Theoretical Study on Influence of Disk Spacing on Soil Failure State of Expansion Piles under Horizontal Force

2020 ◽  
Vol 980 ◽  
pp. 301-310
Author(s):  
Yong Mei Qian ◽  
Ting Ting Zhou ◽  
Wei Tian ◽  
Phaaroe Pherekhong Alphonci
Keyword(s):  
Bearing Capacity ◽  
Design Theory ◽  
High Efficiency ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Horizontal Load ◽  
Construction Technology ◽  
Finite Element Software ◽  
Spacing Parameter ◽  
Disk Spacing

Concrete expansion pile represents a new type of high-efficiency and energy-saving variable-section filling pile and it is formed by special construction technology and equipment, this technology has been basically mature which has been gradually applied to engineering in recent years. It has high bearing capacity, small settlement and uniformity, good economic and social effect, strong anti-overturning ability and flexible design[1]. In this paper, with expansion disk spacing under bearing force as the main parameter variable, numerical simulation is carried out by ANSYS finite element software to analyze the variation relationship between horizontal displacement of the pile top, bending moment of the pile and soil stress around the pile of different disk spacing models under horizontal load, and determine the influence of disk spacing parameter on horizontal bearing capacity of the concrete expansion pile. Through the research of this paper, the influence of failure mode of concrete expansion pile and size of the disk spacing on the horizontal bearing capacity under the horizontal load is qualitatively determined, which provides a theoretical basis for improving design theory and practical application of concrete expansion pile.

Model Test Study on the Effect of Horizontal Load on the Vertical Bearing Capacity of Disk Pile

2011 ◽  
Vol 368-373 ◽  
pp. 2571-2574
Author(s):  
Cheng Yuan Lu ◽  
Jin Jin Li ◽  
Fan Li Meng
Keyword(s):  
Bearing Capacity ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Initial Time ◽  
Horizontal Load ◽  
Vertical Load ◽  
Soil Pressure ◽  
Test Study ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

A group of model tests were designed to study the effect of horizontal load on the vertical bearing capacity of disk pile. Three double-disk piles were used in the test, and the distance of the two disks is 5 times as the disk diameter. Drew a horizontal load H=100N/200N/300N on the top of pile1/2/3 respectively, and put on the vertical load stage by stage, then studied the differences of three piles’ bearing properties such as changes of the pile bending moment, the horizontal and vertical deformation on the top, and soil pressure around the pile. Experiment showed that when the horizontal load is quite small, the existence of horizontal load has little to do with vertical bearing capacity. When the load reached a certain level, the p-∆ effect under the vertical load will significantly affect the vertical bearing capacity of the pile. Especially during the initial time while there is a large horizontal displacement or rotation generated by the horizontal load, the pile’s bearing capacity is controlled by the horizontal displacement.

Model Test Study on the Effect of Vertical Lode on Horizontal Bearing Capacity of Disk Pile

2012 ◽  
Vol 446-449 ◽  
pp. 1804-1807
Author(s):  
Fan Li Meng ◽  
Guang Yu Sun ◽  
Cheng Yuan Lu
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Combined Loading ◽  
Horizontal Load ◽  
Vertical Deformation ◽  
Vertical Load ◽  
Disk Diameter ◽  
Test Study

In order to study how it influence the horizontal bearing capacity of the disk pile when there exists a vertical load, a group of model tests has been designed. Three double-disk piles were used in the test, and the distance of the two disks is 5 times as the disk diameter. First drew a vertical load V=200N/300N/400N on the top of pile1/2/3 respectively, then put on the horizontal load stage by stage. And by the test, we can study the differences of the pile bearing properties such as changes in the pile bending moment, the horizontal and vertical deformation on the top. Experiment showed that when the vertical load is quite small（V=200N、300N）, the existence of vertical load has little to do with horizontal bearing capacity. When a vertical load increases to a certain value（V=400N）, The maximum bending moment and horizontal displacement of the pile under the same horizontal load reduce, which indicates that the disks of the pile play a significant role in bearing combined loading.

scholarly journals Influence of Karst Caves at Pile Side on the Bearing Capacity of Super-Long Pile Foundation

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Peisen Wang ◽  
Hongyan Ding ◽  
Puyang Zhang
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Horizontal Load ◽  
Karst Cave ◽  
Karst Caves ◽  
Karst Areas ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

The differences in development and situation of karst caves lead to two kinds of karst caves, and the karst cave may be on the pile side or at the pile bottom, which has a different influence on the bearing capacity of pile foundation. The paper presents a numerical analysis of the influence of karst caves at pile side on the bearing capacity of super-long pile foundation in karst areas. According to the size of pile foundation of a real bridge project, this paper modelized karst caves and investigated the karst cave from the effect of length, height, and thickness of roof on horizontal and vertical bearing capacity of pile foundation. The main conclusions can be drawn as: when the horizontal displacement at the top of pile foundation is greater than 0.05 m, the horizontal load is correlated positively with the length of karst cave; when the vertical displacement is greater than 0.07 m, the vertical load is correlated negatively with the thickness of the roof of karst cave. However, the height of karst cave has little effect on the bearing capacity; also the existence of karst cave has little influence on the dynamic response of pile foundation. The results of this study can be important with reference to the design and construction of pile foundations in karst areas.

