Rigid pile with a baseplate under large moments: laboratory model evaluations

1996 ◽  
Vol 33 (6) ◽  
pp. 1021-1026 ◽  
Author(s):  
Yenumula VSN Prasad ◽  
T R Chari
Keyword(s):  
Carrying Capacity ◽  
Laboratory Tests ◽  
Model Tests ◽  
Laboratory Model ◽  
Horizontal Load ◽  
Soil Pressure ◽  
Pressure Distributions ◽  
Rigid Pile ◽  
Ultimate Moment ◽  
The Moment

Results of tests on a rigid embedded pile with baseplate are presented. Laboratory tests were conducted with an instrumented 102 mm rigid circular pile embedded in sand and subjected to combined moment and horizontal load. Two different backfills and two different baseplates were used. The rotation of pile and the soil pressure distributions along the length of the pile and at the bottom of the baseplate were measured. It was found that the moment carrying capacity of a rigid pile can be increased between 25 and 50% by using a baseplate. The investigations reported in this paper are useful in the design of directly embedded transmission-pole foundations. Key words:baseplate, model tests, rigid pile, sand, transmission poles, ultimate moment.

Conventional and centrifuge model studies of the moment carrying capacity of short pier foundations in clay

1995 ◽  
Vol 32 (6) ◽  
pp. 976-988 ◽  
Author(s):  
G.J.W. King ◽  
M. Laman
Keyword(s):  
Carrying Capacity ◽  
Three Dimensional ◽  
Model Tests ◽  
Rotational Stability ◽  
Moment Capacity ◽  
Centrifuge Model ◽  
Model Studies ◽  
Saturated Clay ◽  
The Moment ◽  
Centrifuge Model Tests

An experimental investigation into the moment carrying capacity of short rigid pier foundations in saturated clay is described. Scale models of square piers with different breadths and depths were used in both conventional and centrifugal studies. The results show that the relationships between moment and rotation are nonlinear but do not exhibit any peak values, and that moment limits, defined by limiting angular rotations, increase with increases in pier depth and breadth. Empirical equations are derived between moment carrying capacity and pier geometry, for a range of limiting rotations, and a very close fit is demonstrated between the moment–rotation relationships obtained using these equations and the actual data obtained from the model tests. It is shown that, at the same pier rotations, the moment carrying capacities observed in the centrifugal model tests are significantly larger than those in the conventional model tests. Numerical analyses of the prototype geometries were also carried out using a three-dimensional nonlinear finite-element computer program. The results are shown to provide satisfactory agreement with the moment–rotation behaviour and working limits observed in the centrifuge model tests. Thus, even though conventional modelling is usually legitimate for determining the immediate bearing capacity of rigid foundations in saturated clay, their rotational stability is shown to be significantly affected by self-weight stresses. Some of the existing methods for designing short piers subjected to moments are examined and compared with the results from the centrifuge model tests. Key words : pier foundation, clay, moment capacity.

scholarly journals Laboratory Model Tests on Stone Column and Pervious Concrete Columns: A Comparative Study

2021 ◽  
Vol 12 (1) ◽  
pp. 75-89
Author(s):  
Jignesh Patel ◽  
Chandresh Solanki ◽  
Yogendra Tandel ◽  
Bhavin Patel
Keyword(s):  
Carrying Capacity ◽  
Deformation Behavior ◽  
Concrete Columns ◽  
Model Tests ◽  
Pervious Concrete ◽  
Stone Columns ◽  
Stone Column ◽  
Laboratory Model ◽  
Load Carrying Capacity ◽  
Load Carrying

This study aims to perform laboratory model tests to investigate the load-deformation behavior of stone columns (SCs), pervious concrete columns (PCCs), and composite columns (CCs). Here, CC refers to the column which has the upper portion made of PCC and the lower portion made of SC. The parameters investigated in this study include column diameters, column lengths, and installation methods (pre-cast and cast-in-situ methods). The results of the model tests reveal that the axial load-carrying capacity of PCC is nearly 8 times more than that of SC with the same diameter. Moreover, it is also observed that at the top portion of SC, with the PCC length which is about 3.75 to 5 times the column diameter, the load-carrying capacity can significantly increase. It is concluded that the installation methods have marginal influence on the load-deformation behavior of PCC.

