Research on the Ultimate Bearing Capacity of Soil about Push-Extend Multi-Under-Reamed Pile at the Compression

2013 ◽  
Vol 718-720 ◽  
pp. 1867-1871
Author(s):  
Yong Mei Qian ◽  
Xue Wen Xie ◽  
Ruo Zhu Wang
Keyword(s):  
Potential Energy ◽  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
The State ◽  
Single Pile ◽  
Friction Resistance ◽  
Theory Of Plasticity ◽  
Side Friction ◽  
Calculating Model

Due to setting of the bearing push-extend reamed of the Push-extend Multi-under-reamed Pile, the stress of soil that the upper and bottom of the bearing push-extend reamed changes at the state of compression. So there are unreasonable parts in the present formula of ultimate bearing capacity of the single pile. The ultimate bearing capacity of the soil around the Push-extend Multi-under-reamed Pile is decided, in the article, according to the failure principle of soil and the theory of sliding line, at the same time, to combine the theory of plasticity potential energy with the principle of imaginary. So the calculating model of calculating end resistance and side friction resistance of pile is corrected and perfected and the up-to-date formula of ultimate bearing capacity of the single pile is put forward at the compression.

Study and Application on Computational Methods for Ultimate Bearing Capacity of Single Pile

2008 ◽  
Vol 400-402 ◽  
pp. 329-334
Author(s):  
Ze Liang Yao ◽  
Zhen Jian ◽  
Guo Liang Bai
Keyword(s):  
Bearing Capacity ◽  
Computational Methods ◽  
Ultimate Bearing Capacity ◽  
Contact Element ◽  
Computational Formula ◽  
Single Pile ◽  
Foundation Design ◽  
Experiment Method ◽  
Contact Element Method ◽  
Element Method

It is difficult and important to accurately calculate single pile ultimate bearing capacity during pile foundation design. Typical computational methods on single pile ultimate bearing capacity are contrastively analyzed in this paper. Contact element method on single pile ultimate bearing capacity is relatively accurate and economical, but it isn’t used in practical projects until now because its computational process is complicated. 343 different single pile ultimate bearing capacities are calculated with the contact element method in order to study a simple computational formula based on the contact element method. All data calculated are analyzed with a linear recursive multi-analysis program which is programmed with Fortran90. A simple computational formula on the contact element method is presented based on the analysis results. The simple computational formula, the experiential formula in the code, the contact element method and the static load experiment method are respectively used to calculate single pile ultimate bearing capacity in two practical projects in order to test the simple computational formula. The results show that the simple computational formula is relatively accurate. Some advice is presented based on the analysis results.

Prediction of Ultimate Bearing Capacity of Half-Screwed Pile by Integrated Exponential Function Model

2013 ◽  
Vol 353-356 ◽  
pp. 881-885
Author(s):  
Jian Xiong Liu ◽  
Yan Yan Gao ◽  
Xiu Hua Li
Keyword(s):  
Bearing Capacity ◽  
Functional Model ◽  
Ultimate Bearing Capacity ◽  
Model Solution ◽  
Least Square ◽  
Single Pile ◽  
Engineering Research ◽  
Exponential Functional ◽  
Practical Engineering ◽  
Difference Form

This study fitted the measured loading-settlement curve of half-screwed pilewith least square model solution of difference form of integrated exponential functional model, and predict ultimate bearing capacity of half-screwed pile according to the fitted curve of maximum curvature point. Combined with practical engineering research, the study explored the feasibility, rationality and limitations of predicting the half-screwed single pile ultimate bearing capacity with least square model solution of difference form of integrated exponential functional model, and provided the theoretical basis for the popularization and application of the half-screwed pile.

Experiment Research on Bored Pile with Post-Grouting Technology

2013 ◽  
Vol 838-841 ◽  
pp. 854-857
Author(s):  
Rui Chao Cheng ◽  
Xin Yu
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Load Test ◽  
Static Load Test ◽  
Pile Head ◽  
Experiment Research ◽  
Friction Resistance ◽  
Bored Pile ◽  
Post Grouting ◽  
Side Friction

The bearing capacity characteristics and side friction characters of post-grouting pile were studied in the static load test which included two piles with post-grouting or not. When the pile head settlements were same, the loads applied on the pile top were used to analyze the bearing properties of post-grouting pile. We got the ultimate side friction of post-grouting pile after fitting test curves of relations between friction resistance and displacement. The tests indicate that both the bearing capacity characteristics and side friction of post-grouting pile are increased in various degrees.

