Pile response due to effective lateral soil movement

2015 ◽  
Vol 52 (6) ◽  
pp. 769-782 ◽  
Author(s):  
L.Z. Wang ◽  
K.X. Chen ◽  
Y. Hong ◽  
C.W.W. Ng

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.


2016 ◽  
Vol 143 ◽  
pp. 475-482 ◽  
Author(s):  
Huu Hung Nguyen ◽  
Hadi Khabbaz ◽  
Behzad Fatahi ◽  
Richard Kelly

1996 ◽  
Vol 33 (4) ◽  
pp. 670-677 ◽  
Author(s):  
H G Poulos ◽  
L T Chen

In this paper, a two-stage analysis involving the finite element method and the boundary element method is used to study pile response due to excavtion-induced lateral soil movements, focusing on unsupported excavations in clay layers. It is shown that the pile response in this case is different from that caused by excavations which are braced. Design charts for estimating pile bending moments and deflections are presented for free-head single piles, and these may be used in practice for assessing the behaviour of existing piles due to the excavation. However, proper account should be taken of the pile head condition, which has been found to have a major effect on the pile bending moment. The application of the charts is demonstrated via a study of a published case history. Comparisons are presented between measured pile behaviour and that predicted both from the chart solutions and the computer analyses, and reasonably good agreement is found between them. Key words: analysis, boundary element, excavation, finite element, pile, soil, movement.


1995 ◽  
Vol 35 (4) ◽  
pp. 85-92 ◽  
Author(s):  
H.G. Poulos ◽  
L.T. Chen ◽  
T.S. Hull

2018 ◽  
Vol 7 (3.18) ◽  
pp. 21
Author(s):  
Lee Lin Jye ◽  
Shenbaga R. Kaniraj ◽  
Siti Noor Linda bt Taib ◽  
Fauzan Bin Sahdi

Soft soil conditions with very soft and deep silty clay have constantly endangered the stability of the riverine and estuarine structures in Sarawak. There have been many failures of jetties, wharves and bridges in Sarawak. In many cases of failures, the piles were not designed to resist the lateral movement, unless they were included to stabilize unstable slopes or potential landslides. This practice may be due to reasons such as erroneously judging the river bank as stable in slope stability analysis or simply due to the inexperience of designers. Also, when the river bank approaches the limiting stability in its natural state any construction activity on the river bank could result in lateral soil movement. This paper highlights this important geotechnical problem in Sarawak. Then it presents the details of a few failures of estuarine structures. A review of situations causing lateral loading of piles is then presented. The results of the in-soil and in-pile displacement measurements are shown in this paper and it is found that the computation made to compare between field and 3D modeling is agreeable.  


2014 ◽  
Vol 580-583 ◽  
pp. 524-531 ◽  
Author(s):  
Lin Li ◽  
Xiao Xin Hu ◽  
Guang Hui Dong ◽  
Ju Liu

Using the explicit finite difference code FLAC3D, the behavior of pile adjacent to braced excavation is investigated. The Modified-cam clay constitutive model was employed to model the non-linear stress-strain soil behavior, and the pile was assumed to have linear elastic behavior. The interface model incorporated in FLAC3D code was used to simulate the soil/pile contact, The built-in 'fish' language was used to calculate the data demanded. The pile response such as pile deflection, bending moment and lateral soil pressure were studied, and it is shown that the pile response is different from that caused by the excavations which are unstructted. In "standard" problem, the effect of different pile head constraints on the pile response was investigated, the effect of lateral displacement of the wall, distance from the excavation face, pile stiffness, pile length and axial load on the pile response are also investigated when the pile head is constrained from deflection. The research finding was compared with other published case history and reasonably good agreement was found between them.


2010 ◽  
Vol 47 (2) ◽  
pp. 180-196 ◽  
Author(s):  
Wei Dong Guo ◽  
H. Y. Qin

An experimental apparatus was developed to investigate the behaviour of vertically loaded free-head piles in sand undergoing lateral soil movement (wf). A large number of tests have been conducted to date. Presented here are 14 typical model pile tests concerning two diameters, two vertical pile loading levels, and varying sliding depths with the movement wf driven by a triangular loading block. Results are provided for driving force as well as for induced shear force (T), bending moment (M), and deflection ( y) along the piles with wf / normalized sliding depth. The tests enable simple expressions to be proposed, drawn from the theory for a laterally loaded pile. The new expressions well capture the evolution of M, T, and y with soil movement observed in current model tests, and the three to five times difference in maximum bending moment (Mmax) from the two modes of loading. They further offer a good estimate of Mmax for eight in situ pile tests and one centrifuge test pile. The study quantifies the sliding resistance offered by a pile for the given wf profiles, pile location (relative to the boundary), and vertical load. It establishes the linear correlation between the maximum thrust (resistance T) and Mmax, regardless of the magnitudes of wf.


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