Model Tests on Force Characteristics of Reinforced Retaining Wall

2013 ◽  
Vol 353-356 ◽  
pp. 368-373 ◽  
Author(s):  
Hong Bo Zhang ◽  
Jian Qing Wu ◽  
Ying Yong Li ◽  
Xiu Guang Song ◽  
Zhi Chao Xue
Keyword(s):  
Retaining Wall ◽  
Earth Pressure ◽  
Small Deformation ◽  
External Pressure ◽  
Reinforced Soil ◽  
Laboratory Model ◽  
Soil Pressure ◽  
Pressure Distributions ◽  
Lateral Earth Pressure ◽  
Reinforced Retaining Wall

The recent research and development of the reinforced retaining wall is composed of cantilevered reinforced concrete retaining walls which symmetric set on both sides of subgrade and through roadbed width of counter-pulled anchors. The prestressing force can be applied on anchors.The retaining wall has the advantange of high safety, lateral small deformation , wide applicable range and low requirements for the foundation bearing capacity. But due to the lateral restraint of bolt, the soil pressure distributions of retaining wall change a lot. The change will have a significant impact on structures. In order to reveal the reinforced soil retaining wall pressure distributions, laboratory model test was done. The monitoring instruments such as earth pressure cells, anchor rope dynamometers and dial indicators were installed. Research and analysis on the loading process reinforced type soil retaining wall under soil pressure, the lateral earth pressure and anchor rope tension change rule were researched and analysed. The experimental results showed that with the increasing of filling soil height, the retaining wall had a tendency to tilt outward. The basolateral external pressure is larger than the inside pressure. At the same time, anchor tension increased as the top loading increased. Lateral earth pressure distribution is parabolic. Soil pressure around the anchor is larger than other area, the soil arch effect is significant.

Model tests on single piles in soft clay

2000 ◽  
Vol 37 (4) ◽  
pp. 890-897 ◽  
Author(s):  
J L Pan ◽  
A TC Goh ◽  
K S Wong ◽  
C I Teh
Keyword(s):  
Soft Clay ◽  
Model Tests ◽  
Laboratory Model ◽  
Soil Pressure ◽  
Soil Movement ◽  
Pressure Transducers ◽  
Pile Shaft ◽  
Single Piles ◽  
Lateral Soil Movement ◽  
Passive Pile

Laboratory model tests in soft clay were conducted to investigate the behaviour of single piles subjected to lateral soil movements ('passive' pile), and to determine the ultimate soil pressure acting along the pile shaft. A specially designed apparatus for the tests was manufactured and calibrated. Reasonably consistent soil samples were prepared for the tests by a consolidometer. The limiting soil pressures acting along the model pile shaft were measured by pressure transducers. The ultimate soil pressure was then determined based on the maximum value of the limiting soil pressures acting along the pile shaft. The ultimate soil pressure obtained from the single passive pile tests was 10.6su (where su is the undrained shear strength of the clay) and agreed well with those from the literature.Key words: pile, foundation, lateral soil movement, clay, model test.

Numerical Simulation of Pile-Bucket Foundation under Horizontal Load

2012 ◽  
Vol 460 ◽  
pp. 169-174
Author(s):  
Wen Bai Liu ◽  
Liang Yang ◽  
Chen Xia Zhu
Keyword(s):  
Failure Surface ◽  
Horizontal Load ◽  
Soil Pressure ◽  
Passive Region ◽  
Deep Soil ◽  
Maximum Displacement ◽  
Bucket Foundation ◽  
Load Line ◽  
Soil Stress ◽  
Pressure Changes

The pile-bucket foundation is a new kind of foundation. In this paper, the ABAQUS software was used to analyze the soil displacement field and the soil stress field surrounding of the pile-bucket foundation under the multi-cycle horizontal loading. Under the horizontal load, the active area of soil separated from the basics; the passive region takes the shape of a parabolic ring of soil wedge rotate failure surface. The maximum displacement was in the direction of horizontal load line on the surface of soil near the bucket. Horizontal and vertical soil pressure changes are concentrated under the surface of the soil near the bucket, and the maximum horizontal soil stress was in the deep soil around the bucket. There is a point of inflection between 1/3 and 1/2 of the pile into soil , and the soil pressure that upper and lower the point increased in the opposite direction. The horizontal forced resistance of the foundation mainly distributed under the bucket and 1/2 of the pile into soil .The conclusion could provide a reference basis for the analysis of bearing mechanism and destruction characters of pile-bucket foundation

scholarly journals Rigid pile response to cyclic lateral loading: laboratory tests