Time Effect Research of Prestressed Pipe Pile Based on High Strain Dynamic Test

2012 ◽  
Vol 256-259 ◽  
pp. 531-534
Author(s):  
Jia Tao Wang ◽  
Hong Li Zhao
Keyword(s):  
Bearing Capacity ◽  
High Strain ◽  
Dynamic Test ◽  
Ultimate Bearing Capacity ◽  
Time Effect ◽  
Load Test ◽  
Single Pile ◽  
Dead Load ◽  
Pipe Pile ◽  
Effect Mechanism

More detailed information about the bearing capacity and integrity of the pile can be obtained by high strain dynamic test than by dead-load test [1]. Engineering examples show that the bearing capacity of the prestressed pipe pile gradually increase with the growth of the resting time, and the ultimate bearing capacity of the pile can reach up to 2 times more than the initial bearing capacity. Through the study of the time effect mechanism, it is found that the increment of ultimate bearing capacity of the single pile is mainly caused by side soil resistance. The end resistance has little influence on the time effect of bearing capacity of pile.

Prediction Method of Vertical Ultimate Bearing Capacity of Single Pile Based on Support Vector Machine

2010 ◽  
Vol 168-170 ◽  
pp. 2278-2282 ◽  
Author(s):  
Yong Jian Liu ◽  
Shi Hua Liang ◽  
Jia Wu Wu ◽  
Na Fu
Keyword(s):  
Support Vector Machine ◽  
Bearing Capacity ◽  
Mechanical Characteristics ◽  
Simple Structure ◽  
Prediction Method ◽  
Ultimate Bearing Capacity ◽  
Support Vector ◽  
Single Pile ◽  
Factors Affecting ◽  
Svm Model

By comprehensively analyzing the main factors affecting vertical ultimate bearing capacity of single pile, a prediction model of Support Vector Machine (SVM), which discusses the nonlinear relationship between vertical ultimate bearing capacity of single pile and influencing factors and analyzes the parameters on the performance of the model through sample knowledge learning, is established in this paper. The research results indicate that, SVM model, which is compared with BP neural networks model, possesses simple structure, flexible adaptability, high precision and powerful generalization ability, and can accurately reflect the actual mechanical characteristics of pile, therefore, SVM is an effective method for predicting vertical ultimate bearing capacity of single pile.

The Research on the Ultimate Bearing Capacity of Soil around the Push-Extend Multi-under-Reamed Pile at Sliding Failure State

2014 ◽  
Vol 578-579 ◽  
pp. 232-235 ◽  
Author(s):  
Yong Mei Qian ◽  
Da Peng Zhao ◽  
Xue Wen Xie
Keyword(s):  
Bearing Capacity ◽  
Failure Mechanism ◽  
Ultimate Bearing Capacity ◽  
Single Pile ◽  
Calculation Formula ◽  
Failure State ◽  
Line Theory

In the paper, the existing unreasonable place of the calculation formula of the bearing capacity of single pile is put forward. Through analyzing the failure mechanism of the soil up and under the Multi-under-reamed, the method for calculating the ultimate bearing capacity of soil around the PEMUR pile can be determined by using the slide-line theory, and the calculation formula of the bearing capacity of single pile of the PEMUR pile is further revised and perfected.

