scholarly journals Assessing the Effects of Length, Slope and Distance between Piles on the Bearing Capacity of a Pile Group under Axial Loading in Granular Soil

2017 ◽  
Vol 7 (5) ◽  
pp. 1894-1899
Author(s):  
A. Firoozfar ◽  
A. Rostami ◽  
H. Ghaderi ◽  
H. Zamani ◽  
A. Rostamkhani
Keyword(s):  
Bearing Capacity ◽  
Axial Loading ◽  
Pile Group ◽  
Granular Soils ◽  
Deep Foundations ◽  
Pile Groups ◽  
Finite Element Software ◽  
Bedrock Depth ◽  
Exact Effect ◽  
Technical Capacity

Piles are usually made of steel, concrete, reinforced concrete or wood, used to enhance the ground’s bearing capacity in order to enable the construction of deep foundations, also called pile foundations. However, the exact effect of the complex interaction between the piles and the surrounding soil has not adequately been investigated yet. Considering the increased application of the technique recently, further analysis is essential for achieving the highest economic and technical capacity. Using fewer piles or shorter piles and allowing greater distances between pile groups, results to reduced construction. However, other restrictions such as high groundwater level, bedrock depth and the limited size of the foundation are also to be considered. The issue of optimal pile layout is further investigated in the current paper employing Plaxis, a finite element software, for modeling purposes and considering axial loadings in granular soils. Results are shown and further discussed.

Investigation of Bearing Characteristics of High-Cap Pile Foundation under Inclined Load

2018 ◽  
Vol 777 ◽  
pp. 559-563
Author(s):  
Yu Zhuo Jia ◽  
Guo Zheng Sun ◽  
Chang Qing Li ◽  
Long Long Tian
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Pile Foundation ◽  
Yellow River ◽  
Three Dimensional ◽  
Pile Group ◽  
Element Model ◽  
Inclined Load ◽  
Finite Element Software ◽  
Inclined Angle

To analyze the characteristics of bearing capacity of high-cap pile foundation under inclined load and investigate the influence of vertical and horizontal component on the foundation at different loading angles, based on the background of the Yellow River Crossing project, a three-dimensional finite element model of high-cap foundation is simulated and analyzed with the finite element software ABAQUS. The conclusions are shown as follows: Under the same displacement condition, when the load inclination angle α from 0°(horizontal load) to 80°, the horizontal direction bearing capacity of the foundation increases from 684.8kN to 759.9kN, increases by 10.97%. Expands of vertical load component will affect the pile group effect, the shear force of the back row piles increases with the load inclined angle.

scholarly journals Experimental Investigation on Efficiency Factor of Pile Groups Regarding Distance of Piles

2019 ◽  
Vol 5 (8) ◽  
pp. 1812-1819
Author(s):  
Mojtaba Pashayan ◽  
Gholam Moradi
Keyword(s):  
Axial Loading ◽  
Pile Group ◽  
Group Behavior ◽  
Efficiency Factor ◽  
Diameter Ratio ◽  
Efficiency Coefficient ◽  
Continuous Change ◽  
Pile Groups ◽  
Shaft Resistance ◽  
The Impact

There are a lot of the parameters which affect pile group behavior in soil. One of these factors is the distance of piles from each other. The impact of distance on pile groups in sand has been investigated through some researches, whereas most of them have not represented an exact estimation according to the continuous change of the distance in sand. Moreover, most of previous investigations have considered two piles as a perfect group. Since two-pile group has the least interaction effect among piles, it cannot suitably demonstrate the influence of spacing. In this lecture, several 4-pile groups modeled with different spacing were subjected to axial loading in laboratory. The pile groups were free-head with length to diameter ratio of 13.5. The piles are designed in a way which the shaft resistance of piles can be completely mobilized through the test. Then, the bearing capacities of pile groups are measured and compared with the single pile's resistance in order to calculate the efficiency coefficient of the groups. It is revealed that the distance is noticeably effective in efficiency factor and this effectiveness, non-linearly decreases by increase of spacing. The results show that the efficiency coefficient is changing between almost 1 and 1.4.

Bearing capacity of flexible piles under eccentric and inclined loads in layered soil

1991 ◽  
Vol 28 (6) ◽  
pp. 909-917 ◽  
Author(s):  
A. S. Yalcin ◽  
G. G. Meyerhof
Keyword(s):  
Bearing Capacity ◽  
Pile Group ◽  
Layered Soil ◽  
Pile Groups ◽  
Eccentric Load ◽  
Pile Capacity ◽  
Model Pile ◽  
Inclined Loads ◽  
Experimental Values ◽  
Flexible Model

The bearing capacity of flexible model piles and small pile groups under axial, lateral, and various combinations of eccentric and inclined loads in layered soil consisting of clay overlying sand is investigated. Ultimate pile capacity is found to depend on the eccentricity and inclination of the load and, more significantly, on the ratio of the upper layer thickness to pile embedment. Theoretical estimates based on the concept of effective pile embedment ratio and expressed in terms of equivalent rigid piles agree reasonably well with the experimental values. The behaviour of 2 × 2 flexible model pile groups is observed to be similar to that of single piles. Key words: bearing capacity, piles, flexible pile, pile group, layered soil, sand, clay, eccentric load, inclined load, model pile test.

