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Wei Dong Guo - One of the best experts on this subject based on the ideXlab platform.
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Modeling Single Piles Subjected to Evolving Soil Movement
International Journal of Geomechanics, 2017Co-Authors: Wei Dong Guo, Hongyu Qin, E. H. GheeAbstract:AbstractTo design passive piles, it is critical to incorporate the impact of lateral Soil Movement (ws) and its profiles. This may be conveniently realized by using appropriate input parameters and a three-layer analytical model developed by the first author. In this paper, 25 (1-g) model tests were conducted on single piles in sand, subjected to a uniform (U), inverse triangular (T), or arc (A) profile of sand Movement, to a final sliding depth (lm) of either 0.29l (l = pile embedment) or 0.57l, respectively. The measured response is subsequently simulated using the three-layer model to gain the input parameters and pile–Soil interaction mechanism. The main conclusions (for lm = 0.29l) are as follows. First, the limiting resistance per unit length (at pile-tip level; pb) increases from uniform to inverse triangular and further to arc Movement profiles at an increasing magnitude of ws. These profiles may be superimposed together to mimic evolving Soil Movement profiles. Second, the pb attains 30−60% of th...
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Response of Piles Subjected to Progressive Soil Movement
Geotechnical Testing Journal, 2015Co-Authors: Hongyu Qin, Wei Dong GuoAbstract:Model tests were conducted to investigate the behavior of vertically loaded, free head piles undergoing lateral Soil Movement using an experimental apparatus developed in house. This paper presents ten new tests on an instrumented model pile in dry sand, which provide the profiles of bending moment, shear force and pile deflection along the pile, the development of maximum bending moment Mmax, maximum shear force Tmax, and pile deflection y0 at the ground surface with Soil Movement. The tests reveal the effects of axial load P (at pile head), the distance between the tested pile and source of free Soil Movement Sb, sliding depths, and angle of Soil Movement (via loading angle) on the pile response. For instance, the axial loading P leads to extra bending moment and deflection in the passive pile; the Mmax reduces with increase in Sb; and the Mmax is proportional to the “angle” of Soil Movement. The elastic solution by Guo and Qin [Guo, W. D., Qin, H. Y., 2010, “Thrust and Bending Moment of Rigid Piles Subjected to Moving Soil,” Can. Geotech. J., Vol. 47, No. 2, pp. 180–196] was used to predict the development of Mmax and Tmax observed in the current tests, a boundary element analysis, and an in situ pile test, respectively. It provides satisfactory predictions for all cases against the measured data.
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Group effects of piles due to lateral Soil Movement
2013Co-Authors: Hongyu Qin, Wei Dong GuoAbstract:Laboratory model tests have been conducted to investigate the responses of piles subjected to lateral Soil Movement. The results of a single pile test and four tests on two piles arranged in a row perpendicular to the direction of Soil Movement are presented. The development of maximum bending moment, maximum shear force, and pile deflection with Soil Movement and the largest pile response profiles for the single pile and pile groups are compared. Group effect was evaluated using group factor which is defined in terms of the measured maximum bending moment. The major findings are (1) the pile head conditions (free or capped) are insignificant on piles subjected to lateral Soil Movement when arranged in a row, (2) the group factor decreases as the pile spacing reduces, (3) a linear relationship exists between the maximum bending moment and maximum shear force for both the pile groups and single pile.
