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为了研究铰接板桥在疲劳荷载作用下的挠度变化规律,制作了2组钢筋混凝土板桥试件,一组进行疲劳试验,另一组对应地进行静载试验。在试验过程中,分别取疲劳循环达到一定次数后静载作用下的板桥跨中挠度值和挠度残余累加值进行研究,并将疲劳荷载作用后的板桥与只进行静载试验的板桥在静载作用下的跨中挠度变化规律进行对比分析。研究结果表明:当疲劳循环次数未超过200×104次时,由于疲劳幅值未超过特定值,故随着疲劳次数的增加,施加静载时挠度值随静载值的增加逐渐呈线性关系,同时对于不同疲劳次数,施加相同静载时挠度值的变化呈现一定的规律性;当疲劳循环次数达200×104~250×104次,疲劳幅值增大时,挠度随施加静载值的变化规律仍近似呈线性,但在相同静载作用下,挠度值比未超过200×104次时的值增加较多,同时一定幅值下的疲劳循环次数及不同的疲劳幅值均会对板桥的疲劳残余产生影响;由静载试验梁的荷载-挠度曲线的对比可看出,经过疲劳荷载作用后,板桥挠度随施加荷载的变化更接近于线性变化。
In order to study the rule of the deflection of the hinge-slab bridge under the fatigue load, two sets of RC slab bridge specimens were made. One group was subjected to fatigue test and the other group was subjected to static load test. During the experiment, the mid-span deflection values and the accumulated residual deflection values under static load after taking a certain number of fatigue cycles respectively were studied, and the plate bridge after fatigue loading and the plate bridge with only static load test Under static load, the variation of mid-span deflection is compared and analyzed. The results show that when the fatigue cycle does not exceed 200 × 104 times, the fatigue value does not exceed a certain value. With the increase of fatigue frequency, the deflection value at static load increases linearly with the increase of static load. At the same time, for different fatigue times, the change of deflection value shows certain regularity when the same static load is applied. When the fatigue cycle reaches 200 × 104 ~ 250 × 104 times, the fatigue amplitude increases, the deflection changes with the application of static load The law is still approximately linear, but under the same static load, the deflection value increases more than the value of 200 × 104 times, while the number of fatigue cycles and different fatigue amplitude under a certain amplitude will affect the Itabashi The comparison of load-deflection curve of static load test beam shows that the deflection of plate-type bridge is closer to linear change with applied load after fatigue load.