scholarly journals Theoretical and Actual Bearing Capacity of Driven Piles Using Model Piles in Sand

2015 ◽  
Vol 773-774 ◽  
pp. 1453-1459
Author(s):  
Wong Kok Leong ◽  
Nor Azizi Yusoff ◽  
Ameer Nazrin Abd Aziz ◽  
Zaihasra Abu Talib

In general, increasing of penetration rate may result in an increased of pile capacity. Occasionally, there were differences between theoretical and actual bearing capacity of the piles. Rate of penetration of pile influenced the pile bearing capacity. The bearing capacity of model pile increased as the rate of loading increased based on pile driving formula. Therefore, the study was conducted to determine the bearing capacity of model piles with different penetration forces based on theoretical method and experimented analysis. Five circular hollow section model piles using pipe pile were used to penetrate into cohesionless soil with different penetration force respectively. The loading for ultimate bearing capacity using theoretical calculation was approximately about 0.163kN.However, referring to the limitation of a laboratory setup, the maximum loading was 0.12kN. Several trials had been initiated but when it reached 0.14kN, the setup was unstable and dangerous to be continued. Therefore, the ultimate bearing capacity derived by the pile load test results were based on a pile moved up to 10% of its tip diameter criteria. In the future, both theoretical and actual calculation must be made to avoid any confusion and detect mistakes in near future.

2011 ◽  
Vol 368-373 ◽  
pp. 473-477
Author(s):  
Xing Ping Shu ◽  
Zhi Shen Yuan ◽  
Zheng Rong Zhu ◽  
Yao Yao

This paper presents the experimental and numerical results of the ultimate bearing capacity of partially overlapped tubular N-joints, which have circular hollow section (CHS) brace members welded to a square hollow section (SHS) chord member. Two partially overlapped N-joints were tested to failure under overlapping brace axial loading and chord axial loading. The failure mode of specimen N1 was the overlapping brace local bucking, and the failure mode of specimen N2 was the chord face plastification with chord side wall buckling. Meanwhile, weld fracture occurred on both specimens. Then, making use of finite element package program ANSYS, in which twenty nodes solid element was employed and the weld was simulated, elastic-plastic large deflection finite element analysis of the experimental joints was conducted. The experimental data were compared with the results acquired by finite element analysis and it was proved that ANSYS is feasible to simulate the connecting weld and analyze the static behavior of partially overlapped CHS-to-SHS welded N-joints.


2011 ◽  
Vol 250-253 ◽  
pp. 2271-2275
Author(s):  
Cheng Wang ◽  
Qi Zhang

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.


This paper discusses the Ultimate Bearing Capacity of a stabilized soil by using the fly ash, stone dust and rubber powder for design of a pavement. This paper will help in utilization of locally available waste materials to reuse in the subbase and subgrade layers of pavement. Rubber powder is a waste byproduct generated from the recycling of tires, and is not so easy for degradable, and hence leads to release of harmful gases when it tends to burn. Stone dust is a locally available waste generated product from quarries. The generation of stone dust is increasing day to day in large quantity. The huge quantity of stone dust storage amount will affect the quality of soil. Fly ash is waste combusted coal ash powder generated from the steamers of coal boilers with the burning of fuel gases together. In the sub grade layer the soil is mixed in different proportions with stone dust for hard foundation. In the sub base layer the soil is stabilized with the combination of rubber powder and fly ash. When the rubber powder and fly ash, mixed with water for compaction generates a bond between the soil particles to settle the air fields. In this paper various percentages of rubber powder, stone dust and fly ash with different samples for pavement is layered, and after that plate load test is conducted upon it.


2013 ◽  
Vol 341-342 ◽  
pp. 1449-1452
Author(s):  
Qing Dun Zeng ◽  
Fang Liu

Various new type scaffolds have been introduced and developed in China. They are novel in structure and economic in material, but their security and reliability can not be ignored. This paper introduced a new chained formwork support frame with nine upright tubes and many cross-braced connections. Firstly, the load test of the support frame was performed in order to observe the failure process and to determine the ultimate bearing capacity. Then, the strength and stability of both single upright tube and a cross-braced rod were checked according to the existing specifications on scaffolds. Finally, a finite element software ANSYS was used to establish a solid model for the support frame. The structural stability was analyzed and the ultimate bearing capacity was calculated. The comparison between the computational and experiment results was carried out. The results show that the ultimate bearing capacity of the new chained formwork support frame is controlled by the structural stability.


2021 ◽  
Vol 13 (23) ◽  
pp. 13166
Author(s):  
Xusen Li ◽  
Jiaqiang Zhang ◽  
Hao Xu ◽  
Zhenwu Shi ◽  
Qingfei Gao

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.


2012 ◽  
Vol 594-597 ◽  
pp. 565-569
Author(s):  
Zi Sen Wei ◽  
Yong Mou Zhang ◽  
Dong Hui Peng

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.


2012 ◽  
Vol 256-259 ◽  
pp. 531-534
Author(s):  
Jia Tao Wang ◽  
Hong Li Zhao

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.


2014 ◽  
Vol 638-640 ◽  
pp. 365-369
Author(s):  
Shu Jun Zhang ◽  
Zhi Jun Xu ◽  
Kai Wang ◽  
Bo Zhang

This paper aims to study the distribution characteristics of the ratio of measured value and calculated value for ultimate bearing capacity, shaft resistance and tip resistance, and discuss the impact of shaft resistance and tip resistance on ultimate bearing capacity. A new performance function is proposed in terms of the three types of bearing capacity mentioned ahead. Take bored piles and driven piles for example, and the results from analysis indicate that the ratio of the measured value to calculated value of bored piles ranges from 0.75 to 1.45, and mostly is greater than 1.0; The ratio of the measured to predicted bearing capacity of driven piles lies between 0.8 and 1.5, and is larger than the corresponding ratio of bored piles. In addition, the reliability of tip resistance is lager than that of shaft resistance for bored pile, while the reliability of tip resistance is less than that of shaft resistance for driven piles. Meanwhile, the method presented in this paper can offer references to designers for revising and improving the technical code for pile foundations.


Sign in / Sign up

Export Citation Format

Share Document