Study on Vertical Bearing Capacity and Time Effect of the Jacked-in PHC Pipe Pile in the Cohesive Soil Area

2011 ◽  
Vol 368-373 ◽  
pp. 2706-2710
Author(s):  
Hong Liang Zuo ◽  
Lei Wang ◽  
Hong Ying Gao ◽  
Liang Guo
Keyword(s):  
Bearing Capacity ◽  
Cohesive Soil ◽  
Ultimate Bearing Capacity ◽  
Time Effect ◽  
Load Test ◽  
Static Load Test ◽  
Empirical Coefficient ◽  
Pipe Pile ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

The static load test of 34 jacked-in PHC pipe piles of medium length are performed in the cohesive soil area, the relationship between the vertical ultimate bearing capacity and the final pressure, and the time effect of vertical bearing capacity of the jacked-in PHC pipe pile are studied. The data of static load test is analyzed statistically with software SPSS, the regional empirical coefficient about the vertical ultimate bearing capacity and final pressure, and the time effect formula about vertical bearing capacity of the jacked-in PHC pipe pile in the cohesive area are obtained. According to the regional empirical coefficient, the pile pressing machine and counterweight can be chosen reasonably and the vertical ultimate bearing capacity of single pile can also be estimated rapidly, then we can instruct the design and construction of the jacked-in PHC pipe pile. According to the time effect formula, the vertical bearing capacity at different periods of the jacked-in PHC pipe pile can be obtained, the cost of the foundation engineering can be reduced by considering the time effect influence to the vertical bearing capacity of the jacked-in PHC pipe pile.

Reliability Analysis of the Vertical Bearing Capacity of Prestressed Pipe Pile Foundations

2013 ◽  
Vol 671-674 ◽  
pp. 90-93
Author(s):  
Chun Yuan Liu ◽  
Meng Xuan Zhao ◽  
Yu Liu
Keyword(s):  
Bearing Capacity ◽  
Theory Model ◽  
Load Test ◽  
Pile Foundations ◽  
Static Load Test ◽  
Pipe Pile ◽  
Software Analysis ◽  
Finite Element Software ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

The paper introduces the basic principles of vertical bearing capacity of the pile by using static load test, establish the random site theory model of the bearing capacity of prestressed pipe pile foundations calculation, calculates and statistics the try count ratio of vertical bearing capacity of 144 prestressed pipe pile in Tianjin, work out calculation procedures of JC method, calculate reliability index of vertical bearing capacity and analyze calculation results. In the last, we build a model using the finite element software, analysis the displacement of pile top under earthquake, evaluates the horizontal bearing capacity of prestressed pipe pile.

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.

scholarly journals A Novel Numerical Method for Calculating Vertical Bearing Capacity of Prestressed Pipe Piles

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Rongbao Chen ◽  
Jichao Zhang ◽  
Zeyu Chen ◽  
Meixiang Gu
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Hard Rock ◽  
Soft Rock ◽  
Load Test ◽  
Static Load Test ◽  
Soil Layers ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity ◽  
Rock And Soil

A novel method for calculating the vertical bearing capacity of prestressed pipe piles with the acceptable error was proposed and verified. Soils at the pile side and end were, respectively, simulated by an elastic-plastic model and a new double-line (at soft rock and soil layers) or triple-line model (at hard rock and soil layers); then, a mechanical model was established for simulating vertical bearing capacity of prestressed pipe piles, and the corresponding calculation process was carried out. The values of pile side resistance, pile end resistance, and pile end elastic displacement were first obtained from the results of high-strain dynamic testing (HSDT) and then were imported into the proposed numerical model for calculating the vertical bearing capacity of prestressed concrete pipe piles. The static load test was carried out to verify the numerical results. Besides, 20 piles were tested at two typical test sites (soft and hard rock bearing strata), of which 8 piles were arranged at the soft rock bearing stratum site and 12 piles were arranged at the hard rock bearing stratum site. The numerical results achieved from an empirical formula were also used for making a comparison. The values obtained by the proposed method were highly close to those achieved from the static load test with an error of within 10%. The outcomes indicated that the proposed numerical method can be potentially applied to predict the bearing capacity of prestressed pipe piles.

