Study On Damage And Failure Of Vertical Piles By Breaking Waves

The pile foundation has the advantages of high bearing capacity,stable working performance,overcoming complex adverse geological disasters,and effectively controlling settlement and uneven settlement of buildings.In particular,bored piles are widely used in civil engineering and hydraulic engineering because of their simple construction equipment,convenient operation and high cost performance.Typhoons frequently occur in coastal areas of southern China,and huge waves caused during typhoons continue to hit coastal and offshore engineering buildings.In particular,the tongue portion of plunging breaking wave has a huge energy,and when it acts on the structure,it will have a huge horizontal impact on the structure.Although many scholars have proposed the impact force formula of the plunging breaking wave on the pile structure,most of them are still focused on hydrodynamic the test.There has been no research on structural response to date,which has brought certain difficulties to the safety assessment of structures under extreme sea conditions.Therefore,it is especially important to study the damage of the pile-column structure to the pile-column structure.The research results can provide reference for the safety design and evaluation of the project.This paper first introduces the principle and application of the constitutive model and mesh division applied in the ABAQUS finite element.Then the ABAQUS finite element is used to establish the pile model model under the horizontal load to simulate the existing physical model test conditions.The displacement of the pile top and the experimental results are verified and compared,which proves the correctness and feasibility of the numerical simulation.Through research and analysis,the following conclusions are obtained:1.In a petrochemical wharf project in Guangdong,there are straight piles and inclined piles in the form of pile foundations.The type is steel pipe piles,and the soil quality is soft.Between 2014 and 2018,several typhoons were encountered,causing the steel pipe pile to break and dump.According to the wave data of this project,the regularity and cause of the analysis results of pile-based concrete damage,concrete structure crack cracking,reference point horizontal displacement and soil yielding under three working conditions are studied.The results show that as the wave height increases,the damage area of the structure increases,and the horizontal displacement of the reference point increases.2.According to the geotechnical investigation data,wave design data and dock structure design data of a petrochemical terminal project in Guangdong,the failure mechanism of the steel pipe pile during the typhoon in recent years is analyzed.The analysis results show that the phenomenon of fracture and dumping of the steel pipe pile in this project is likely due to the fact that the sea surface under the typhoon conditions hits the top of the steel pipe pile and the bending moment at the mud surface is too large,thus destroying.3.In order to study how to improve the horizontal bearing capacity of bored piles under the action of plunging breaking wave,the horizontal bearing capacity of pile foundations affecting ocean and coastal engineering is studied from two aspects: pile foundation parameters and soil parameters.The bearing capacity of the pile foundation is studied by the following six influencing factors: “pile concrete strength”,“pile top restraint(displacement constraint,corner restraint)”,“pile reinforcement ratio”,“pile free length” and “inside friction angle " and " earth modulus of elasticity”.The analysis results show that the increase of pile reinforcement ratio is the most obvious effect on the bearing capacity of pile foundation.The length of the free section of the pile directly affects the area of the pile on the pile,and the smaller the free section of the pile,the smaller the damage.In summary,in the project,the reinforcement ratio of the bored pile can be appropriately increased and the length of the free section of the pile can be reduced to improve the horizontal bearing capacity.