Vertical Loading Test on the Bearing Capacity of Large-Diameter Filling-Piles in the Mudstone and Sandstone Foundation

2013 ◽  
Vol 639-640 ◽  
pp. 587-592 ◽  
Author(s):  
Hui Yang ◽  
Xue Liang Jiang ◽  
Jun Fu
Keyword(s):  
Bearing Capacity ◽  
Load Transfer ◽  
Large Diameter ◽  
Load Test ◽  
Sediment Thickness ◽  
Loading Test ◽  
Friction Resistance ◽  
Vertical Loading ◽  
Pile Diameter ◽  
Side Friction

Based on the vertical loading test results of large-diameter filling pile near an electric factory in the sandstone and mudstone foundation, the load transfer mechanism and vertical loading bearing behavior of the pile were discussed. The analysis shows that the pile mainly behaves as friction piles and the vertical bearing capacity is mainly supplied by side friction resistance. The pile side friction is related to the section displacement of pile, the pile load and the soil characteristic. The pile end resistence is related to pile end settlement, pile diameter, rock-socketed length,rock elasticity modulus of pile end, sediment thickness and pile construction technical. The pile end resistence linearly increases with the settlement of pile end. In tis paper, the dead-load test is recommended in determination the pile bearing capacity and the sediment thickness should be strictly controlled in order to meet the standard. In the intermediary weathered sand-mudstone, the pile end should inset two times of pile diameter for pile whose diameter is 800mm. The pile end should inset 2 meters for pile whose diameter is 1500mm.

Research on Time Effect of Bearing Capacity of Jacked Pile in Soft Soil

2011 ◽  
Vol 403-408 ◽  
pp. 1896-1899
Author(s):  
Jia Tao Wang ◽  
Xiang Hong Song ◽  
Li Wen Zhang
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
Frictional Resistance ◽  
Ultimate Bearing Capacity ◽  
Time Effect ◽  
Single Pile ◽  
Logarithmic Curve ◽  
Side Resistance ◽  
Calculation Results ◽  
Penetration Mechanism

Through the study on the characteristics of bearing capacity of jacked pile in soft soil, it is found that the increment of ultimate bearing capacity of the single pile is mainly determined by pile side resistance. The end resistance has little influence on the time effect of bearing capacity of pile. The relationship between ultimate bearing capacity and time can be expressed with logarithmic curve. According to penetration mechanism of jacked pile, the expansion of a series of spherical cavities in semi-infinite space is used to simulate the process of pile installation. Soil is assumed as Mohr-Coulomb material. Based on the theory of spherical cavity expansion, estimating formulas were proposed to calculate the ultimate side frictional resistance. Then the ultimate bearing capacity of single pile in different time can be obtained. Analyses show that the calculation results are close to the measured data and the error between computed and measured value is little. So it is acceptable for the formula to forecast bearing capacity of jacked piles.

Numerical Simulation Analysis of Bearing Performance of Extra-Long and Large-Diameter Single Pile

2014 ◽  
Vol 1065-1069 ◽  
pp. 943-948
Author(s):  
Zhi Meng Zhao ◽  
Jin Yi Chai ◽  
Cai Xia Fan
Keyword(s):  
Numerical Simulation ◽  
Elastic Modulus ◽  
Bearing Capacity ◽  
Simulation Analysis ◽  
Large Diameter ◽  
Ultimate Bearing Capacity ◽  
Single Pile ◽  
Pile Shaft ◽  
Settlement Ratio ◽  
Pile Length

The effects of pile diameter, the property of pile end bearing stratum, the material parameters of pile shaft and the changes of pile length on the bearing performance of extra-long and large-diameter single pile were examined with the finite element software ABAQUS to make the numerical simulation analysis, by establishing the overall axial symmetry model, which was based on the data of static load test of single pile at the Yellow River Bridge site. The results show that the ultimate bearing capacity of single pile, the stiffness and the end resistance ratio would increase gradually, whereas the compression settlement ratio decreases slowly; the pile end grouting can significantly increase the ultimate loads, and therefore, improve the bearing performance of piles, but it has little effect on the stiffness of pile when loading was smaller; the elastic modulus of pile shaft has no effect on the ultimate bearing capacity of friction piles, little on the end resistance ratio, while the pile compression settlement ratio would gradually decrease and the stiffness would increased with the increase of the elastic modulus of pile shaft, and this increase of stiffness would slow down with the increase of elastic modulus of pile shaft; it is unreasonable to improve the ultimate bearing capacity of extra-long single pile only by means of increasing the pile length.

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