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A simplified solution for predicting the response of rigid piles due to lateral Soil Movement
2012Co-Authors: Eng How Ghee, Wei Dong GuoAbstract:ABSTRACT The design of a pile subjected to lateral Soil Movement often requires detail Soil parameters in order to undertake a rational design. While the available design methods are generally based on numerical approaches, the fundamental question to be answered is the relationship between the magnitude of Soil Movement, the pressure profile on the pile shaft, and the way that the load is transferred along the pile shaft. This paper first proposes a relation between the magnitude of Soil Movement and the pressure acting on the pile shaft from the observation of a number of model scale tests reported by the authors. Subsequently, a simplified solution is proposed to analyse a rigid pile subjected to lateral Soil Movement by the mean of calculating the pressure distribution acting along the pile shaft. The simplified solution is able to provide sufficiently accurate means in predicting the bending moment and the shear force profiles from the calculated pressure distribution acting along the pile shaft. Two case studies are presented in order to demonstrate the ability of the simplified solution in predicting the actual pile response. Keywords: rigid pile, lateral Soil Movement, pressure distribution, simplified solution
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Pile responses due to lateral Soil Movement of uniform and triangular profiles
GeoFlorida 2010, 2010Co-Authors: Hongyu Qin, Wei Dong GuoAbstract:Model tests were conducted on vertically loaded single piles in sand subjected to either a uniform or a triangular profile of Soil Movement. Results of four tests are presented herein in the form of maximum bending moment (Mmax), shear force, and pile deflection profiles. The evolution of the pile response with frame Movements is examined, regarding the effects of Soil Movement depth and profiles, and axial load using the measured moment and deflection. In particular, the triangular profile causes 95~160% higher ‘ultimate’ Mmax than the uniform Movement does. The vertical load causes 5~17% higher value of the Mmax.
Ihsan Al-abboodi - One of the best experts on this subject based on the ideXlab platform.
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Experimental investigation of batter pile groups behaviour subjected to lateral Soil Movement in sand
International Journal of Geotechnical Engineering, 2019Co-Authors: Tahsin Toma Sabbagh, Osamah Al-salih, Ihsan Al-abboodiAbstract:A series of laboratory model tests on batter pile groups embedded in the sand was carried out in a specially designed testing box. The lateral responses were investigated for 1 × 2 capped batter pile groups when subjected to lateral Soil Movements (passive loading) with different configurations; Vertical-Vertical (VVL), Batter-Vertical (BVL), Vertical-Batter (VBL), and Both- Batter (BBL). The effect of pile group arrangement and batter angle on the bending moment, shear force, Soil reaction, pile rotation and deflection behaviour of the passive batter pile groups were studied. It is observed that the behaviour of the individual piles in a group was significantly affected by the batter angle and the pile group arrangement. It is also shown that under passive loading, batter pile groups with (BBL) configuration of (−10°, +10°) offered more resistance to the lateral Soil Movement compared to other pile group arrangements, while (VVL) configuration offered the least resistance.
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Model Tests on Single Batter Piles Subjected to Lateral Soil Movement
Research Journal of Applied Sciences Engineering and Technology, 2019Co-Authors: Osamah Al-salih, Tahsin Toma Sabbagh, Wisam Alawadi, Ihsan Al-abboodiAbstract:A series of laboratory tests have been carried out to investigate the lateral response of battered piles under lateral Soil Movement. Model tests were carried out using instrumented rigid aluminium piles. The piles were embedded in homogeneous sand Soil at batter angles &beta = 0°, ±10° and ±20° were subjected to two types of lateral Soil Movement profile. The results obtained from the study are presented in terms of the bending moment, shear force, Soil reaction, pile rotation and lateral deflections along the length of the batter pile. The results of model tests on single vertical and batter piles under horizontal loads showed that the batter angle (&beta) significantly influenced the response of the batter piles. Regardless of the value of sand density, bending moment and deflection with batter angles &beta = +10° or positive batter piles were higher compared then vertical piles and negative batter piles.
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Model tests on piled raft subjected to lateral Soil Movement
International Journal of Geotechnical Engineering, 2017Co-Authors: Ihsan Al-abboodi, Tahsin Toma SabbaghAbstract:Passive loadings due to lateral Soil Movement-induced activities are highly influencing the serviceability and safety of constructions. This research aims to investigate the influence of axial loads, sand density and the depth of moving Soil on the lateral behaviour of piled raft under progressively moving sand. In order to achieve this goal taking into account the complex interaction effects of piles, cap and subSoil, a laboratory apparatus and small scale models have been designed and fabricated carefully to ensure a reasonable simulation of this geotechnical problem. It is found that the above parameters play an important role in the response of piled foundations. The value of Soil displacement at which the measured moment reaches its ultimate value decreases as axial loads increase. Peak displacement of the raft has been found to be a function of Soil density.
