冻结井钢筋混凝土弧形板井壁力学特性研究

通过实验和有限元计算，对在均匀荷载作用下新型冻结井高强钢筋混凝土弧形板井壁的变形特性、混凝土和钢筋应力的分布规律、极限承载力及其压碎区的位置进行了分析。研究结果表明，弧形构件的径向变形较小，可通过选择合适的可缩接头材料使该井壁结构起到“先柔后刚”的作用；弧形构件的内排钢筋总是比外排钢筋先屈服，并且钢筋发生屈服时对应荷载值一般为该构件极限承载力的60 %左右；构件的极限承载力随混凝土单轴抗压强度的增大而增大，混凝土的强度等级提高10 MPa，其极限承载力提高1.26 MPa；弧形构件的压碎区位于其端部附近，因此，在设计该种井壁结构时弧形构件的两端应该加强，可在弧形构件的两端采用钢纤维混凝土以提高整体结构的承载能力。

Study on mechanical characteristics of reinforced concrete arc shaft wall in frozen shaft

For the high strength reinforced concrete arc shaft wall, its mechanical characteristics including the radial displacement, the concrete stress, the reinforcing steel bar stress, the load carrying capacity and the position of crushing zone are analyzed by experiment and finite element calculation under uniform load. The results show that the radial displacement of the arc component is very small. The load under which the reinforcing steel bar is beginning to yield is 60 % of its load carrying capacity. The larger the ultimate uniaxial compressive strength of concrete, the higher is the carrying capacity of the high strength reinforced concrete arc shaft wall. As the strength grade of concrete increases 10 MPa, its carrying capacity raises 1.26 MPa. The crushing zones are both end of the arc component. So we design the arc shaft wall, both end of the arc component must be strengthened with the steel fiber concrete for enhancing the load carrying capacity of the shaft wall.