scholarly journals Failure and Remediation of an Embankment on Rigid Column-Improved Soft Soil: Case Study

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Shaofu Gu ◽  
Weizheng Liu ◽  
Mengyuan Ge
Keyword(s):  
Bearing Capacity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Field Investigation ◽  
Design Stage ◽  
Overall Stability ◽  
Joint Quality

The south extension line was constructed as a new part of the Xintai Expressway in Guangdong Province, China. The project required the construction of an embankment over soft soil with a thickness of up to approximately 14.0 m, and prestressed pipe pile was selected for reinforcing the soft soil foundation to increase bearing capacity and reduce settlement. Embankment sliding with a length of approximately 110 m and cracking with a length that exceeded 300 m occurred before the construction of the pavement structure. Field investigation and theoretical analysis results indicate that the safety factor of the overall stability calculated by the existing code methods is overly large, thereby resulting in large design pile spacing, low design bearing capacity provided by single pile, and excessive load shared by subsoil between piles. These results all cause the flow sliding of soft soil between the piles and the bending fracture of some piles. The revised density method can be used to check the stability of flow sliding, and the bending moment of piles should also be checked during the embankment design stage. In addition, perpendicularity deviation and poor joint quality of pile construction also contributed to the reduction of the bearing capacity of the pipe piles and the overall stability of embankment. Reconstruction of additional rigid piles and add pile after drilling holes are adopted in the sliding and cracking sections to reinforce the failed embankment, respectively. The remediation effect was validated by the measured excess pore water pressure, subgrade settlement, and horizontal displacement.

Model Test Research on Horizontal Bearing Characteristics of Close-Ended Valibale Section Pipe Pile

2014 ◽  
Vol 638-640 ◽  
pp. 475-479
Author(s):  
Qing Guang Yang ◽  
Yi Han Chen ◽  
Jie Tian ◽  
Jie Liu
Keyword(s):  
Bearing Capacity ◽  
Load Transfer ◽  
Small Diameter ◽  
Bending Moment ◽  
Horizontal Load ◽  
Foundation Pit ◽  
Pipe Pile ◽  
Diameter Pipe ◽  
Load Displacement ◽  
Constant Section

Base on indoor model tests of three variable section pipe piles and two constant section pipe piles performed in foundation pit,the load transfer mechanism of two kinds of close-ended pipe piles are studied by comparing horizontal load-displacement curves, critical load and bending moment of piles. Results show that horizontal load-displacement curves change slowly and horizontal bearing capacity of valiable section pipe piles will be higher than constant section pipe piles with equal average diameters.Comparing with constant section pipe piles 1# and 2# with equal average diameters, unit volume horizontal critical bearing capacity of 3# and 4# are improved 8.7% and 34.2% respectively and which have different degrees of increse with improvement of valiable section ratio. Moreover,there are two maximum bending moment to valialble section pipe piles insteard of one to constant section pipe piles.To pipe piles 3#,4# and 5#, maximum bending moment ratio of big diameter pipe to small diameter pipe of valiable section pipe pile are 3.13、2.33 and 1.89 respectively. To pipe piles 3# and 4#, maximum bending moments of big diameter pipe are improved 26.8% and 28.4%.Howeverm,maximum bending moment of small diameter pipe are improved 54.1% and 111.8%.So,it is very clear that valiable section pipe pile is more reasonable than constant section pipe pile in bearing characteristics.

Study on the Bearing Mechanism of Bucket Foundation for Offshore-Wind Turbine in Soft Clay

2011 ◽  
Vol 71-78 ◽  
pp. 1795-1804
Author(s):  
Jian Feng Wang ◽  
Hai Tao Dai ◽  
Ming Qin
Keyword(s):  
Large Scale ◽  
Soft Clay ◽  
Bending Moment ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Horizontal Load ◽  
Vertical Load ◽  
Bucket Foundation ◽  
Finite Element Software ◽  
Moment Load

Based on numerical platform of large-scale finite element software, this paper investigates the function mechanisms of vertical load, horizontal load, and bending moment load of soft-clay-base bucket foundation. Then the corresponding load bearing characteristics of each load type of soft-clay-base bucket foundation are determined.

scholarly journals Numerical Analysis of Bearing Behavior of the Prebored Precast Pile with an Enlarged Base

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Zao Ling ◽  
Jiangbin Wu ◽  
Weidong Wang
Keyword(s):  
Numerical Analysis ◽  
Bearing Capacity ◽  
Soft Soil ◽  
Expansion Ratio ◽  
Construction Technology ◽  
Analysis Model ◽  
Obvious Effect ◽  
Soil Thickness ◽  
Finite Element Software ◽  
Cement Soil

