Selection And Optimization Of Communication Tower Foundation

In recent years,with the rapid development of communication technology,the communication industry in our country has developed rapidly,and the related communication tower infrastructure has also been greatly developed.The tower foundation as a part of the tower structure,which has become an important position in the construction of the communication tower.Economic and reasonable foundation design will greatly reduce the difficulty of tower construction,and improve the overall efficiency of the whole tower project.Therefore,this paper focuses on the following two aspects:foundation type selection and optimization design of the communication tower.(1)The comprehensive benefit of various types of tower have been evaluated based on analytic hierarchy process.Firstly,Before the tower design,the foundation type that may be used should be determined.And then,the bearing capacity of the tower foundation,the pulling force,the cost and the engineering geological conditions are selected as the evaluation indexes,and the weight of each index is calculated by the geometric average method.Finally,a practical example is used to selected the foundation type for the two kinds of commonly used tower by this method.The analysis results show that the comprehensive benefit of the communication tower used by digging squeezed branch pile foundation type is more notable than the other two type foundation's.(2)The ABAQUS software is used to establish the excavating squeezed branch pile finite element model,the stress and displacement of the excavating squeezed branch pile in different soil and the characteristics of the stress change of the pile body at different positions of the pile are analyzed.And with the equal diameter pile,the difference of pile top displacement and the soil stress of the two pile foundations are compared.It is concluded that the better the soil properties at the position of the soil layer,the horizontal bearing capacity and uplift capacity of the excavating squeezed branch pile higher is.When the support plate is installed in the middle of the pile body,the horizontal bearing capacity of the pile is the highest.In the two kinds of pile(ordinary pile and digging squeezed branch pile)foundation bearing force and pullout capacity of approximately equal circumstances,compared to the ordinary pile foundation,the digging squeezed branch pile diameter can be reduced by 37.5%,which shows that the digging squeezed branch pile can reduce the project cost effectively,and to maximize the comprehensive benefits of the construction of the tower.(3)The bearing capacity of the pile foundation and the pulling force optimization targets are selected as the optimization targets,the sequential quadratic programming method and genetic algorithm are used to optimize the design.When the support plate size and location are determined,the maximum of the objective function is obtained through the optimization algorithm according to the optimization objective,the optimal pile foundation diameter and height are determined,and the two methods' accuracy of quadratic programming method and genetic algorithm are compared.The results show that the genetic algorithm has higher precision.The results obtained in this paper can provide the basis for the design of the pile foundation of the communication tower.