Géotechnique ◽  
2019 ◽  
Vol 69 (10) ◽  
pp. 863-876 ◽  
Author(s):  
Christelle N. Abadie ◽  
Byron W. Byrne ◽  
Guy T. Houlsby
Keyword(s):  
Laboratory Tests ◽  
Lateral Loading ◽  
Rigid Pile ◽  
Pile Response

scholarly journals PERANCANGAN FONDASI TIANG PANCANG PADA TANAH BERPOTENSI LIKUIFAKSI DI SULAWESI

2020 ◽  
Vol 3 (3) ◽  
pp. 865
Author(s):  
Markus Jusuf ◽  
Aksan Kawanda
Keyword(s):  
Soil Layer ◽  
Cyclic Stress ◽  
Lateral Spreading ◽  
Soil Pressure ◽  
Spreading Effect ◽  
Cyclic Resistance ◽  
Cyclic Resistance Ratio ◽  
Liquefied Soils ◽  
Moment Effect ◽  
The Moment

ABSTRACTIndonesia is a country located in the most active earthquake paths in the world. This makes Indonesia prone to earthquakes and has the potential to experience liquefaction. Liquefaction can cause pile failure, so several things need to be considered in designing piles on potentially liquefied soils. One project in Sulawesi has a profile of uniform grained saturated soil that is susceptible to liquefaction. Two things that need to be considered in the design of piles on potentially liquefied soils is to ignore the capacity of pile friction and calculate the moment due to lateral spreading effects. Calculation of liquefaction potential is done by comparing the ratio of the cyclic stress and the cyclic resistance ratio and is compared by four other methods namely: the Seed et al. (2003), Tsuchida (1970), Seed et al. (2003), and Bray & Sancio (2004). The lateral spreading effect is calculated by referring to the JRA Code where the liquefied soil layer gives pressure to the pile at 30% of the overburden stress and the soil layer above the liquefied soil gives passive soil pressure to the pole. The moment effect caused by lateral spreading results in the addition of dimensions or number of poles.Keywords: liquefaction; lateral spreading; bearing capacity; JRA Code; pile foundationABSTRAKIndonesia adalah negara yang terletak di jalur gempa teraktif di dunia. Hal ini menyebabkan Indonesia rawan gempa dan memiliki potensi untuk mengalami likuifaksi. Likuifaksi dapat menyebabkan kerusakan/kegagalan struktur yang sangat merugikan, sehingga perlu diperhatikan beberapa hal dalam merancang tiang pada tanah berpotensi likuifaksi. Salah satu proyek di Sulawesi memiliki profil tanah pasir berbutir seragam dan jenuh air yang memiliki potensi likuifaksi. Dua hal yang perlu diperhitungkan dalam perancangan tiang pada tanah berpotensi likuifaksi adalah mengabaikan daya dukung friksi tiang dan memperhitungkan momen akibat efek lateral spreading. Perhitungan potensi likuifaksi dilakukan dengan membandingkan rasio tegangan siklik (CSR) dan rasio hambatan siklik (CRR) serta dibandingkan dengan empat metode lainnya yaitu: metode Seed et al. (2003), Tsuchida (1970), Seed et al. (2003), dan Bray & Sancio (2004). Daya dukung aksial pada tiang pancang mengalami pengurangan 32% akibat lapisan tanah yang terlikuifaksi. Efek lateral spreading dihitung dengan acuan JRA Code dimana lapisan tanah terlikuifaksi memberikan tekanan ke tiang sebesar 30% dari tegangan overburden dan lapisan tanah di atas tanah terlikuifaksi memberikan tekanan tanah pasif ke tiang. Efek momen yang diakibatkan oleh lateral spreading mengakibatkan penambahan dimensi ataupun jumlah tiang.Kata kunci: likuifaksi; lateral spreading; daya dukung; JRA Code; fondasi tiang    

The Elastic-Softening Failure of Floating Beams

1988 ◽  
Vol 32 (01) ◽  
pp. 37-43
Author(s):  
Paul C. Xirouchakis
Keyword(s):  
Carrying Capacity ◽  
Maximum Load ◽  
Point Load ◽  
Negative Stiffness ◽  
Load Carrying Capacity ◽  
Perfectly Plastic ◽  
Load Carrying ◽  
Elastic Perfectly Plastic ◽  
The Moment ◽  
Elastic Softening

The solution is presented for an infinite elastic-softening floating beam under a point load. The response depends on two nondimensional parameters: the negative stiffness coefficient that characterizes the descending part of the moment-curvature curve, and the nondimensional softening region half-length. The solution exhibits two important features that the elastic-perfectly plastic solution does not show. First, in certain ranges of parameters, the elastic-softening beam has a clearly defined maximum load carrying capacity. Second, in some other ranges of parameters, the elastic-softening beam has a minimum load or residual strength. The beam stiffens up upon further deformation due to the reactions of the water foundation. Critical softening parameters are calculated that separate stable from unstable behavior.

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