体外预应力钢束在汽车活载作用下的应力变幅分析

利用研发的体外预应力混凝土桥梁结构弹性阶段非线性分析专用程序 ,对几种典型跨径体外预应力混凝土梁桥的体外预应力钢束在汽车活载作用下的应力变幅进行分析。研究了简支梁中结构跨高比、体外预应力钢束与结构的粘结关系、转向块间距等参数对计算结果的影响 ,以及连续梁中施工方案、体内钢束和体外钢束的配束比例、连续跨个数和钢束布置形式等参数对计算结果的影响。同时也与相同条件下的传统体内预应力结构的预应力钢束的应力变化幅度进行比较。这项研究是体外预应力钢束体系疲劳评价研究的一部分。

AN ANALYSIS OF THE STRESS VARIARIONS IN THE EXTERNAL TENDONS OF A PRESTRESSED CONCRETE BEAM BRIDGE UNDER LIVE LOAD

By using a computer code specifically developed for externally prestressed concrete bridges, the stress variations in the external tendons of several typical spans are analyzed. For externally prestressed concrete simply snppoited beam bridges,disscussions are conducted on the influences of span depth ratio, bonding between external tendons and bridge structure,spacing between deviators to the calculation results.For externally prestressed concrete continuous beam bridges, the influences of construction method, ratio of external tendons to internal tendons,number of continuous spans,and layout of external tendons to the calculation results are also discussed.Comparisons are also made with the results of traditional internally prestressed concrete bridges under smilar construction. This serves as part of a research program for evaluation of the fatigue of external prestressing tendon systems.