在钢筋混凝土圆管中,拉应力最大的位置是在管截面顶部和底部的内沿以及两侧的外沿,因而有时沿管周不匀称地布置钢筋,以期经济地利用钢材。为此,环向钢筋通常是绕成椭圆形的。值得注意的是:这种管子必需安置在恰当的基座上。如所指出,这种管子不应当安置在混凝土基座上,这是由于其管壁抗弯强度在露出混凝土座的地方(拱脚),可能不足以抵抗该处的弯矩的缘故。本文试图从理论上阐明其严重的程度。在垂直荷载作用下,管子将变形成椭圆形,而且在混凝土基座上,管子底部趋向于离开管座;如果管身与基座之间有良好的结合,则可以阻止这种趋势,同时管子埋入部分与基座 In the reinforced concrete pipe, the place with the largest tensile stress is the inner edge and the outer edge on both sides of the top and the bottom of the pipe section, so sometimes the steel bars are arranged unevenly along the pipe circumference in order to utilize the steel economically. For this reason, hoop reinforcement is usually oval-shaped. It is noteworthy that this tube must be placed on the right base. As noted, such pipes should not be placed on concrete foundations because of the flexural strength of the walls of the concrete where the concrete blocks are exposed (arch) which may not be sufficient to resist bending moments there. This article attempts to elucidate the extent of the problem theoretically. Under vertical load, the tube will deform into an oval shape, and on the concrete base, the bottom of the tube tends to leave the tube seat; if there is a good bond between the tube body and the base then this tendency can be prevented while the tube Embedded parts and base