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

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.

2012 ◽  
Vol 594-597 ◽  
pp. 691-696
Author(s):  
Lei He ◽  
Shi Jun Ding ◽  
Zi Xia Feng ◽  
Zhi Wei Han

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.


2013 ◽  
Vol 671-674 ◽  
pp. 90-93
Author(s):  
Chun Yuan Liu ◽  
Meng Xuan Zhao ◽  
Yu Liu

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.


2011 ◽  
Vol 368-373 ◽  
pp. 2706-2710
Author(s):  
Hong Liang Zuo ◽  
Lei Wang ◽  
Hong Ying Gao ◽  
Liang Guo

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.


2013 ◽  
Vol 671-674 ◽  
pp. 226-229
Author(s):  
Jun Jie Wu ◽  
Jin Jian Chen ◽  
Shuai Jun Liu ◽  
Jian Hua Wang

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%.


2015 ◽  
Vol 77 (11) ◽  
Author(s):  
Helmy Darjanto ◽  
Masyhur Irsyam ◽  
Sri Prabandiyani Retno

The Spider Net System Footing (SNSF) is a raft foundation system that commonly used in Indonesia. It contains a plate, downward ribs system for reinforcement, and the compacted filled soil. The ribs are in longitudinal and transversal, called as settlement rib and in diagonal direction, named as construction rib. This paper explores the load transfer mechanism along the plate, the ribs, filled soil and the base soil under the footing system. The mechanism is investigated by conducting full scale static load test on SNSF. Strain gauges were installed to monitor the strain increment of each footing elements during loading. 3D numerical analysis was also conducted to verify the experimental results. To analyze the results, Load-Ultimate Ratio Factor (L-URF) was proposed. L-URF was a ratio between ultimate soil bearing capacity of the SNSF and the applied loading at specific element. Higher the L-URF value means higher loading applied at its associate element. Both experimental and numerical results show that at the first stage the loading was fully carried out by the tip of the ribs and transferred to the soil stratum under the footing system. Increasing the loading, the ribs, plate, and filled soil altogether sustain the loading and then transferred to the soil stratum below the footing system. The results also affirm that SNSF generate higher bearing capacity compare with simple shallow footing.  


2013 ◽  
Vol 838-841 ◽  
pp. 854-857
Author(s):  
Rui Chao Cheng ◽  
Xin Yu

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.


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.


Author(s):  
Masaaki Isa ◽  
Masatsugu Shinohara ◽  
Yasumoto Aoki

<p>Collapse and falling of columnar structures such as road illumination poles installed on a bridge have been confirmed in the past earthquakes. Therefore, it is important to evaluate the seismic resistance of columnar structures from the viewpoint of securing the function as an emergency transportation route in the event of disaster. In this study, the destruction order and destruction form of the road illumination pole in the external force action were analyzed and verified, and the model specimen was produced to carry out the static load test. As a result of the experiment, it was shown that anchor bolts and wall concretes of the base were damaged antecedently.</p>


2014 ◽  
Vol 501-504 ◽  
pp. 269-274
Author(s):  
Yang Chen ◽  
Zhi Hong Huang

In recent decades,there have been detailed investigations of bearing capacity of muddy dolostone through in-suit static load and uniaxial compressive strength.By analyzing test datas,the vertical bearing capacity, uniaxial compression and water ratio were studied.The bearing capacity which will be performed on slight , medium、strong weathering ,muddy dolostone.By the fact that the single axis compression strength and the water ratio experiment study to the slight weathering 、the medium weathering 、the strong weathering muddy dolostone, explain that making use of fitting equation to come to oppose guessing the bearing capacity of the foundation, is feasible,above all for medium and strong weathering muddy dolostone.


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