钢管混凝土注浆孔补强的短柱轴压试验

Axial Compression Test on Reinforcement of the Pouring Hole on Steel Tube Confined Concrete

钢管混凝土支架在巷道内完成灌注混凝土,因此需要在支架钢管开孔制成注浆孔并进行补强。结合局部补强方式和现场生产经验设计了3种补强措施(注浆短管、加强板、封孔塞)及其参数,并通过等面积补强法进行验证,3种补强措施满足了现场注浆要求,同时保证了开孔补强效果。通过钢管混凝土短柱试件和注浆孔短柱试件的轴压试验,对设计补强措施的补强效果和部分补强参数对注浆孔短柱力学性能的影响进行分析。试验表明,在短柱轴压试验中,注浆孔短柱的变形、荷载与钢管混凝土短柱接近,满足短柱补强的要求;随着封孔塞厚度和加强板厚度的增加,注浆孔短柱极限荷载明显提高,从钢管混凝土支架等强度要求和支架生产成本考虑,封孔塞、加强板的厚度优选25mm、8mm。

Because the Steel Tube Confined Concrete （STCC） supports are built by pouring with concrete in the roadway, and the pouring hole is required on the steel tube of the STCC supports as openings, and should be reinforced. Combining the local opening reinforcement methods with the field production experience, three reinforcement measures are proposed as the pouring short tube, the sealing plug, and the strengthening plate, together with their parameters. By the area replacement method, the three reinforcement measures are shown to meet the grouting requirements in the roadway, as well as to ensure the reinforcement effect. By the axial compression test of STCC short columns and the pouring hole on STCC short columns, the reinforcing effect of the designed reinforced measures and some reinforcement parameters on the mechanical properties of the short column of grouting holes are analyzed. It is shown that the deformation and the load on the grouting hole short column are close to those of STCC short columns by the axial compression test, with the thickness increase of the sealing plug and the strengthening plate, the tested ultimate load on the grouting hole short column is slightly increased, which meet the requirements of the short column reinforcement. From the considerations of the constant strength requirements and the production cost of STCC supports, the thickness of the sealing plug and the strengthening plate are determined as 25ram and 8mm.