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Effects of Axial Loads and Soil Density on Pile Group Subjected to Triangular Soil Movement
World Academy of Science Engineering and Technology International Journal of Environmental Chemical Ecological Geological and Geophysical Engineering, 2017Co-Authors: Ihsan Al-abboodi, Tahsin Toma-sabbaghAbstract:Laboratory tests have been carried out to investigate the response of 2x2 pile group subjected to triangular Soil Movement. The pile group was instrumented with displacement and tilting devices at the pile cap and strain gauges on two piles of the group. In this paper, results from four model tests were presented to study the effects of axial loads and Soil density on the lateral behavior of piles. The responses in terms of bending moment, shear force, Soil pressure, deflection, and rotation of piles were compared. Test results indicate that increasing the Soil strength could increase the measured moment, shear, Soil pressure, and pile deformations. Most importantly, adding loads to the pile cap induces additional moment to the head of frontpile row unlike the back-pile row which was influenced insignificantly.
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Modelling the Response of Single Passive Piles Subjected to Lateral Soil Movement using PLAXIS
International journal of engineering research and technology, 2015Co-Authors: Ihsan Al-abboodi, Tahsin Toma-sabbagh, Ali Al-jazaairryAbstract:Response of single pile subjected to lateral displacements of Soil mass using 3D finite element software (PLAXIS) is studied. Embedded pile feature in which the pile composed of beam elements with special interface elements to represent pile-Soil interaction is used. The Mohr–Coulomb elastic–plastic constitutive model was employed for the Soil stress-strain behaviour. A good agreement between laboratory and predicted results is observed in the validation analysis. A parametric study was conducted to investigate the influence of Soil Young's modulus and Soil Movement profile on the response of single "passive pile". The software results revealed that the distribution of bending moment along the pile length vary considerably and was in a very good agreement with the real pile behaviour when adopting a variation of Soil elastic modulus with depth instead of choosing a constant value.
Hongyu Qin - One of the best experts on this subject based on the ideXlab platform.
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Modeling Single Piles Subjected to Evolving Soil Movement
International Journal of Geomechanics, 2017Co-Authors: Wei Dong Guo, Hongyu Qin, E. H. GheeAbstract:AbstractTo design passive piles, it is critical to incorporate the impact of lateral Soil Movement (ws) and its profiles. This may be conveniently realized by using appropriate input parameters and a three-layer analytical model developed by the first author. In this paper, 25 (1-g) model tests were conducted on single piles in sand, subjected to a uniform (U), inverse triangular (T), or arc (A) profile of sand Movement, to a final sliding depth (lm) of either 0.29l (l = pile embedment) or 0.57l, respectively. The measured response is subsequently simulated using the three-layer model to gain the input parameters and pile–Soil interaction mechanism. The main conclusions (for lm = 0.29l) are as follows. First, the limiting resistance per unit length (at pile-tip level; pb) increases from uniform to inverse triangular and further to arc Movement profiles at an increasing magnitude of ws. These profiles may be superimposed together to mimic evolving Soil Movement profiles. Second, the pb attains 30−60% of th...
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Response of Piles Subjected to Progressive Soil Movement
Geotechnical Testing Journal, 2015Co-Authors: Hongyu Qin, Wei Dong GuoAbstract:Model tests were conducted to investigate the behavior of vertically loaded, free head piles undergoing lateral Soil Movement using an experimental apparatus developed in house. This paper presents ten new tests on an instrumented model pile in dry sand, which provide the profiles of bending moment, shear force and pile deflection along the pile, the development of maximum bending moment Mmax, maximum shear force Tmax, and pile deflection y0 at the ground surface with Soil Movement. The tests reveal the effects of axial load P (at pile head), the distance between the tested pile and source of free Soil Movement Sb, sliding depths, and angle of Soil Movement (via loading angle) on the pile response. For instance, the axial loading P leads to extra bending moment and deflection in the passive pile; the Mmax reduces with increase in Sb; and the Mmax is proportional to the “angle” of Soil Movement. The elastic solution by Guo and Qin [Guo, W. D., Qin, H. Y., 2010, “Thrust and Bending Moment of Rigid Piles Subjected to Moving Soil,” Can. Geotech. J., Vol. 47, No. 2, pp. 180–196] was used to predict the development of Mmax and Tmax observed in the current tests, a boundary element analysis, and an in situ pile test, respectively. It provides satisfactory predictions for all cases against the measured data.
