Research On Optimization Of Design,Construction And Stability Of Bottom-expanded Piles

The strong development of urban construction and the close combination of urban and rural integration are urgently promoting the development of large-scale infrastructure,the large amount of structure and the construction of large buildings,and the superimposed load caused by the upper structure has promoted the development of the underground strong support system at the same time.Due to the need of reality and actual engineering,the Manual digging hole bottomed pouring pile was created.The manual digging hole bottomed pouring pile has gained a foothold in this competitive era for its unique regional advantages.The development and application of the Manual digging hole bottomed pouring pile are still controversy both at home and abroad so far from the development,on the one hand,it gets a lot of engineers,love for its low cost,simple construction technology and simple equipment,on the other hand,the use of manual digging hole bottomed pouring pile is limited in some areas due to the manual digging hole bottomed pouring pile belongs to underground concealed work,requiring the underground workers,and it may encounter some emergency that cannot be predicted in advance which would threaten the safety of workers.So how to better manage and implement the pile foundation is a problem that needs to be solved immediately.It can be known from the initial design to the final inspection that each step is related to whether the pile foundation is stable,whether it is safe,and whether the life safety of construction workers can be guaranteed through the analysis of the design,construction,management,and inspection of the manual digging hole bottomed pouring pile.This paper analyzes several main factors that affect the quality and stability of the pile foundation by starting with the pile foundation design,construction technology,pile foundation safety,pile foundation detection and the common defect analysis and treatment measures.First of all,the theoretically analyzing of the factors affecting the pile foundation in thedesign boil is down to: the size of the pile foundation and the geological environment;the influencing factors in the construction boil is down to:sudden geological conditions and construction processes;the influencing factors in the detection boil is down to: detection methods and analytical method.Therefore,the theoretical calculations are used to analyze the design of the pile foundation under the premise of satisfying the original requirements of the pile foundation,and analyzing the factors that affect the stability and safety quality of the pile foundation based on the obtained conclusions,and analyzing the stability of the pile foundation construction.In this paper,using the mechanical properties of the pile foundation to calculate the mechanical properties of the Manual digging hole bottomed pouring pile,and using finite element numerical simulation of the MIDAS/GTS to obtain the vertical effect of the pile foundation by establishing a three-dimensional space model.Generating the strain cloud map and displacement cloud map during force,and the displacement and strain by the interaction between pile and soil,and this value is compared with the actual value of the original project to explore the mechanism of vertical settlement and failure of the pile foundation,and used to the further verify the correctness of the design plan.Analyzing the design principle and construction technology of the enlarged pile head through the analysis of the original construction plan of the pile base expansion head,according to the specific engineering examples.Redefining the angle of manual digging hole bottomed pouring pile for sand,rock and clay,and applying this conclusion to the project and achieving a better construction effect and economic benefits.For taking into account the difficulty of the construction of the expanding head,the factors affecting the entire pile foundation stability and the factors affecting the safety of underground operators on the basis of the analysis of the original plan,so the original expansion head construction method:support column + steel pipe method and the special template method was used for analysis,and optimization and to be improved on the basis of it,and a new type of expanding head construction method was established.Thismethod combines the advantages of the original construction method and eliminates the disadvantages.It not only facilitates construction,but also increases visibility,and it also improves construction safety and reduces costs after optimization.At the same time,this method has certain limitations,the adjustment of materials and operations can be carried out in combination with different situations in order to achieve better application in the actual project.Many factors that determine the stability and safety quality of the pile foundation have been identified through the construction and testing analysis of manual digging hole bottomed pouring pile.And the factors that affecting the stability of the piles have been concluded through the optimization of construction and inspection,combined with geotechnical engineering investigation and pile foundation testing.A complete set of evaluation index system for the stability of manual digging hole bottomed pouring pile was established in order to evaluate the stability of the pile foundation during construction based on the Pythography and MATLAB.It is possible to conduct more detailed and more standardized management and evaluation of the construction of manual digging hole bottomed pouring pile through the practice of this index system.At the same time,the established evaluation system has a certain degree of universality.The indicator layer and weights can be adjusted in conjunction with different situations,and better application can be achieved in practical projects.