摘要
通过室内模型试验对3榀不同位置设置可缩接头的U型钢马蹄形封闭可缩钢架进行分级均布加载,并采集不同荷载下钢架不同位置的径向位移及各接头滑移量.结果表明:1)接头滑移速率决定钢架承载力及其变形特性,接头快速滑移时钢架承载力不稳定性增加,让压变形明显;2)封闭可缩钢架接头滑移特性与接头处钢架内力组合有关,随总外荷载的增加,拱顶接头最先发生滑移且速率较快,其次为拱脚接头,拱底接头最难滑移;3)拱顶接头发生滑移时拱顶下沉最为明显,建议当围岩荷载顶压较大时优先在拱顶设置接头;当围岩侧压力较大时,宜在拱底设置接头;4)在不削弱钢架支护力的前提下保证所有可缩接头平稳有效滑移是充分发挥其让压支护性能的关键.
Multi-stage uniform loading were applied to three contractible U-steel enclosed horseshoe-shaped supports with different layouts of contractible joint through the laboratory model tests.The radial displacement at different points of steel-support and the sliding displacement of the overlap joint were recorded.Results show that,slide velocity of overlap joint determines the bearing capacity and deformation properties of the contractible steel-support;the bearing capacity shows more instability and the steel-support has strongly yielding deformation when the overlap joints slide quickly.The sliding characteristic of overlap joint is relevant with the combination of internal force of the joint's location on the enclosed contractible steel-support.With the loading increasing,vault joint slide firstly with high velocity,followed by the foot joint,while the bottom joint is most difficult to slide.The vault sinks remarkably when vault joint slides,so it is suggested that the contractible joint should be placed in the vault when the rock pressure in the vault is great.When the lateral rock pressure is much greater,the bottom joint should be arranged.All the contractible joint should be slid stably and effectively to ensure that the yielding support can work effectively without weakening the supporting force.
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2017年第12期2355-2364,共10页
Journal of Zhejiang University：Engineering Science
基金
国家自然科学基金资助项目(51278233)
交通运输部公路科学研究所基金项目(2015-9033)
关键词
U型钢
马蹄形
封闭式
可缩钢架
让压支护
U-steel
horseshoe-shaped
enclosed
contractible steel-support
yielding support
