针对预应力混凝土矮塔斜拉桥的特点,提出了基于索梁权矩阵的索力优化方法,该方法的思路是以主梁截面上下缘的正应力为控制条件,给出主梁截面恒载弯矩可行域和应力可行域,即将《公路桥规》中规定的设计强度值减去活载作用在主梁截面活载应力包络值,使其落在主梁截面应力可行域内.并提出单位荷载法,采用最小二乘法原理,以索梁权矩阵为优化目标,来解决优化索力和预应力优化配置问题,使主梁上下缘的正应力位于上述可行域内.采用TCL语言编程实现了这一方法并进行了实桥算例验证.研究表明,采用该法主梁截面的应力可落在可行域内,从而解决索力和预应力优化配置问题,能使主梁受力处于最优状态.
Aiming at the mechanical behavior of prestressed-concrete extradosed cable stayed bridge,a new method based on cable/girder weight matrix is put forward to optimize the cable force.The method followed the idea that the normal stress on the top and bottom of girder section are controlling condition;and the feasible region of the dead moment and stress are deduced.The design strength of the code for the highway bridge is subtracted the live load envelope,which can meet the stress feasible region of girder section.Unit-load method is put forward,and the least square principle is adopted to optimize cable force and prestressing force.The method is materialized with TCL language and the optimization theory is examined on a real bridge.The results indicate that main girder section stress meets the feasible region by the above method to optimize the cable force and prestressing force;and the main girder can reach the optimal state.