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Group effects of piles due to lateral Soil Movement
2013Co-Authors: Hongyu Qin, Wei Dong GuoAbstract:Laboratory model tests have been conducted to investigate the responses of piles subjected to lateral Soil Movement. The results of a single pile test and four tests on two piles arranged in a row perpendicular to the direction of Soil Movement are presented. The development of maximum bending moment, maximum shear force, and pile deflection with Soil Movement and the largest pile response profiles for the single pile and pile groups are compared. Group effect was evaluated using group factor which is defined in terms of the measured maximum bending moment. The major findings are (1) the pile head conditions (free or capped) are insignificant on piles subjected to lateral Soil Movement when arranged in a row, (2) the group factor decreases as the pile spacing reduces, (3) a linear relationship exists between the maximum bending moment and maximum shear force for both the pile groups and single pile.
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Pile response due to effective lateral Soil Movement
2010Co-Authors: Hongyu Qin, Weidong Dong GuoAbstract:Extensive model tests have been performed to investigate the response of piles subjected to lateral Soil Movement. This paper discusses the effect of source of lateral (effective) Soil Movement on the behavior of a single pile. The pile was installed at three locations to the loading side where lateral Soil Movement was generated by using a triangular or rectangular loading block to simulate corresponding Soil Movement profiles. The test results are presented in terms of the development of maximum bending moment, maximum shear force and pile deflection at ground surface with Soil Movement and their distribution along the pile with depth. The effect of the distance on the maximum bending moment is presented and can be well captured by the effective frame Movement. This is shown by the calculation using simple solutions.
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Pile responses due to lateral Soil Movement of uniform and triangular profiles
GeoFlorida 2010, 2010Co-Authors: Hongyu Qin, Wei Dong GuoAbstract:Model tests were conducted on vertically loaded single piles in sand subjected to either a uniform or a triangular profile of Soil Movement. Results of four tests are presented herein in the form of maximum bending moment (Mmax), shear force, and pile deflection profiles. The evolution of the pile response with frame Movements is examined, regarding the effects of Soil Movement depth and profiles, and axial load using the measured moment and deflection. In particular, the triangular profile causes 95~160% higher ‘ultimate’ Mmax than the uniform Movement does. The vertical load causes 5~17% higher value of the Mmax.
Yean Khow Chow - One of the best experts on this subject based on the ideXlab platform.
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Closure to “Behavior of Pile Groups Subject to Excavation-Induced Soil Movement in Very Soft Clay” by D. E. L. Ong, C. F. Leung, and Y. K. Chow
Journal of Geotechnical and Geoenvironmental Engineering, 2011Co-Authors: Dominic Ek Leong Ong, Chun Fai Leung, Yean Khow ChowAbstract:Closure to D. E. L. Ong, C. F. Leung, and Y. K. Chow (2009). Behavior of pile groups subject to excavation-induced Soil Movement in very soft clay. Journal of Geotechnical and Geoenvironmental Engineering, 135 (10). For the original article, see: http://hdl.handle.net/1959.3/6868
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Behavior of Pile Groups Subject to Excavation-Induced Soil Movement in Very Soft Clay
Journal of Geotechnical and Geoenvironmental Engineering, 2009Co-Authors: Dominic Ek Leong Ong, Chun Fai Leung, Yean Khow ChowAbstract:A series of centrifuge model tests was conducted to investigate the behavior of pile groups of various sizes and configurations behind a retaining wall in very soft clay. With a 1.2-m excavation in front of the wall, which may simulate the initial stage of an excavation prior to strutting, the test results reveal that the induced bending moment on an individual pile in a free-head pile group is always smaller than that on a corresponding single pile located at the same distance behind the wall. This is attributed to the shadowing and reinforcing effects of other piles within the group. The degree of shadowing experienced by a pile depends on its relative position in the pile group. With a capped-head pile group, the individual piles are forced to interact in unison though subjected to different magnitudes of Soil Movement. Thus, despite being subjected to a larger Soil Movement, the induced bending moment on the front piles is moderated by the rear piles through the pile cap. A finite element program developed at the National University of Singapore is employed to back-analyze the centrifuge test data. The program gives a reasonably good prediction of the induced pile bending moments provided an appropriate modification factor is applied for the free-field Soil Movement and the amount of restraint provided by the pile cap is properly accounted for. The modification factor applied to the free-field Soil Movement accounts the reinforcing effect of the piles on the Soil Movement.
