The paper gives yielding conditions and discusses the influence of pre-tension of clamps on yieldable capacity of the U-steel and change of yieldable capacity in the process of yielding.

• 本文给出了U型钢可缩性支架的缩动条件，讨论了卡缆预紧力对支架抗缩动能力的影响以及支架在缩动过程中抗缩动能力的变化等问题。