“…9 a, the damage pattern appeared in this study can be identified as the second damage pattern mentioned above, which was caused by the increase of friction due to the pile was frictional. And the failure pattern of this test was consistent with previous study 22 . Figure 10 Relationship between Ultimate bearing capacity and length-diameter ratio.…”
Section: Lab Testssupporting
confidence: 91%
“…The single pile studied in this paper corresponds to the pile used in the tunnel section of the Heyi River Crossing Project in Quzhou City, Zhejiang Province, China. The pile length used in the project is 10 m and the pile diameter is 1 m. To simulate the in-situ pile in the model box and eliminate the scale effect 19 – 22 , a reduction factor of n = 30 was applied for the reduced scale test. The test device is made up of three parts: the model box, the loading system, and the image acquisition device.…”
The uplift pile is an anti-uplift measure in engineering widely used in practice. In order to study the mechanical parameters of the pile and the surrounding soil under the uplift load, a pile uplift model test and relevant numerical test were conducted. Image analysis technique was applied to the model test to investigate the soil displacements caused by pulling the pile. The load–displacement and pile axial force-lateral friction resistance relationships were investigated at three burial depths. Comparing the model test and numerical test results, it reveals that the pile primarily underwent four stages under the influence of uplift load: initial stage of loading, strain-hardening stage, peak of loading stage, and the strain-softening stage; the soil displacements around the pile exhibited inverted conical shape as the uplift load increases; and obvious soil arching effects could be observed near the ground surface. In addition, the development of force chains and major principal stresses indicated that the pile lateral frictional resistance first increased to its maximum value and then decreased sharply along the depth direction.
“…9 a, the damage pattern appeared in this study can be identified as the second damage pattern mentioned above, which was caused by the increase of friction due to the pile was frictional. And the failure pattern of this test was consistent with previous study 22 . Figure 10 Relationship between Ultimate bearing capacity and length-diameter ratio.…”
Section: Lab Testssupporting
confidence: 91%
“…The single pile studied in this paper corresponds to the pile used in the tunnel section of the Heyi River Crossing Project in Quzhou City, Zhejiang Province, China. The pile length used in the project is 10 m and the pile diameter is 1 m. To simulate the in-situ pile in the model box and eliminate the scale effect 19 – 22 , a reduction factor of n = 30 was applied for the reduced scale test. The test device is made up of three parts: the model box, the loading system, and the image acquisition device.…”
The uplift pile is an anti-uplift measure in engineering widely used in practice. In order to study the mechanical parameters of the pile and the surrounding soil under the uplift load, a pile uplift model test and relevant numerical test were conducted. Image analysis technique was applied to the model test to investigate the soil displacements caused by pulling the pile. The load–displacement and pile axial force-lateral friction resistance relationships were investigated at three burial depths. Comparing the model test and numerical test results, it reveals that the pile primarily underwent four stages under the influence of uplift load: initial stage of loading, strain-hardening stage, peak of loading stage, and the strain-softening stage; the soil displacements around the pile exhibited inverted conical shape as the uplift load increases; and obvious soil arching effects could be observed near the ground surface. In addition, the development of force chains and major principal stresses indicated that the pile lateral frictional resistance first increased to its maximum value and then decreased sharply along the depth direction.
“…Belled pile is a typical expanded pile to be used in engineering practice. The failure mechanism behind uplift belled piles in the level ground is sufficiently studied (Sawwaf and Nazir, 2006;Hong and Chim, 2015;Schafer and Madabhushi, 2020;Abdelgwad et al, 2022). Moreover, many scholars have studied various influential factors on the uplift capacity of belled piles in the level ground, for example, sand density (Ilamparuthi and Dickin, 2001;HondaHirai and Sato, 2011), diameter of the expanded base, embedment depth of piles (Tanaya and Sujit, 2019;Kang and Kang, 2022), and different bell space ratios (Sun et al, 2022).…”
Single piles are normally used to support the transmission tower in mountain areas. Uplift capacity of piles is a key factor in the engineering design to increase the stability of transmission tower foundation. This study numerically investigated the uplift capacity of single straight and belled piles in the sloping ground which consisted of a clay layer underlain by medium weathered sandstone. A non-linear 3D finite element model was proposed to describe the uplift behavior of single piles and was calibrated against a field test on single piles subjected to uplift loading. A parametric study was conducted to investigate the effect of the slope angle (θ) on the uplift behavior of single piles. The uplift capacity decreased as θ increased for either straight piles or belled piles. Moreover, the range of the equivalent plastic strain was greatest for single piles in the level ground. For piles in the sloping ground, the range of equivalent plastic strain was wider at the position of the downstream slope than that at the position of the upstream slope when the uplift load of single piles reached the maximum. As the expansion angle increased to 30° and 45°, the uplift capacity of belled piles (Ru) was increased by 100% and 180% with respect to that of straight piles, respectively. The increase percentage in Ru was independent of θ. A practical method was proposed to quantify the slope effect on Ru.
“…Sakr et al 10 tried to use an anchor wing to improve the uplift capacity of a pile and found that this method is effective. Abdelgwad et al 11 conducted thirty-nine tests of enlarged base piles and normal piles to investigate the effect of enlarged bases. Based on the normal uplift pile, the bottom uplift pile has been invited, and an increasing number of researchers have tried to determine its bearing mechanism.…”
The bottom uplift pile, which has been applied in practical projects, has the following advantages: the pile body is not easy to crack, good bearing characteristics, and small displacement of the pile top. Based on the bearing capacity test of foundation piles in the third stage expansion project of Lanzhou Zhongchuan International Airport, the upper part pile of the self-balancing test method was used to simulate the bottom uplift pile, and the anchor piles in the anchor pile method were regarded as normal uplift piles. The bearing characteristics of the bottom uplift pile in a layered foundation were studied by comparing these two kinds of piles. The results show that under the same displacement of the pile top, the ultimate uplift bearing capacity of the bottom uplift pile can be more than twice that of the normal uplift pile because of the fully exerted frictional resistance of the soil at the bottom of the pile, the Poisson effect of the pile body and the avoidance of the influence of pile body deformation on the pile top displacement. The maximum axial force of the bottom uplift pile appears at the bottom of the pile and gradually decreases from the bottom to the top, which is opposite to that of the normal uplift pile. The properties and thickness of the soil layers around the pile have a great influence on the distribution curves of the frictional resistance along the pile length of the two kinds of uplift piles. With changing soil layer conditions, the distribution curve may be a "parabola", a "straight line" or a "double line". The soil property plays a decisive role in the frictional resistance, which may cause softening. The influence of the pile diameter on the ultimate uplift bearing capacity is greater than that of the pile length, while the elastic modulus of the pile has little influence.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
