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

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.

2016 ◽  
Vol 35 (5) ◽  
pp. 738-745 ◽  
Author(s):  
Zhaoyu Wang ◽  
Nan Zhang ◽  
Guojun Cai ◽  
Qi Li ◽  
Jiajia Wang

2013 ◽  
Vol 838-841 ◽  
pp. 935-939
Author(s):  
Xin Quan Wang ◽  
Xin Jiang Wei ◽  
An Yuan Liu ◽  
Juan Liao ◽  
Lian Wei Ren

The side friction of Y-section pile is non-uniform distributed along its inverted arch arc, the load - settlement law of Y-section pile distinguishes to the traditional piles' as there is abnormality effect of side friction. Computation theory of settlement and ultimate bearing capacity needs to be studied. Calculate the settlement under different loads based on the model of skin friction, ultimate tip resistance and additional stress coefficient, and then predict ultimate bearing capacity by loads-settlement laws, the theoretical values of settlement and ultimate bearing capacity are in good agreement with the results of Static load test. The influences of five variables R, θ, δ, s, and L on settlement of Y-section file are analyzed, the settlement of Y-section pile under the constant load decreases with the increase of R, δ, s, δ and increases with the increase of θ. The influences of Relevant parameters on ultimate bearing capacity are also analyzed, the ultimate bearing capacity of Y-section pile decreases with the increase of θ and increases with the increase of R, δ, s and L.


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.


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.


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>


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.


2014 ◽  
Vol 501-504 ◽  
pp. 150-154
Author(s):  
Dong Guo Li ◽  
Jian Ping Chen ◽  
Yong Qiang Zhang

The applicability of the plate body stabilization technology was determined basing on the different treatment methods on soft foundation in Caofeidian areas. It discussed the construction technology and the main points of construction furtherly on the plate body stabilization technology. The soft foundation bearing capacity reached 200kpa and the settlement amount was less than 16mm through static load test after dealing with the soft foundation. The results meet the specifications and project requirements.


2014 ◽  
Vol 638-640 ◽  
pp. 671-674
Author(s):  
Yu Zhou Sima ◽  
Qing Hua Sun

In static load test, most of piles do not destroy, the piles still exist capacity, which reduce the reliability index of pile foundation. This paper employs Bayesian Statistic method to update the measured capacity of piles. Meanwhile, based on updating data, the reliability index is calculated considering the destruction of piles. The case study shows that the reliability index of capacity becomes large when the time of pile destruction increases. Therefore, when judging the safety of pile foundation, it is highly necessary to consider the influence of pile destruction on reliability of piles.


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