Vertical Bearing Capacity Properties Study of Punched Cast-in-Place Pile Based on Field Test in Driving Analysis Test on Piles of a Thermal Power Plant

2012 ◽  
Vol 594-597 ◽  
pp. 691-696
Author(s):  
Lei He ◽  
Shi Jun Ding ◽  
Zi Xia Feng ◽  
Zhi Wei Han
Keyword(s):  
Bearing Capacity ◽  
Thermal Power ◽  
Internal Force ◽  
Load Test ◽  
Static Load Test ◽  
Large Area ◽  
Tip Resistance ◽  
Geological Conditions ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

Through the vertical static load test of pile, studied and demonstrated the applicability of cast-in-place piles in the construction of a thermal power plant’s in Guangxi Zhuang Autonomous Region, china. By testing the internal force of pile shaft, obtained the distribution of axial force, side friction and tip resistance, and ascertained the vertical bearing capacity of punched cast-in-place piles in the engineering geological conditions of this project. This research provides the important quality control standards and design basis for the follow-up pile foundation construction of large area of this project, and also provides reference for other projects in this area.

Prediction of Vertical Ultimate Bearing Capacity in Piles Based on the Improved Hyperbolic Model

2011 ◽  
Vol 250-253 ◽  
pp. 2271-2275
Author(s):  
Cheng Wang ◽  
Qi Zhang
Keyword(s):  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Load Test ◽  
Hyperbolic Model ◽  
Maximum Point ◽  
Static Load Test ◽  
Hyperbolic Curve ◽  
The Mathematical Model ◽  
Test Pile

Vertical static load test is widely used in the determination of pile bearing capacity, the mathematical model used to fit test pile data in determining the bearing capacity is essential. From the perspective of analytic geometry, the paper analyzes the traditional method of hyperbola, of which the asymptotic line of equilateral hyperbola was used to determine the ultimate bearing capacity. By extending the equal-axed conditions, a more general form of hyperbolic equation is derived and feasibility of such method is also analyzed, which indicates that the maximum point of curvature in such hyperbolic curve can determine the ultimate bearing capacity and such method is proved to be reasonable in practical projects.

Numerical Analysis on the Bearing Capacity of Single Pile in Deep Excavation Area

2013 ◽  
Vol 671-674 ◽  
pp. 226-229
Author(s):  
Jun Jie Wu ◽  
Jin Jian Chen ◽  
Shuai Jun Liu ◽  
Jian Hua Wang
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Numerical Study ◽  
Back Analysis ◽  
Load Test ◽  
Deep Excavation ◽  
Static Load Test ◽  
Fem Modeling ◽  
Vertical Bearing ◽  
Element Technique

Large-scale deep excavation may affect the bearing capacity of piles inside the excavation zone. It does not only cause the loss of friction, but also change the stress state of the subsoil. In this paper, nonlinear finite element technique is employed to investigate the bearing capacity of piles influenced by the deep excavation. Parameters of soil are obtained by back analysis on the pile static load test results. The bearing capacity of the piles during excavation is analyzed by performing FEM modeling under three conditions using the calibrated parameters. The numerical study shows that the loss ratio of vertical bearing capacity of pile foundation caused by excavation unloading is 34%.

Testing Study on Bearing Behavior of Belled Large-Diameter PHC Pipe Pile by NAKS (Nakabori Kakutei System) Construction Method

2013 ◽  
Vol 353-356 ◽  
pp. 533-539 ◽  
Author(s):  
Wen Xu ◽  
Yu Bin Hou
Keyword(s):  
Bearing Capacity ◽  
Large Diameter ◽  
Field Testing ◽  
Construction Method ◽  
Load Test ◽  
Test Field ◽  
Static Load Test ◽  
Pipe Pile ◽  
Bored Pile ◽  
Bearing Behavior

Through field static load test and pile shaft axial force test, field testing study is conducted on bearing behavior of NAKS-construction-method belled large-diameter PHC pipe pile; besides, the test result is compared with that of hammering-method PHC pipe pile and bored pile with same pile length and diameter under the same site condition. The result shows that the ultimate bearing capacity of NAKS-construction-method belled large-diameter PHC pipe pile is slightly inferior to hammering-method PHC pipe pile but obviously superior to that of bored pile. Compared with traditional hammering-method pipe pile, the pile side resistance of NAKS-construction-method belled pipe pile is smaller; however, the higher toe resistance will give better play to bearing capacity of bearing stratum of pile toe; moreover, it is found that under the action of ultimate load and failure load, the maximum settlement and final settlement of NAKS-construction-method belled pipe pile tip are obviously lower than that of other test piles, which is conductive to lessening foundation settlement of upper structure.

scholarly journals Static Load Test and Numerical Analysis of Influencing Factors of the Ultimate Bearing Capacity of PHC Pipe Piles in Multilayer Soil

