铁路薄覆土波纹管涵静力性能试验研究
Experimental study on the static behavior of railway corrugated-steel pipe culvert with thin soil cover
许见超 1董亮 1班新林 1葛凯1
作者信息
- 1. 中国铁道科学研究院集团有限公司 铁道建筑研究所,北京 100081
- 折叠
摘要
针对当前考虑铁路荷载特征的波纹钢管涵力学性能试验成果匮乏的问题,为支撑波纹钢管涵在铁路工程中的应用,开展铁路波纹钢管涵的力学性能研究.试验模拟铁路管涵结构构造,聚焦铁路活载作用响应,开展铁路薄覆土波纹钢管涵静力加载试验.研究结果表明:涵顶覆土0.6 m砂+0.3 m碎石及0.3 m砂+0.3 m碎石时均未出现涵-土脱离,试验覆土厚度能够满足波纹钢管涵发挥土-结构相互作用;但试验中管涵出现局部环拉-弯受力状态.随着覆土高度增加,恒载+活载作用下的管涵应力先减小后增大,本文工况拐点约在填土高度2～3 m;即从管涵受力角度,存在一个最优覆土厚度.随着荷载远离涵顶,管涵最大环向应力位置随之由涵顶向荷载侧45°偏移;当堆载位置在远离涵顶0.3 m位置时,管涵环向应力最大,设计时应考虑荷载偏心工况.随着涵周中砂密实度(弹模)增加,管涵环向应力最大值略有减小,管涵挠度明显减小;其原因应为涵周中砂局部进入屈服状态,故中砂压实度(弹模)对管涵最大应力影响较小,而整体上对管涵挠度响应明显.铁路波纹钢管涵采用公路相关规范的最小覆土厚度时,涵-土不会发生脱离,能够发挥土-结构相互作用;但铁路轨-枕-道床的荷载传递方式易引起管涵出现局部环向拉-弯受力状态,故建议采用更大的覆土厚度.
Abstract
Currently,experimental studies on the mechanical behavior of corrugated-steel pipe culverts considering railway load characteristics are rare.To support the application of corrugated-steel pipe culverts in railway engineering,experimental study is conducted to investigate the mechanical behavior of railway corrugated-steel pipe culverts.The structural configuration of railway culvert is experimentally simulated and static loading tests on railway corrugated-steel pipe culverts are conducted.Thin soil cover is adopted for corrugated-steel pipe culverts to focus on the mechanical response of corrugated-steel pipe culverts under railway live load.The results show that,there was no culvert-soil detachment with soil covers of 0.6 m sand+0.3 m gravel and 0.3 m sand+0.3 m gravel,which means soil-structure interaction is guaranteed;but local stress state of combined circumferential tension and bending was experimentally observed.As the soil cover depth increases,the culvert stress under dead load plus live load first decreases and then increases,and the inflection point in this paper is about 2～3 meters depth;from the perspective of culvert stress,there exists an optimal soil cover depth.As the load moves away from the culvert,the maximum culvert stress position shifts from the culvert top to the load side 45°;when the load position is 0.3 m away from the culvert top,the culvert stresses reach the maximum,and thus eccentric loads should be considered in design.As the compaction degree(elastic modulus)of sand around culvert increases,the maximum culvert stress slightly decreases,while the culvert deflection obviously decreases;the reason should be that the sand around the culvert enters a yielding state locally,so the maximum culvert stress is slightly affected while the overall response at deflection is obviously affected.When the minimum soil cover depth specified in relevant specifications in highway field is adopted for railway corrugated-steel pipe culverts,the culvert and soil will not detach,and thus soil-structure interaction is guaranteed;however,the railway load transfer method of track-sleeper-bed tend to cause a local circumferential tension-bending stress state in pipe culverts,so it is recommended to apply a larger soil cover depth.
关键词
铁路/波纹钢/管涵/试验研究/数值分析Key words
railway engineering/corrugated-steel/pipe culvert/experimental study/numerical simulation引用本文复制引用
基金项目
中国国家铁路集团有限公司科技研究开发计划(J2021G004)
出版年
2024
国家科技期刊平台
NSTL
万方数据