铁路桥梁高墩适应性研究

Research on the Adaptability of High Pier Railway Bridge

研究目的：艰险山区修建铁路，需要跨越深沟峡谷，必然出现大量的高墩大跨桥梁。随着新建铁路运行速度及墩高的增加，为满足桥梁动力性能，针对山区地形地质特点，采用不同的高墩型式，对墩身工程数量及经济指标影响较大。本文重点围绕铁路桥梁高墩的墩型适应性展开研究，掌握不同类型高墩的受力特点、合理墩高适用范围以及经济指标等。研究结论：（1）提出了不同高墩墩型的经济合理的适用范围：当墩高H≤80m时，应首选单坡空心墩；当墩高100m〉H〉80m时，扫帚型墩经济性更优；当墩高H〉100m时，A型（含人字）桥墩具有明显的经济优势；人字墩适宜于墩高在100－120m的高墩梁桥，当墩高大于120m时，宜首选A型高墩。（2）提出了针对艰险山区不同地形地质条件下A型（含人字）墩基础合理采用形式：对于地形坡度相对较陡、地质相对较好的场地，可采用不等高A型斜腿的分离式基础；对于地形坡度相对较缓、地质相对较差的场地，可采用A型墩哑铃型基础或整体式基础。（3）本文研究成果对艰险山区铁路桥墩墩型的合理选用具有指导意义。

Research purposes： For the railway across dangerous mountainous area where there are deep canyons, a large number of long - span and high pier bridge is necessary. With the increase of running speed of newly - built railway and height of pier, in order to meet the dynamic performance of bridges, the selection of different types of high pier according to engineering geological characteristics of mountainous terrain is more important to reduce work quantities of pier and to optimize its economic indicator. In this paper, a study is made on the adaptability of high pier for railway bridge to master the mechanical characteristics, application range of rational height and economic indicator of different types of high piers. Research conclusions ： （ 1 ） This paper puts forward the economical and reasonable application scope of different high pier types ： when H ≤80 m, single slope hollow pier should be the first choice ; when 100 m 〉 H 〉 80 m, the broom - type pier is more economical; when H 〉 100 m, A - type （including herringbone ） pier has obvious economic advantage; herringbone pier is suitable for high pier bridge with a height of 100 - 120 m, when H 〉 120 m, A -type high pier should be the preferred choice. （2） Choice of reasonable foundation type for A -type （including herringbone） pier under different geological conditions in the mountainous areas： for the location where topographical slope is relatively steep and geologic condition is relatively good, A -type slant -legged separated foundation with unequal height may be used; for the location where the topographical slope is relatively gentle and the geological condition is relatively poor,A -type pier dumbbell foundation or monolithic foundation may be used. （3） The research achievement in this paper has a guiding significance to rational selection of pier type of railway bridge in the dangerous mountainous area.