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Behavior of Pile Groups Subject to Excavation-Induced Soil Movement
Journal of Geotechnical and Geoenvironmental Engineering, 2003Co-Authors: Chun Fai Leung, J. K. Lim, R. F. Shen, Yean Khow ChowAbstract:Centrifuge model tests have been conducted on free-head and capped-head pile groups consisting of two, four, and six piles located adjacent to an unstrutted deep excavation in sand. It is found that when two free- or capped-head piles are arranged in a row parallel to the retaining wall, the interaction effect between piles is insignificant. When two piles are arranged in a line perpendicular to the wall, the existence of a front pile would reduce the detrimental effect of excavation-induced Soiled Movement on the rear pile. In addition, the provision of a pile cap for two piles arranged in a line would exert a significant influence on the behavior of the pile group. For free-head four- or six-pile groups, the induced bending moment decreases as the number of piles increases. Moreover, the interior piles of the pile group always experience lower bending moments than those of peripheral piles as the latter have more exposure to the excavation-induced Soil Movement and are thus more adversely affected. For the capped-head four- or six-pile groups, it can be established that the provision of a pile cap would help to moderate the pile-group deflection against Soil Movement as the rear piles, that are located farther away from the wall and thus less affected by the Soil Movement, would drag the front piles back.
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Behavior of Pile Subject to Excavation-Induced Soil Movement
Journal of Geotechnical and Geoenvironmental Engineering, 2000Co-Authors: Chun Fai Leung, Yean Khow Chow, R. F. ShenAbstract:This paper presents the results of centrifuge model tests on unstrutted deep excavation in dense sand and its influence on an adjacent single pile foundation behind the retaining wall. It is found that, in the case of a stable wall, the induced pile bending moment and deflection decrease exponentially with increasing distance between the pile and the wall. Pile head boundary condition plays an important role in affecting the pile responses due to an adjacent excavation. In the case of retaining wall collapse, the failure pattern of the Soil behind the wall features a slip plane projecting from near the wall toe to the ground surface. Soil within the failure zone demonstrates large lateral Movement and induces significant bending moment and deflection on pile located within the zone. Soil Movement and pile responses outside this zone are noted to be significantly less. A comparison between the experimental results and the theoretical predictions by an existing numerical method shows good agreement, provided that appropriate assumptions are made on the Soil parameters and conditions, especially in the case of retaining wall collapse.
Eng How Ghee - One of the best experts on this subject based on the ideXlab platform.
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A simplified solution for predicting the response of rigid piles due to lateral Soil Movement
2012Co-Authors: Eng How Ghee, Wei Dong GuoAbstract:ABSTRACT The design of a pile subjected to lateral Soil Movement often requires detail Soil parameters in order to undertake a rational design. While the available design methods are generally based on numerical approaches, the fundamental question to be answered is the relationship between the magnitude of Soil Movement, the pressure profile on the pile shaft, and the way that the load is transferred along the pile shaft. This paper first proposes a relation between the magnitude of Soil Movement and the pressure acting on the pile shaft from the observation of a number of model scale tests reported by the authors. Subsequently, a simplified solution is proposed to analyse a rigid pile subjected to lateral Soil Movement by the mean of calculating the pressure distribution acting along the pile shaft. The simplified solution is able to provide sufficiently accurate means in predicting the bending moment and the shear force profiles from the calculated pressure distribution acting along the pile shaft. Two case studies are presented in order to demonstrate the ability of the simplified solution in predicting the actual pile response. Keywords: rigid pile, lateral Soil Movement, pressure distribution, simplified solution
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behavior of axially loaded pile groups subjected to lateral Soil Movement
Foundation Analysis and Design: Innovative Methods, 2006Co-Authors: Eng How GheeAbstract:Response of a pile due to lateral Soil Movement and axial load has been investigated extensively by the authors. Typical results deduced from single pile tests in sand are presented previously in terms of effect of pile diameter, Soil Movement profile, sliding depth and magnitude of axial load. In this paper, a brief description of the apparatus was presented. Results from two model tests were reported, which were conducted on two instrumented pile groups embedded in sand subjected to a uniform lateral Soil Movement at a sliding depth of 0.57 L ( L = pile embedment length). Analysis revealed the effect of the direction and depth of Soil Movement, together with the magnitude of axial load, which are illustrated via profiles of bending moment, shear force, Soil reaction, and pile deflection along instrumented piles in groups at various stages.