Nonlinear Numerical Analysis of SRC Frame Middle Joints

2013 ◽  
Vol 376 ◽  
pp. 231-235
Author(s):  
Cheng Li ◽  
Yun Zou ◽  
Jie Kong ◽  
Zhi Wei Wan
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Bearing Capacity ◽  
Axial Load ◽  
Load Ratio ◽  
Experimental Results ◽  
Steel Ratio ◽  
Finite Element Software ◽  
Axial Load Ratio ◽  
Hysteretic Performance

Nonlinear numerical analysis for the force performance of frame middle joint is processed in this paper with the finite element software of ABAQUS. Compared with experimental results, numerical analysis results are found to be reasonable. Then the influence of factors such as shaped steel ratio and axial-load ratio are contrastively analyzed. The results show that shaped steel ratio has a greater influence on the bearing capacity and hysteretic performance of the structure, but the axial-load ratio has less influence.

Bearing Capacity Characteristic of Unsaturated Granular Soils

2011 ◽  
Vol 261-263 ◽  
pp. 989-993 ◽  
Author(s):  
Anuchit Uchaipichat ◽  
Ekachai Man Koksung
Keyword(s):  
Bearing Capacity ◽  
Matric Suction ◽  
Ultimate Bearing Capacity ◽  
Experimental Program ◽  
Granular Soils ◽  
Test Results ◽  
High Level ◽  
Unsaturated Granular Soils ◽  
Capacity Characteristic

An experimental program of laboratory bearing tests was performed to characterize the bearing capacity of foundation on unsaturated granular soils. All tests were performed by pushing a circular rod on the surface of compacted sand specimens with different values of matric suction until failure. The test results show an increase in ultimate bearing capacity with increasing matric suction at low suction value but a decrease in that at high level of suction. The comparisons between the test results and simulations using the expressions proposed in this paper are presented and discussed. Good agreements are achieved for all testing values of suction.

Seismic Response of Pile Groups Improved with Deep Cement mixing Columns in Liquefiable Sand: Shaking Table Tests

2021 ◽  
Author(s):  
Dingwen Zhang ◽  
Anhui Wang ◽  
Xuanming Ding
Keyword(s):  
Seismic Behavior ◽  
Lateral Displacement ◽  
Bending Moment ◽  
Pile Group ◽  
Shaking Table ◽  
Excess Pore Pressure ◽  
Shaking Table Tests ◽  
Pile Groups ◽  
Acceleration Response ◽  
Table Model

A series of shaking table model tests were performed to examine the effects of deep cement mixing (DCM) columns with different reinforcement depths on the seismic behavior of a pile group in liquefiable sand. Due to the DCM column reinforcement, the fundamental natural frequency of the model ground increases noticeably. The excess pore pressure of soils reduces with the increase of reinforcement depths of the DCM columns. Before liquefaction, the acceleration response of soils in the improved cases is obviously lower than that in the unimproved case, but the acceleration attenuation is greater after liquefaction in the unimproved case. Moreover, the lateral displacement of the superstructure, the settlement of the raft, and the bending moment of the piles in the improved cases are significantly reduced compared to those in the unimproved case, and the reduction ratios rise with the increase of reinforcement depth of the DCM columns. However, reinforcement by the DCM columns may result in the variation of the location of the maximum moment that occurs in the pile.

scholarly journals Comparison of Induced Deflection and Forces in Piles Adjacent to Tunnelling and Deep Excavation in 2D and 3D Problems

2018 ◽  
Vol 203 ◽  
pp. 04011
Author(s):  
Ong Yin Hoe ◽  
Hisham Mohamad
Keyword(s):  
Bending Moment ◽  
Pile Group ◽  
3D Models ◽  
Deep Excavation ◽  
Pile Groups ◽  
Out Of Plane ◽  
National University ◽  
Plane Direction ◽  
2D And 3D ◽  
2D Model

There is a trend in Malaysia and Singapore, engineers tend to model the effect of TBM tunneling or deep excavation to the adjacent piles in 2D model. In the 2D model, the pile is modelled using embedded row pile element which is a 1-D element. The user is allowed to input the pile spacing in out-of-plane direction. This gives an impression to engineers the embedded pile row element is able to model the pile which virtually is a 3D problem. It is reported by Sluis (2014) that the application of embedded pile row element is limited to 8D of pile length. It is also reported that the 2D model overestimates the axial load in pile and the shear force and bending moment at pile top and it is not realistic in comparison to 3D model. In this paper, the centrifuge results of single pile and 6-pile group - tunneling problem carried out in NUS (National University of Singapore) are back-analysed with Midas GTS 3D and a 2D program. In a separate case study, pile groups adjacent to a deep excavation is modelled by 3D and 2D program. This paper compares the deflection and forces in piles in 2D and 3D models.

Flexural Bearing Capacity Research of Composite Beams with Edge Constraint Component

2013 ◽  
Vol 639-640 ◽  
pp. 807-811
Author(s):  
Yang Wang ◽  
Tian Li
Keyword(s):  
Bearing Capacity ◽  
Steel Structure ◽  
Composite Beams ◽  
Deformation And Failure ◽  
Finite Element Software ◽  
Composite Frame ◽  
Negative Moment ◽  
Flexural Bearing Capacity ◽  
Simulation Results ◽  
Current Code

To investigate the flexural bearing capacity in negative moment region of composite beams，we examined different ends constraint components. The modeling of the beam ends connected framework has been done by the finite element software ANSYS. The concrete thickness, slab reinforcement ratio and different component at the edge of the composite framework in the negative moment region are taken into account. The performance during the process of deformation and failure are got by nonlinear analysis. The flexural bearing capacity was reported, with the negative moment region of the composite frame beam, it revealed great differences when the beams are different component. Simulation results show that the concrete thickness take the biggest influence on bearing capacity. The results showed the behaviors of the composite frame beams are different with positive moment region, and calculation based on current code for design of steel structure (GB50017-2003) would be a big deviation.

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