khosravi ◽  
Shuji Tamura ◽  
Ross W. Boulanger ◽  
Daniel W. Wilson ◽  
C. Guney Olgun ◽  
...  
Keyword(s):  
Soft Clay ◽  
Centrifuge Tests ◽  
Soil Cement

Base stability of multi-propped excavations in soft clay subjected to hydraulic uplift

2013 ◽  
Vol 50 (2) ◽  
pp. 153-164 ◽  
Author(s):  
Y. Hong ◽  
Charles W.W. Ng
Keyword(s):  
Soft Clay ◽  
Three Dimensional ◽  
Hydraulic Pressure ◽  
Ground Settlement ◽  
Overburden Pressure ◽  
Passive Resistance ◽  
Centrifuge Tests ◽  
Sand Aquifer ◽  
Base Stability ◽  
Three Dimensional Finite Element

Excavations in soft clay underlain with an aquifer may be destabilized by hydraulic uplift. Previous studies on this subject are based mainly on field observations. Dewatering from the aquifer is a common method to improve base stability where ground settlement is not a major concern. Alternatively, piles readily installed as part of the top-down construction method for multi-propped excavation may be considered to provide base stability and minimize ground settlement outside the excavation. This paper presents results from two centrifuge tests that were conducted to simulate multi-propped excavations in-flight (with and without piles) in soft clay destabilized by hydraulic pressure from an underlying sand aquifer. Moreover, coupled three-dimensional finite element analyses were carried out to back-analyse the centrifuge tests. Numerical parametric studies were also conducted to study the influence of pile length on the effectiveness of base stabilization. It is revealed that both for excavations with and without piles, the artesian pressure required to initiate uplift inside the excavation is about 1.2 times the overburden pressure of the clay. By using “anti-uplift” piles inside the excavation, the ultimate hydraulic uplift resistance increases by 16%, while the uplift movement can be reduced by 80%. The presence of piles also increases the passive resistance in front of the wall by 70%, but reduces the mobilized undrained shear strength, cu, of clay by 53%.

Sign in / Sign up

Export Citation Format

Share Document