翼缘板连接的管幕结构抗弯性能的影响研究

Study on mechanical properties of flange connected forms of pipe roofing structure

STS(Steel Tube Slab)管幕结构是一种用于修建地铁站,下穿有隧道、道路、铁路的新型地下支护体系,它是采用混凝土、翼缘板、螺栓将若干个钢管连接起来,形成一个共同受力的支护结构。但STS管幕工法仍存在不足,在STS管幕结构的基础上加以改进,并采用有限元软件研究了翼缘板连接的管幕结构受弯性能的影响。结果表明:钢板连接形式的管幕结构,在一定范围内,极限承载力和横向刚度随混凝土强度的提高而增加较小;翼缘板厚度的增加对横向刚度影响较小,但对极限承载力影响较大,翼缘板厚度每增加1mm,极限承载力提高16.67k N左右;上下翼缘板间距对构件的极限承载力影响较大,翼缘板间距每增加50mm,极限承载力增加100k N左右。

STS(Steel Tube Slab)structure,which is a coupling of concrete,flange,bolt and tube to significantly improve flexural and lateral stiffness of STS structure,is a new technique of underground excavation construction,and applied to build subway stations,underneath existing tunnels,roads and railways.However,the technique has some shortcomings.In current study,pipe roofing method is improved on the basis of STS,and the finite element models are proposed to study the influence of flange connection on flexural behavior of pipe roofing structure.Results obtained indicate that concrete strength grade has unconspicuous influence on the ultimate capacity and lateral stiffness of pipe roofing structure.The flange thickness has a little influence on the lateral stiffness,but the ultimate capacity can be effectively improved.The ultimate capacity increase about 16.67k N with flange thickness rising every 1mm.The flange distance has an obvious effect on flexural capacity,and the ultimate capacity can be improved approximate 100k N when flange distance increases every 100mm.