2021 ◽  
Vol 13 (23) ◽  
pp. 13166
Author(s):  
Xusen Li ◽  
Jiaqiang Zhang ◽  
Hao Xu ◽  
Zhenwu Shi ◽  
Qingfei Gao
Keyword(s):  
Numerical Analysis ◽  
Bearing Capacity ◽  
Influencing Factors ◽  
Static Load ◽  
Young Modulus ◽  
Ultimate Bearing Capacity ◽  
Load Test ◽  
Freezing Stress ◽  
Static Load Test ◽  
Tip Resistance

Prestressed high-strength concrete (PHC) pipe piles have been widely used in engineering fields in recent years; however, the influencing factors of their ultimate bearing capacity (UBC) in multilayer soil need to be further studied. In this paper, a static load test (SLT) and numerical analysis are performed to obtain the load transfer and key UBC factors of pipe piles. The results show that the UBC of the test pile is mainly provided by the pile shaft resistance (PSR), but the pile tip resistance (PTR) cannot be ignored. Many factors can change the UBC of pipe piles, but their effects are different. The UBC of the pipe pile is linearly related to the friction coefficient and the outer-to-inner diameter ratio. Changes in the pile length make the UBC increase sharply. Low temperatures can produce freezing stress at the pile–soil interface. The effect of changing the Young modulus of pile tip soil is relatively small.

Finite Element Analysis of Cushion Thickness and Ultimate Bearing Capacity of Lime Soil Pile Composite Foundation

2012 ◽  
Vol 594-597 ◽  
pp. 565-569
Author(s):  
Zi Sen Wei ◽  
Yong Mou Zhang ◽  
Dong Hui Peng
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Stress Ratio ◽  
Shear Failure ◽  
Ultimate Bearing Capacity ◽  
Load Test ◽  
Composite Foundation ◽  
Static Load Test ◽  
Rate Of Increase ◽  
Soil Stress

The static load test of composite foundation was simulated by using the nonlinear finite element programs, and the changes of the pile-soil stress ratio and the pile and soil settlements as well as the plastic deformation of composite foundation were analyzed. The simulation results show that: the cushion of flexible pile composite foundation can effectively regulate the pile-soil stress ratio and make the bearing capacity of the lime soil pile and the soil between piles give full play at the same time. The cushion has a distinct role in reducing the pile settlements, however, has little effect in reducing the soil settlements. The reasonable cushion thickness is about 300mm. The composite foundation will emerge local shear failure when it reaches the ultimate bearing capacity. Reducing the pile spacing can increase the ultimate bearing capacity, and the rate of increase shows a gradually increasing trend.

scholarly journals Predicting the bearing capacity of pile installed into cohesive soil concerning the spatial variability of SPT data (A case study)

2021 ◽  
Vol 11 (1) ◽  
pp. 45-64
Author(s):  
Duong Hong Tham ◽  
Truong Nhu Manh
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Physical And Mechanical Properties ◽  
Cohesive Soil ◽  
Load Test ◽  
Penetration Test ◽  
Static Load Test ◽  
In Situ Tests ◽  
Spt Data

Nowadays, in situ tests have played a viable role in geotechnical engineering and construction technology. Besides lab tests conducted on undisturbed soil samples, many different kinds of in-situ tests were used and proved to be more efficient in foundation design such as pressuremeter PMT, cone penetration test CPT, standard SPT, etc. Among them, a standard penetration test (SPT for short) is easy to carry out at the site. For decades, it has proved reliable to sandy soil, but many viewpoints and opinions argued that the test was not appropriately applicable to cohesive soil because of scattered and dispersed data of SPT blow counts through different layers. This paper firstly studies how reliable the SPT data can predict the physical and mechanical properties; secondly, the soil strength is determined in terms of corrected N-SPT values, and finally the bearing capacity of a pile penetrating cohesion soil. By analyzing data from 40 boreholes located in 18 projects in Ho Chi Minh City, South VietNam, coefficients of determination between SPT numbers and physical and mechanical properties of different soil kinds are not the same: R2 = 0.623 for sand, =0.363 for sandy clay and =0.189 for clay. The spatial variability of soil properties is taken into account by calculating the scale of fluctuation θ=4.65m beside the statistically-based data in horizontal directions. Finally, the results from two theoretical approaches of predicting pile bearing capacity were compared to those of finite element program Plaxis 3D and static load test at site. Correlation between the capacity computed by using corrected N-values instead of soil strength and results of static load test has proved to be well suitable in evaluating the bearing capacity of driven and jack-in piles, particularly installing in the cohesive soil using the SPT blows.

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