Prebored precast pile with an enlarged base (PPEB pile) is a new type of green and environmental protection pile foundation developed in China in recent years, which has complex bearing characteristics and many influencing factors. Based on the static load tests and key parameters’ tests in deep soft soil in Shanghai, a three-dimensional numerical analysis model was established using ABAQUS finite element software. The transfer law of load among the precast pile, cement soil, and soil around the pile and the action mechanism of the enlarged base were analyzed emphatically, and a sensitivity analysis of the main factors affecting the bearing performance was carried out. The calculation results show that the existence of the enlarged base can greatly improve the compressive bearing capacity, increasing the diameter and height of the enlarged base is beneficial to the bearing capacity, and the influence of the diameter expansion ratio is more effective. With the increase of the proportion of nodular piles, the ultimate bearing capacity increases slightly, but the deformation increases obviously. Under the condition of cement soil of the test piles, the spacing of the neighboring nodules of nodular piles has no obvious effect on the bearing capacity, and the 1 m spacing commonly used in engineering applications can be optimized. The increase of cement soil thickness is beneficial to the improvement of pile bearing capacity, but the efficiency is low. Finally, some improvement measures for the construction technology of the PPEB pile were put forward.

Pile Response Analysis with Unloading Abutment on Soft Ground and Pile Supported Reinforced Embankment Foundation

2014 ◽  
Vol 1065-1069 ◽  
pp. 840-843
Author(s):  
Rong Yao ◽  
Meng Yun Mao ◽  
Yun Que
Keyword(s):  
Finite Element ◽  
Axial Force ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Response Analysis ◽  
Soft Ground ◽  
Finite Element Software ◽  
Pile Response

There ware numeral analysis by ABAQUS finite element software to discover the pile’s status with unloading abutment in soft ground, three model were built, first model was unloading abutment and pile supported reinforced embankment, second model was only unloading abutment, third model was only pile supported reinforced embankment, the piles horizontal displacement, axial force and bending moment were discussed; the results show that the piles horizontal displacement with pile supported reinforced are smaller than the others models, pile axial force in three model are little difference.

Model Test and Finite Element Analysis of Squeezed and Branch Pile Bared Vertical and Horizontal Loads

2013 ◽  
Vol 470 ◽  
pp. 1101-1104
Author(s):  
Yue Hui Li ◽  
Xiao Juan Gao ◽  
Guo Hua Zhong
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Horizontal Displacement ◽  
Horizontal Load ◽  
Vertical Load ◽  
Load Bearing Capacity ◽  
Element Analysis ◽  
Load Bearing ◽  
Practical Engineering ◽  
Vertical Bearing

Model tests of the squeezed and branch pile with or without vertical load are carried out and the horizontal load bearing capacity are studied in this paper. Based on the model test results, the influence of vertical load to squeezed and branch pile horizontal load bearing capacity and the influence of horizontal load to squeezed and branch pile vertical bearing capacity are analyzed with FEM. The analysis results show that the vertical load may increase the lateral bearing capacity of pile, and the horizontal load may decrease the vertical settlement, but horizontal load may increase the horizontal displacement and moment of the pile body and lead to instability and cracking failure. This should be pay more attention in the practical engineering.

scholarly journals Study on Bearing Capacity of Prestressed Pipe Pile Foundation Under Horizontal Load

2017 ◽  
Vol 11 (1) ◽  
pp. 301-312 ◽  
Author(s):  
Jin Xu ◽  
Lin Ma
Keyword(s):  
Bearing Capacity ◽  
Bending Moment ◽  
High Strength ◽  
Horizontal Load ◽  
Horizontal Force ◽  
Pipe Pile ◽  
Steel Bar ◽  
Steel Bars ◽  
Pile Cap ◽  
Group Piles

Background and Objective: Prestressed high strength concrete pipe pile (PHC) shows brittle fracture when subjected to more than its own bearing capacity. Therefore, the non-prestressed steel bar is added to the PHC pipe pile, that is, the mixed reinforced pipe pile (PRC). The mechanical behavior of PRC group piles and PHC group piles under horizontal force is studied, and the bending moment diagram and displacement diagram of the pile body are compared so as to find the weak parts. Material and Method: In this paper, Φ600 pipe piles are chosen, and the PRC pipe piles are made of non prestressed steel bars of the same number as the prestressing steel bars, and the two steel bars are spaced apart. Referring to a specific project of Binhai New Area, the geological parameters are used, and the force analysis of group piles under horizontal force is carried out by using the ANSYS software. Results: ANSYS simulation results show that, under the horizontal loading, when the number of piles in group piles is different, the locations of maximum bending moments are different. Increasing the number of the PRC pipe pile with non prestressed reinforcement can effectively reduce the maximum bending moment of the pile body. Conclusion: Under horizontal load, with the increase of pile number and the pile cap aggrandizement, the position of maximum moment of pile body is shifted from 5-8 times diameter of pile to the top of pile. When the pile number reaches a certain amount, the maximum bending moment will appear at the joint between the pile cap and the pile body. At the same time, increasing the non prestressed steel bar does not influence the bending moment, and the reinforcement of the pile cap and the pile top should be strengthened.

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