Uplift Loading On The Pile Under The Force Of The - Barrels Infrastructure Numerical Analysis

70.8% of the earth's surface area is the sea.The sea is containing the rich petroleum,the natural gas as well as other mineral resources,can provide the massive survivals resources for the humanity.As the development of science and technology,people have the opportunity to find the mining marine resource from the land to the seacoast,even to the distant seas and the deep seas.The sea can satisfy the survival and the life need which the humanity unceasingly grows.In the process of the ocean development,the sea building construction is the first thing must be solved,but all buildings must be established above the appropriate foundation.Pile-bucket foundation in this article research is one kind of new oceanographic engineering foundation.It is being in the fundamental research and the experimental stage at present.This article mainly researched the structure mechanics response of the pile-bucket foundation under the uplift load.This article first used the room cast experiment to carry on the analysis,then used the ABAQUS finite element numerical simulation to carry on the analysis,after carried on the contrast analysis to carry on the analysis to the pile-bucket foundation structure size effect.Firstly,this article had analyzed this topic research vein,including the pile foundation's operating performance,the bucket foundation's operating performance and the ground foundation soil stress characteristic when the pile-bucket foundation under uplift load.This article tried to seek the research direction along these scientific research achievements.Secondly,this article designed the test equipment and the experiment flow to survey the pile-bucket structure distortion under uplift load,carried on the introduction to the experimental principle and carried on the reorganization and the analysis to the test result data.Through the analysis,we knew that the pile-bucket foundation structure stress and the distortion increased along with the uplift load increased,when the uplift load reached the extremely limit,the foundation stress and the distortion also achieved in a big way; After the soil body destruction,each part's stress of the pile-bucket structure tended to stable; The stress of the bucket structure and the pile structure reduced gradually from top to bottom; The top structure of the bucket manifested the solid beam effect in pulling out process; The connection between the top edge of the bucket and the bucket wall tied firmly; In the process of uplift,there would appear the cavity at the bottom of the bucket and the pile,the stress separately reduced 8.6% and 13.5% because of the reduce of the friction force between pile and soil.The stress of the union spot of the pile and the bucket was the biggest in the pulling out process,the value achieved about 3MPa,when the uplift load transmitted from the top to here,it would redistributed; The edge of the bucket would have the bigger stress,the value achieved about 3MPa,the foundation soil body would have the shearing failure in this place.Thirdly,this article utilized the ABAQUS software to establish numerical model, carried on the analysis and the post-processing.According to the stress curves of the 10 measuring points at the pile-bucket foundation,we knew that the pile structure undertook the main resisting force function from step-1 to step-9,the stress growth quantity of the pile structure was 11.0% of its biggest stress value every step and the stress growth quantity of the bucket structure was 1.0% of its biggest stress value every step; The bucket structure undertook the main resisting force function after step-9,the stress growth quantity of the bucket structure was 10.0% of its biggest stress value every step and the stress growth quantity of the pile structure was 1.0% of its biggest stress value every step; This manifested that the pile-bucket structure could increase resists pulling out load compared with single pile structure.This article carried on the contrast analysis between the indoor model experiment tentative data and the numerical analysis tentative data,obtained the basic consistent conclusion and confirmed the feasibility of the numerical simulation method to research the pile-bucket foundation.Fourthly,this article used the ABAQUS software to analyze the stress characteristic of the pile-bucket foundations in different size under the uplift load. According to the analysis,we knew that When destruction load appeared,the foundation soil destruction curve was actually the cone-shape curve,and the curve initial station was not from the pile nose start,but was the certain distance starts above the pile nose where the friction force was the biggest,through the bucket base,to the place surface,formed the cone-shape curve,might infer,soil body destruction face was actually cone-shape curved face; In the bucket flank and around the pile to the foundation axle center the stress of the soil around the pile and the bucket became smaller from near to far in conic-shape,the stress of the soil at 3r(r=radius of the pile)fell 11.3% of the stress of the soil at the face of the pile,the stress of the soil at 0.5R(R=radius of the bucket)fell 19.5% of the stress of the soil at the face of the bucket; the bucket radius change had the biggest influence on the resistance capacity to the uplift load,the buried the pile length change had the second biggest influence on the resistance capacity to the uplift load,the bucket wall high change had the smallest influence on the resistance capacity to the uplift load; When various sizes structure reached the biggest displacement,the foundation soil body influence scope varied,the affect factor of the soil body crosswise scope mainly was the bucket radius,next was buried the pile length,finally was the bucket wall high; the affect factor of the soil body longitudinal scope mainly was buried the pile length,next was the barrel wall high,finally was the barrel radius.Finally,this article carried on the preliminary design to the pile-bucket foundation,proposed the basal step of the pile-bucket structural design.In order to fully display the pile and the bucket combination function of the pile-bucket foundation,buried the pile length and the bucket radius proportion relations should be 8;1 and the bucket radius and the bucket high proportion relations should be 0.6;1.It should add the triangle rib beam at the union spot of the pile and the bucket, it should make the full circle bevel edge at the bucket angle spot to strengthen the structure.The structure mechanics analysis of the pile-bucket foundation under the uplift load had important function for the theoretical analysis and the project practice.