大直径密排管幕的力学分析及在地铁车站中的应用

Mechanical Analysis of Large Diameter Dense Pipe Curtain and Its Application in Subway Station

依托沈阳市地铁10号线东北大马路站大直径密排管幕法施工,采用模拟分析结合室内模型试验的方法,分析大直径密排管幕的受力特征。考虑钢筋混凝土等级、钢管间距、翼板厚度以及连接形式对构件承载力的影响,采用数值分析与变形监控量测相结合,研究工法在地铁站施工中的可行性。研究表明:管幕构件在力学性能上要略优于等效厚度的等截面混凝土构件,实际工程设计可采用等截面混凝土梁模型进行简化计算;混凝土等级对大直径密排管幕的承载力具有明显影响,翼板厚度增加引起承载力增加幅度较小,钢管间距对试件的极限承载力影响大于屈服承载力,下翼钢板的存在对试件的屈服承载力和极限承载力影响很大,而钢筋、上翼板、钢筋通长对试件的屈服承载力和极限承载力影响不明显;大直径密排管幕的顶进对地层的变形影响非常小,地表沉降大部分是由于地层开挖造成的。

Based on the construction of large-diameter close spaced pipe curtain in Dongbeidamalu Station of Shenyang Metro Line 10,the stress characteristics are analyzed by combining simulation analysis and laboratory modeling test.Considering the influence reinforced concrete grade,pipe space,flange thickness and connection forms on the bearing capacity,the feasibility of construction method in subway station construction is studied by means of numerical analysis and deformation monitoring measurement.The study shows that the mechanical properties of pipe curtain members are slightly better than those of equal cross-section concrete with equivalent thickness,and the equal cross-section concrete beam model can be used for simplified calculation in practical engineering design.The grade of concrete has obvious influence on the bearing capacity of dense pipe curtain with large diameter,the increase of bearing capacity caused by the increase of flange thickness is small,and the influence of steel pipe spacing on the ultimate bearing capacity is greater than that of yield bearing capacity.The existence of lower wing steel plate has a great influence on the yield bearing capacity and ultimate bearing capacity of the specimen,while the reinforcement,upper wing plate and the length of reinforcement have no obvious influence on bearing capacity.The jacking of large diameter dense pipe curtain has little influence on the deformation of the stratum,and most of the surface subsidence is caused by the stratum excavation.