Two and three-dimensional resistivity imaging in a shallow coastal sand aquifer

2003 ◽  
Vol 2003 (2) ◽  
pp. 1-4
Author(s):  
Greg Dasey ◽  
Ian Acworth
Keyword(s):  
Three Dimensional ◽  
Resistivity Imaging ◽  
Sand Aquifer ◽  
Coastal Sand

Two-dimensional and three-dimensional resistivity imaging in archaeological site investigation

2006 ◽  
Vol 13 (3) ◽  
pp. 163-181 ◽  
Author(s):  
N. G. Papadopoulos ◽  
P. Tsourlos ◽  
G. N. Tsokas ◽  
A. Sarris
Keyword(s):  
Three Dimensional ◽  
Site Investigation ◽  
Archaeological Site ◽  
Two Dimensional ◽  
Resistivity Imaging

scholarly journals Investigation of a Tertiary maar structure using three-dimensional resistivity imaging

1999 ◽  
Vol 136 (3) ◽  
pp. 771-780 ◽  
Author(s):  
I. Brunner ◽  
S. Friedel ◽  
F. Jacobs ◽  
E. Danckwardt
Keyword(s):  
Three Dimensional ◽  
Resistivity Imaging

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%.

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