预应力超静定结构设计方法的改进

Improvement of design method of statically indeterminate prestressed concrete structures

针对目前预应力超静定结构设计方法中存在的不足,结合荷载平衡法与"预应力度法"各自的优点,提出了适合各类抗裂要求的预应力超静定结构的统一设计公式.该公式建立在满足构件抗裂要求的基础之上,考虑了预应力引起的次弯矩的影响以及预应力沿预应力筋长度方向发生变化的影响.利用该公式确定预应力筋量时,计算量小,一般无需返工重算,尤其适合于超静定结构中采用曲线布筋的一般情况.

In light of some shortages lying in the actual design methods of statically indeterminate prestressed concrete structures, and taking advantages of equivalent load method and method based on degree of prestress, a unified design formula is established, which fits for the design of all kinds of statically indeterminate prestressed concrete structures. This formula is based on the satisfaction of requirement of crack resistance, and the influence of the second moment induced by prestress and varying prestress along the tendons is taken into account. Another advantage of this formula is that the computational work can be reduced and especially adapted to the design of structure which has curvilinear tendons.