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１９ ５ ８年进行了新型 １６公尺跨度的混合桁架（上弦杆力劲性钢筋混凝土，下弦杆为高强 钢丝予应力的重型杆件，腹杆为普通重型钢杆件）的试验研究。本报告包括试验桁架的设计，制 造，试验过程，试验结果和经济分析等部分。 考虑到实际结构的安装程序，荷载分三阶段叠加，即：安装荷载阶段，设计使用荷载阶段和 超载阶段。从各加载阶段的桁架垂度与应力的关系看，证明计算方法是正确的。 试验证明了桁架工作性能良好，在１４０％的设计使用荷载以内，桁架属于弹性工作阶段。之 后，力弹性塑性工作阶段。加载至１８０％设计使用荷载时，桁架频于破坏，设计安全度得到予期 的保证。 从试验看出：单杆予应力桁架用所设计的结点钣连接，能保证结构正常工作。劲性钢筋混凝 土弦杆与钢腹杆共同作用情况正常，半环形和普通承压结点钣的传力性能良好。 从原设计之６ ２公尺桁架作了经济分析比较，若钢材用Ｓｔ ５２，则混合桁架比全钢桁架可节 约钢材达４０％。
In 1958, a new type of hybrid truss with a span of 16 meters (the upper reinforced concrete of the upper chord, the lower chord was the heavy bar with high strength steel wire and the ordinary heavy steel bar with the web) was tested. This report includes the design, manufacture, testing process, test results and economic analysis of the test truss. Taking into account the actual structure of the installation process, load superimposed in three phases, namely: the load phase, the design uses the load phase and overload phase. According to the relationship between the truss sag and stress in each loading stage, the calculation method is proved to be correct. The test proved that the truss work well, within 140% of the design load, the truss belongs to the flexible work stage. After the force flexible plastic working stage. Loaded to 180% design load, the truss frequently destroyed, the design safety is guaranteed. From the test we can see that the single-pole prestressed truss is connected with the designed junction plate to ensure the normal operation of the structure. Strong reinforced concrete chords and steel webs work together normally, semi-circular and ordinary bearing pressure of the sheet metal transmission performance is good. From the original design of 62m truss for economic analysis and comparison, if the steel St 52, the hybrid truss than steel truss can save up to 40% of the steel.