全模块化铝制天桥下部结构设计与力学分析

Modularized design and mechanical analysis of aluminum alloy footbridge pier-foundation system

为了解决目前现存人行天桥桥墩设计过于保守,未能充分利用铝合金材料自重轻的优点,以及城市管网密集布设导致的城市地下结构施工困难等问题,结合钢材和混凝土2种材料的特性,采用钢材降低桥墩材料用量,并采用灌浆套筒、预埋件和螺栓锚固的连接方式,提出一种具有轻量化、模块化、拼装简单的新型全模块化铝制天桥桥墩;通过与传统独柱式桥墩对比,分析结构的力学性能,对桥墩的承载力水平、基础对土体的影响范围等方面进行研究。有限元数值分析结果表明,新型结构的承载能力高于传统结构,在减少材料消耗的基础上保证了结构的可靠性;基础的数值模拟结果表明,微型群桩承台基础对土层的影响范围小于桩柱式基础,有利于减小施工时城市管网造成的施工困难。

In view that the pier design of the existing pedestrian bridge in China was too conservative,the advantages of light weight of aluminum alloy materials was not fully used and the difficulties of urban underground structure construction was caused by the dense layout of urban pipe network,combining the characteristics of both steel and concrete materials,reducing the amount of abutment materials through steel;and by using the connection method of grouting sleeves,pre-embedded parts and bolted anchors,a new type of fully modular aluminum flyover abutment with light weight,modularity and simple assembly was proposed.The mechanical properties of the structure were analyzed by comparing it with the traditional one-column piers,in terms of the level of bearing capacity of the pier and the range of influence of the foundation on the soil.The finite element numerical analysis shows that the bearing capacity of the new structure is higher than that of the traditional structure,which ensures the reliability of the structure based on reducing material consumption.The numerical simulation results of the simulated foundation show that the influence of micro pile-cap foundation is less than the pile foundation,which is beneficial to reduce the construction difficulties caused by the urban pipe network.