scholarly journals Effect of Loading Direction and Slope on Laterally Loaded Pile in Sloping Ground

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Chong Jiang ◽  
Jia-Li He ◽  
Lin Liu ◽  
Bo-Wen Sun

A series of three-dimensional finite element analyses were performed to study the behavior of piles in sloping ground under undrained lateral loading conditions. The analyses have been conducted for slopes with different angles and two loading directions. The obtained results show that as the slope increases, it can cause greater lateral displacement and internal force of the pile. In addition, the increase of the slope ratio will cause the position of the maximum bending moment and soil resistance zero point of the pile to move downward, further increasing the pile deflection. Furthermore, when the pile distance from slope crest B < 7D, the displacement and internal force development of the pile under toward loading is more obvious. When the pile distance from the slope crest exceeds 7D, the effect of loading direction on the pile can be neglected.

2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.


Author(s):  
Tomohiro Takaki ◽  
Toshimichi Fukuoka

The most important factor for the leakage problem of pipe flange connections is considered to be contact pressure distribution at the gasket bearing surface in service. In this study, the mechanical behaviors of the pipe flange connection are evaluated using FEM as a three-dimensional contact problem, in which a gasket is modeled as a nonlinear one-dimensional gasket element. Here, the contact pressure distributions at the gasket bearing surface and the variations of the bolt stress are estimated under uniform bolt preloads or nonuniform ones due to the elastic interaction during bolting up. The numerical procedure proposed here can successively deal with the processes of bolt-up, applying inner pressure and applying bending moment. The analytical objects are pipe flanges specified in JIS B 2238 with compressed asbestos sheet gaskets being inserted. The validity of the numerical method is ascertained by experiment.


2021 ◽  
Vol 318 ◽  
pp. 01010
Author(s):  
Mais S. Al-Tememy ◽  
Mohammed A. Al-Neami ◽  
Mohammed F. Asswad

Batter or raker piles are piles driven at an inclination with a vertical to resist large inclined or lateral forces. Many structures like offshore structures and towers are subjected to overturning moments due to wave pressure, wind load, and ship impacts. Therefore in such structures, a combination of the vertical and batter piles is used to transfer overturning moments in compression and tension forces to the foundation. This paper presents a three-dimensional finite element analysis using PLAXIS 3D software to study the battered pile's behavior under the effect of pullout load. Several variables that influence the pile tension capacity embedded in sandy soil are investigated. The pile models are steel piles embedded in the dense sand at different batter angles (0, 10, 20, and 30) degrees with two embedment ratios, L/d (15 and 20). To clarify the pile shape's influence on a pullout capacity, two shapes are used, a circular pile with a diameter equal to 20 mm and a square pile with a section of 15.7×15.7 mm. These dimensions are chosen to achieve an equal perimeter for both shapes. The numerical results pointed that the pile pullout capacity increases with the increasing of the batter angle and embedment ratio, and the maximum values are marked at a batter angle of 20o. The shape of the bending moment profile is a single curvature, and the peak values are located approximately at the midpoint of the battered pile, while a zero value is located at the pile tip and pile head.


Author(s):  
Koichi Okayama ◽  
Toshimichi Fukuoka

A reamer bolt is commonly used when clamping a rigid shaft coupling subjected to large shear force. Although some joint design procedures assume that the applied shear force transmits only through the reamer surface, it is also supported by the friction force on the contact surfaces. Accordingly, to design the coupling clamped by reamer bolts, it is important to evaluate the ratio of the shear forces supported by the reamer surface and the friction force, which is defined as shear force transfer ratio (SFTR) here. In this study, distributions of SFTR and the bending stresses along the reamer surface are analyzed by three-dimensional FEM, focusing on the effects of the fit between the reamer bolt and bolt hole, the scatter of initial bolt stress and the misalignment of the connecting shafts. Numerical results quantitatively clarify how the amounts of the SFTR and the bending stresses as the friction coefficients, the fit and the magnitude of misalignment are changed. As for an offset misalignment, it is found that its effect on the bending moment generated in the shaft body is negligibly small, if the offset between two shafts in radial direction is less than 10mm which is 1% of the total shaft length.


