现浇楼板对钢筋混凝土框架结构在地震作用下破坏形式的影响

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振动与冲击 ›› 2011, Vol. 30 ›› Issue (7) : 227-232.

论文

现浇楼板对钢筋混凝土框架结构在地震作用下破坏形式的影响

阎红霞1,2 ; 杨庆山1; 李吉涛1

作者信息 +

Influence of cast-in-place floor slab on damage style of frame structures under earthquake action

Yan Hong-xia1,2; Yang Qing-shan1

Author information +

文章历史 +

摘要

“5.12”汶川地震造成一些钢筋混凝土框架结构损坏甚至倒塌。灾后调查发现，框架结构震害特点之一是柱端而非梁端出现塑性铰的“强梁弱柱”破坏形式，这与结构抗震设计概念中的“强柱弱梁”不符。国内外研究表明现浇楼板增大了梁端抗负弯承载力，但其对整个框架结构屈服机制的影响研究依然不足。针对这种现象，应用有限元软件ABAQUS对汶川地震中都江堰市某典型“强梁弱柱”框架进行三维动力弹塑性时程数值模拟，着重从结构角度上分析了现浇楼板对框架结构抗震性能的影响、探讨了负弯矩作用下梁端有效翼缘的取值。经分析，发现按照目前我国规范设计的框架在遭遇大震时较难实现“强柱弱梁”屈服机制。框架设计时宜在柱端弯矩增大系数不变的情况下，负弯矩作用下梁端有效翼缘范围内的板筋参与梁受弯，建议该范围取6倍板宽；大震下框架弹塑性变形验算宜采用考虑现浇楼板的计算模型。

Abstract

Many reinforced concrete frame structures were severely damaged or even collapsed during the May 12, 2008 great Wenchuan earthquake. Based on survey data collected in Dujiangyan, it was found that column end, instead of beam end, appeared plastic hinges in many frame structures. This did not accord with “strong column-weak beam” seismic design criterion. It is believed one of the main reasons is insufficient understanding about the cast-in-site floor slab effect on frame structures. Applying finite software ABAQUS, 3D elastic-plastic time history simulation of a “strong beam -weak column” RC frame structure in Dujiangyan is analyzed to probe the influence of cast-in-slab on frame seismic performance from structural view. Results show that RC frame designed following current codes usually can not achieve “strong column-weak beam” yield mechanism. The numerical results suggest the rebar in the width of six times of the plate thickness may be taken into account in calculating the bearing capacity of negative moment at the beam end; the model of frame with floor slab should be applied in analyzing the deflection under rare big earthquakes.

导出引用

阎红霞;;杨庆山;李吉涛. 现浇楼板对钢筋混凝土框架结构在地震作用下破坏形式的影响[J]. 振动与冲击, 2011, 30(7): 227-232

Yan Hong-xia; Yang Qing-shan. Influence of cast-in-place floor slab on damage style of frame structures under earthquake action[J]. Journal of Vibration and Shock, 2011, 30(7): 227-232