通信铁塔基础选型与优化设计

发布时间：2018-05-24 16:41

本文选题：层次分析法 + 基础选型　；参考：《西安工业大学》2017年硕士论文

【摘要】：近些年,随着通信技术的突飞猛进,我国的通信产业发展迅速,与之相关的通信铁塔基础设施建设也有了较大的发展。其中,铁塔基础作为铁塔结构的一部分,在整个通信铁塔的建设中具有十分重要的地位,经济合理的基础设计将会大大降低铁塔的建设难度,节省造价,提高整个铁塔工程的综合效益。为此,本文主要围绕通信铁塔的基础选型与优化设计进行了深入分析研究,具体内容包括:(1)利用层次分析法对铁塔的各类型基础进行综合效益评价。在进行铁塔设计前,首先确定通信铁塔可能采用的基础形式,然后选定铁塔基础的承载力、抗拔力、造价与工程地质条件作为评价指标,采用几何平均法计算各指标的权重,并对铁塔的各类型基础进行综合评价。最后通过一工程实例,利用该方法对两种常用的通信铁塔形式进行了基础选型。分析结果表明,通信铁塔采用挖孔支盘桩基础形式时,其综合效益相比于另外两种基础形式更加显著。(2)应用ABAQUS有限元软件,建立了挖孔支盘桩有限元模型,分析了挖孔支盘桩在不同土层中桩身的内力与变形,支盘设置在桩身的不同位置时桩身的受力变化特点,并对比研究了等直径的一般桩基础与挖孔支盘桩基础在桩顶相同荷载的条件下,两种桩基础的桩身应力、桩顶位移和土体应力的区别和差异。研究结果表明,当支盘所处位置的土层性状越好时,支盘桩的水平承载能力与抗拔能力越高;当支盘设置在桩身中部时,桩身水平承载力最高;支盘在桩身底部时,桩身抗拔力最高。在保持两种桩(普通桩和挖孔支盘桩)基础的承载力与抗拔承载力大致相等的情况下,挖孔支盘桩的桩径相比于普通桩基础可以减小37.5%,说明采用挖孔支盘桩基础能够有效降低工程造价,实现铁塔工程建设综合效益的最大化。(3)以支盘桩基础的承载力和抗拔力为优化目标,利用二次规划法与遗传算法对其分别进行优化设计。在支盘尺寸与位置确定的情况下,根据优化目标,利用优化算法得出了的目标函数最大值,并确定了支盘桩基础最优时桩基础的直径与桩身高度,同时对二次规划法与遗传算法的精确度进行了对比,分析结果表明,遗传算法的精度更高。本文分析所得结果可为通信铁塔支盘桩基础设计提供依据。
[Abstract]:In recent years, with the rapid development of communication technology, the communication industry in China has developed rapidly. Among them, as a part of the structure of iron tower, the foundation of iron tower plays a very important role in the construction of the whole communication tower. Economic and reasonable foundation design will greatly reduce the construction difficulty of the tower and save the cost. Improve the comprehensive benefit of the whole iron tower project. Therefore, this paper mainly focuses on the foundation selection and optimization design of the communication tower, including the specific content of: 1) using AHP to evaluate the comprehensive benefit of each type of foundation of the tower. Before the design of the tower, the possible foundation form of the communication tower is determined, and then the bearing capacity, pullout resistance, cost and engineering geological condition of the tower foundation are selected as the evaluation indexes, and the weight of each index is calculated by the geometric average method. And the comprehensive evaluation of each type of foundation of iron tower is carried out. Finally, through an engineering example, the foundation selection of two common communication tower forms is carried out by using this method. The results show that the comprehensive benefit of the communication tower is more significant than that of the other two kinds of foundation when the communication tower adopts the form of excavated branch and disc pile. The finite element model of the excavated branch disk pile is established by using ABAQUS finite element software. The internal force and deformation of the pile body in different soil layers are analyzed, and the stress characteristics of the pile body are analyzed when the branch disk is located in different positions of the pile body. The difference and difference of the stress of pile body, displacement of pile top and stress of soil of two kinds of pile foundation under the same load on the top of pile are compared and studied. The results show that the horizontal bearing capacity and uplift resistance of the pile are higher when the soil layer in the position of the branch plate is better, the horizontal bearing capacity of the pile body is the highest when the branch plate is located in the middle of the pile body, and the horizontal bearing capacity of the pile is at the bottom of the pile body when the branch disc is located at the bottom of the pile body. The uplift resistance of the pile is the highest. If the bearing capacity of the foundation of the two types of piles (ordinary pile and bored branch pile) is approximately equal to that of the uplift bearing capacity, Compared with the common pile foundation, the pile diameter of the bored branch disc pile can be reduced by 37.5. it shows that the construction cost can be reduced effectively by using the digging hole branch disc pile foundation. In order to optimize the bearing capacity and uplift resistance of pile foundation, the quadratic programming method and genetic algorithm are used to optimize the design. In the case of determining the size and position of the branch disc, according to the optimization objective, the maximum value of the objective function is obtained by using the optimization algorithm, and the diameter and height of the pile foundation are determined when the pile foundation is optimal. At the same time, the accuracy of quadratic programming method and genetic algorithm is compared. The results show that the accuracy of genetic algorithm is higher than that of genetic algorithm. The results obtained in this paper can provide the basis for the design of the communication tower branch-disc pile foundation.
【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU476

【参考文献】