Author(s):  
Nghiem Xuan Hien

A hybrid analytical-numerical solution is proposed to solve the problem of a laterally loaded pile with a circular cross-section in multilayered soils. In the pile-soil model, the lateral load is located at the pile head including both lateral force and bending moment. The single pile is considered as a beam on elastic foundation while shear beams model the soil column below the pile toe. The differential equations governing pile deflections are derived based on the energy principles and variational approaches. The differential equations are solved iteratively by using the finite element method that provides results of pile deflection, rotation angle, shear force, and bending moment along the pile and equivalent stiffness of the pile-soil system. The modulus reduction equation is also developed to match the proposed results well to the three-dimensional finite element analyses. Several examples are conducted to validate the proposed method by comparing the analysis results with those of existing analytical solutions, the three-dimensional finite element solutions. Keywords: beam on elastic foundation; finite element method; pile; energy principle; lateral load.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Hao Zhang ◽  
Kai Sun

<p><strong> </strong>In this paper, in order to investigate the behavior of existing piles caused by the horizontal and compression deformation of soft substratum due to backfill surcharge on coastal floodplain, three-dimensional finite element models of piles adjacent to surcharge load were established. The deformation and migration law of soft soil was analyzed. The behavior of single pile and double row pile adjacent to surcharge load were studied, in which the influence of surcharge load location, surcharge pressure, pile stiffness, and pile top constraint conditions were considered. The results show that as the position of surcharge load is closer and the surcharge pressure increases, the response (e.g. deformation and bending moment) is more obvious. With the increase of pile stiffness, the range of passive load is increased. The deformation behavior of pile body under different constraints of pile cap is significantly different. The effect of secondary bending moment caused by pile axial force is obvious and cannot be ignored. If there is a thick soft substratum, it is beneficial to improve the behavior of adjacent piles by using cement mixing pile reinforcement.</p>


2012 ◽  
Vol 546-547 ◽  
pp. 89-96
Author(s):  
Jin Wei ◽  
Zhong Ju Feng ◽  
Feng Ma

In this paper, the geology characteristics of loess gulch area were summarized. The mechanical models of the influence of landslide, debris flow and soil erosion on the safety of the pile foundation were created. The influence of the geology casualty on the safety of the pile foundation were analyzed. The analyses showed, when the pile foundation located the varied position of the loess gulch, the influence of soil erosion on the pile foundation character (acting force of pile side, free length of the pile, the first zero point position of the flexure curve, drawdown of the maximum bending moment, the increment of the lateral displacement, the drawdown of the lateral bearing capacity, the drawdown of the stability, etc.) were strikingly different. The calculation method of the pile and pier internal force was put forward under the function of landslide thrust and pressing force of debris flow. The corresponding prevention measures to different influencing factors were presented in the end.


2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Aida Achour ◽  
Abdulmohsen Albedah ◽  
Faycal Benyahia ◽  
Bel Abbes Bachir Bouiadjra ◽  
Djamel Ouinas

Composite materials have been used to structurally repair piping and other facilities for many years. However, the original use of composite materials was for repairing corroded pipelines where the intent was to restore strength to the damaged section of the pipeline. In addition to repairing corrosion, composite materials have successfully been used to repair dents, wrinkle bends, induction bends, and pipe fittings including elbows and tees as well as repair of offshore risers. In this study, the behavior of circumferential through cracks in repaired pipe with bonded composite wrap subjected to bending moment is investigated using three-dimensional finite-element analysis. The stress intensity factor (SIF) is utilized as a fracture criterion. The effects of the mechanical and geometrical properties of the adhesive on the variation of the SIF at the crack front were also analyzed. The obtained results show that the presence of the bonded composite repair significantly reduces the SIF, which can improve the residual lifespan of the pipe. Meanwhile, the SIF is also reduced as the elastic and the geometrical wrap properties are improved, particularly when the Young's modulus of the adhesive and the wrap thickness are increased.


2014 ◽  
Vol 1065-1069 ◽  
pp. 613-618
Author(s):  
Zhi Hui Liu ◽  
Liang De He ◽  
Ying Fa He ◽  
Yuan Yuan Lu

In this paper, high-piled wharf is reinforced with a view to studying how the wharf dredging renovation affects its structure. As regarding the problem that the original balance of the bank slope is destroyed after upgrading, two retrofit schemes that set sheet pile wall at anterior wharf and low-piled caps at surcharge area are conducted to analyze the bank slope deformation and the inter force before and after wharf retrofit by means of three-dimensional finite element models. The analysis shows that for the scheme of setting sheet pile wall at front wharf, the inter force of the anterior pile station reduced while that of the post pile station near the stack area remains large. For the other scheme, the bending moment of the pile that closes to stack area significantly decreases after setting low pile caps. If both schemes are adopted coherently, the reinforcement effects to the anterior and post pile stations would be improved greatly.


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