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.

Computation of Jacked Pipe Pile Side Resistance Based on Time Effect

2011 ◽  
Vol 368-373 ◽  
pp. 2657-2660
Author(s):  
Jia Tao Wang
Keyword(s):  
Bearing Capacity ◽  
Early Period ◽  
Field Tests ◽  
Frictional Resistance ◽  
Ultimate Bearing Capacity ◽  
Time Effect ◽  
Soil Resistance ◽  
Computing Model ◽  
Logarithmic Curve ◽  
Side Resistance

In the re-pressed tests of jacked pipe piles in soft clay, it was observed that the re-pressed starting pressure can reach to more than 2.5 times of the final pressure for 25 days after finishing the installation; and it increased more rapidly in early period than later. 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. According to the simulation result of the test data, the relationship between pile side resistance and time can be described with logarithmic curve. By this new computing model, the side frictional resistance in different resting time can be obtained, and then the ultimate bearing capacity. It is proved that this method is feasible because the values of side soil resistance calculated by the computing model with software are well consistent with the field tests results.

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.

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.

scholarly journals Calculation of Ultimate Bearing Capacity of Pile Foundations of Highway Bridges under the Coupling of Steep Slope and Karst

2020 ◽  
Vol 198 ◽  
pp. 02017
Author(s):  
Zhongju Feng ◽  
Shaofen Bai ◽  
Wu Min ◽  
Jingbin He ◽  
Zhouyi Huang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Highway Bridges ◽  
Ultimate Bearing Capacity ◽  
Steep Slope ◽  
Karst Area ◽  
Correction Coefficient ◽  
Finite Element Software ◽  
Calculation Results ◽  
Vertical Bearing

In order to study the influence of steep slope-karst coupling on the vertical bearing characteristics of pile foundation, the orthogonal simulation tests of pile foundation under 4 different roof thickness and 5 different slope are carried out by using Marc finite element software, and the correction coefficient of vertical partial bearing capacity of pile foundation according to roof thickness and slope is put forward. The test results show that when the thickness of the roof is more than 3 times the pile diameter, the ultimate bearing capacity of the pile foundation tends to be stable, and the value is about 19% when the slope is 45°; the ultimate bearing capacity of the pile foundation decreases gradually with the increase of the slope, and the reduction reaches 29.83% when the slope is greater than 45°. According to the calculation results, the variation law of vertical partial bearing capacity of pile foundation is analyzed, and the calculation formula of standard value of vertical ultimate bearing capacity of pile foundation in steep slope karst area considering both roof thickness and slope is put forward, and the correction coefficients αi and β are put forward.

Analysis of Uniaxial Dynamic Performance of Concrete-Filled Square Steel Tube Composite Column

2011 ◽  
Vol 94-96 ◽  
pp. 220-224 ◽  
Author(s):  
Xi Guang Cui ◽  
Hai Dong Xu
Keyword(s):  
Strain Rate ◽  
Bearing Capacity ◽  
Dynamic Performance ◽  
Concrete Strength ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Element Analysis ◽  
Compression Performance ◽  
Calculation Results ◽  
Square Steel Tube

Considering the strain rate then puts forward the modified uniaxial dynamic constitutive model related to strain rate in concrete-filled square steel tube and the modified calculation results match well with the experimental results. Based on the above conclusion, uniaxial compression performance finite element analysis with different strain rate among 10-5/s–10-3/s is completed, the results showed that strain rate can obviously change the dynamic performance of the concrete-filled square steel tube. Through the analysis of the influencing factors of the core concrete compressive strength, it is showed that with the increasing of the strain rate and the improving of concrete strength, the ultimate bearing capacity of concrete-filled square steel tube is higher and the ductility is reduced. With the increasing of stirrup ratio, ultimate bearing capacity is greater and the ductility is enhanced. With the sectional dimensions increasing, the ultimate bearing capacity is greater and the ductility is enhanced.

Analyzing on Bearing Performance Influence Factors of Step Cross-Section Pipe Pile

2015 ◽  
Vol 744-746 ◽  
pp. 432-436
Author(s):  
Jie Liu ◽  
Fu An Huang ◽  
Qing Guang Yang ◽  
Bin Cui
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Soft Soil ◽  
Influence Factors ◽  
Single Pile ◽  
Variable Cross ◽  
Obvious Effect ◽  
Pipe Pile ◽  
Geological Conditions ◽  
Hard Soil

In order to improve the bearing behavior and the bearing capacity of single pipe pile, the technology of step cross-section pipe-pile is proposed.Based on FLAC3D, the finite difference model of the pile-soil interaction established,bearing behaviors of step cross-section pipe pile and unimate cross-section pipe pile is studied comparatively and bearing performance influence factors of step cross-section pipe pile is discussed.The results show that the bearing capacity of step cross-section pipe pile is much higher than unimate cross-section pipe pile in the same geological conditions and material dosage. For layered foundation, the bearing capacity of single pile may be improved by setting variable cross-section pile joint in relatively hard soil. But the depth of joint embedded in hard soil has little influence on bearing capacity of single pile.There is an obvious effect on increasing capacity of single pile by improving soil properties of soft soil surrounding pile.

scholarly journals KOMPARASI KINERJA ALAT PILE DRIVING ANALYZER DAN SOFTWARE CAPWAP DALAM MENGHASILKAN DAYA DUKUNG ULTIMIT PONDASI TIANG

2020 ◽  
Vol 28 (3) ◽  
pp. 378
Author(s):  
Rasdinanta Tarigan
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Soft Soil ◽  
Performance Comparison ◽  
Ultimate Bearing Capacity ◽  
Pile Foundations ◽  
Pile Driving ◽  
Analysis Program ◽  
Wave Analysis ◽  
The Difference

Buildings that stand on soft soil usually use a pile foundation. Testing the ultimate bearing capacity of pile foundations in the field is a Pile Driving Analyzer (PDA) tool. Besides being inexpensive to test, the results can also be known quickly. This tool is supported by a software called CAPWAP (CAse Pile Wave Analysis Program).In this paper, a performance comparison of the Pile Driving Analyzer (PDA) and CAPWAP (CAse Pile Wave Analysis Program) software will be presented in producing the ultimate bearing capacity of pile foundations. The results of both will be analyzed in such a way that the causes of the differences in the performance of the Pile Driving Analyzer (PDA) and the CAPWAP software are known.The results obtained show that the performance of the Pile Driving Analyzer (PDA) tool will not be optimal if the energy transferred to the pile foundation is too small. The energy given by the hammer when struck must be in the range of 1% - 2%, if it is smaller then the performance of the tool in producing the ultimate bearing capacity will not be representative. The difference in the ultimate bearing capacity between the PDA device and the CAPWAP software for energy transferred to the pile foundation (EMX) under the specified energy standard is 10.71% - 33.23%. Meanwhile, energy that meets the specified standards has a value between 0.24% - 1.80%.

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