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Effect of Soil Movement profiles on vertically loaded single pile
2006Co-Authors: Wei Dong Guo, Hongyu Qin, Eng How GheeAbstract:The behavior of a free head pile in sand under a combined lateral Soil Movement and vertical load was investigated using a newly developed experimental apparatus. Four instrumented pile tests are presented to compare the effect of Soil Movement profiles of an arc and rectangular shape on the response of the pile. It was found that (1) effect of Soil Movement profiles is significant; (2) Vertical load at the pile head leads to additional bending moment, and alteration of the pile-Soil interaction mode. 1 INSTRUCTION Quite a few publications are available concerning response of piles subjected to vertical loads, and Soil Movements, respectively. Especially, in regard to that due to Soil Movement, experimental study has been conducted previously in light of centrifuge modeling
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Response of axially loaded pile groups subjected to lateral Soil Movement - An expremental investigation
Tall Buildings, 2005Co-Authors: Wei Dong Guo, Eng How GheeAbstract:A new experimental apparatus has been developed, which allows lateral Soil Movements and vertical load to be applied simultaneously on a pile. A number of tests have been undertaken, which offer consistent results. In this paper, a brief description of the apparatus was presented. Results from two model tests were reported, which were conducted on two instrumented pile groups embedded in sand subjected to uniform lateral Soil Movement. Preliminary analysis indicated that the increase in bending moment, shear force, Soil reaction and the change of pile deflection mode due to axial load on the pile groups
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Response of free-head piles due to lateral Soil Movement
2004Co-Authors: Wei Dong Guo, Eng How GheeAbstract:Summary: A number of numerical approaches have been developed to predict response of piles due to lateral Soil Movement. Recently a correlation between an ‘equivalent load’ and the magnitude of Soil Movement has been established by the first author, which allows the response of piles due to Soil Movement to be analysed readily using the solutions developed for laterally loaded piles. The accuracy of either prediction is dependent on ‘good’ selection of input parameters, such as the limiting force profile between the pile and Soil mobilised that may vary from case to case. Therefore, it is necessary to investigate this profile before any reliable predictions can be made. This paper attempts to back-figure the profile using a closed-form solution against measured response of three piles. It was found that the back-figured profile for each pile is generally consistent with that suggested for laterally loaded piles. INTRODUCTION Piles may be used to provide lateral resistance against Soil Movement. These piles are known as passive piles, and commonly found stabilizing a sliding slope, supporting bridge abutments, and providing a lateral pressure barrier adjacent to a pile driving or an excavation operation. Design of the passive piles often requires a limiting force profile between the pile and Soil that is not yet available, but has been based on a certain proportion of the profile developed for a lateral loading pile. It is not clear how this usage affects the prediction, as the profile may vary with the amount of Soil Movement, and pile-Soil relative stiffness etc. Such an effect may be examined by back estimation through comparison between measured and predicted response of piles using a closed form solution (Guo, 2003). The close-form solution was recently established for an elastic-plastic Soil (Guo, 2002, 2003), by simulating the pile-Soil interaction as a series of independent springs acting along the shaft and at the pile base. The coupled effect among the springs is also accounted for by introducing a membrane (Guo and Lee, 2001). The elastic-plastic solution for the pile under lateral loading provides sufficiently accurate means in comparison with some existing numerical results, in terms of predicting the bending moment, shear force, deflection and rotation response of the pile. The major advantage of the closed-form solution is that it allows a unique limiting force profile (a key parameter) to be back-estimated, which has been conventionally determined using empirical or semi-empirical relationships derived from field or laboratory test results. For passive piles, the effect of Soil Movement of the unstable layer can be converted to an equivalent load on the piles (Guo, 2003), so that the response of the piles can be predicted using the closed form solution. However, no rigorous guidelines have yet been provided for determining the limiting force profile. This paper provides a preliminary investigation on such profiles based on three recorded cases of measured pile response.