大跨半钢板混凝土组合下的仰拱结构疲劳损伤试验研究

发布时间：2018-10-25 17:27

【摘要】：采用疲劳试验,对隧道基底的半钢板混凝土组合仰拱结构试件的疲劳损伤进行了研究。结果表明:在142万次疲劳结束后,试件Z-1沿截面高度钢梁腹板整个被拉裂;在115万次疲劳结束后,试件Z-2腹板全部被拉裂;Z-3试件在疲劳试验循环211万次后,无裂缝产生。试件Z-1、Z-2最小动挠度和最大动挠度随着疲劳加载次数增加有逐渐线性增加趋势,但增加速度较慢,试件Z-3组合梁在达到目标循环200万次前,疲劳破坏未发生。随着疲劳加载次数的增加,试件Z-1的跨中残余挠度先增加后减小再增加,试件Z-2为增加趋势,试件Z-3保持稳定。在临近破坏前,疲劳残余挠度对试件影响较大。试件Z-1、Z-2、Z-3在荷载分别大于100、50、150 k N时,底面钢板应变增加较快。在整个挠度中,试件组合梁最大疲劳残余挠度平均百分比为7.5%,对于隧道基底的半钢板混凝土组合仰拱等承受动荷载结构,由于重复荷载引起组合梁的挠度变形应当重视。
[Abstract]:Fatigue test was used to study the fatigue damage of semi-steel plate concrete composite inverted arch structure of tunnel foundation. The results show that the Z-1 of the test piece is cracked completely along the web of the cross-section height steel beam after the end of 142m fatigue. After 115,000 fatigue, the Z-2 web of the test piece is cracked, and the Z-3 test piece has no crack after 211 000 cycles of fatigue test. The minimum dynamic deflection and maximum dynamic deflection of the test piece Z-1 and Z-2 increase linearly with the increase of fatigue loading times, but the increase speed is slow. The Z-3 composite beam of the test piece does not occur before the target cycle is 2 million times. With the increase of the number of fatigue loading, the residual deflection of Z-1 of the test piece increases and then decreases, the Z-2 of the test piece is increasing, and the Z-3 of the test piece remains stable. Before the damage, the fatigue residual deflection has a great influence on the test piece. When the load of Z-1, Z-2 and Z-3 is greater than 100, 50, 150k N, the strain of bottom steel plate is increased faster. In the whole deflection, the average percentage of the maximum fatigue residual deflection of the composite beam of the test piece is 7.5%, and for the semi-steel plate concrete composite inverted arch of the tunnel foundation, the dynamic load structure is subjected to dynamic load structure, and the deflection deformation of the combined beam due to repeated load should be paid more attention.
【作者单位】：长春建筑学院;北京建筑大学;
【分类号】：U451.5

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