余洋, 李治, 肖龙山, 耿松源, 钱凯. 边柱失效后预应力拼接连接装配式结构抗连续倒塌机理研究[J]. 工程力学, 2021, 38(4): 159-168. DOI: 10.6052/j.issn.1000-4750.2020.06.0366
引用本文: 余洋, 李治, 肖龙山, 耿松源, 钱凯. 边柱失效后预应力拼接连接装配式结构抗连续倒塌机理研究[J]. 工程力学, 2021, 38(4): 159-168. DOI: 10.6052/j.issn.1000-4750.2020.06.0366
YU Yang, LI Zhi, XIAO Long-shan, GENG Song-yuan, QIAN Kai. LOAD RESISTING MECHANISM OF PRECAST STRUCTURE UNDER EXTERIOR COLUMN FAILURE[J]. Engineering Mechanics, 2021, 38(4): 159-168. DOI: 10.6052/j.issn.1000-4750.2020.06.0366
Citation: YU Yang, LI Zhi, XIAO Long-shan, GENG Song-yuan, QIAN Kai. LOAD RESISTING MECHANISM OF PRECAST STRUCTURE UNDER EXTERIOR COLUMN FAILURE[J]. Engineering Mechanics, 2021, 38(4): 159-168. DOI: 10.6052/j.issn.1000-4750.2020.06.0366

边柱失效后预应力拼接连接装配式结构抗连续倒塌机理研究

LOAD RESISTING MECHANISM OF PRECAST STRUCTURE UNDER EXTERIOR COLUMN FAILURE

  • 摘要: 为了研究边柱失效工况下预应力拼接连接装配式结构的抗连续倒塌机理,在实验室开展了4个1/2缩尺预制梁-柱子结构模型试验。试验采用静载方式研究了3种预制装配式连接类型的抗连续倒塌性能。试验结果表明:采用不同连接类型的预制装配式子结构表现出不同的破坏模式;预应力拼接连接是一种有效抵抗连续倒塌的连接方式;采用混合连接结构抗力总是大于或等于钢绞线与角钢连接单独连接抗力之和;较高初始预应力可以增大试件在小变形阶段的抗力,但是会明显降低其大变形阶段的抗力。最后,通过商用有限元软件ANSYS/LSDYNA建立有限元模型,并在验证模型之后分析了试验中没有量测的关键结果,比如梁端弯矩变化,随后对关键设计参数开展了拓展参数分析。有限元结果表明:采用有粘结预应力较无粘结预应力结构抗力提高明显。当增大混凝土强度时,结构抗力也会随之提升。增大轴压比,会加重边柱的P-Δ效应,从而降低结构的变形能力和极限承载力。

     

    Abstract: In order to study the anti-continuous collapse mechanism of an unbonded post-tensioning precast structure with prestressed spliced connections under the condition of side column failure, four one-half scaled precast beam-column substructures were tested in the laboratory. The performance of three types of precast beam-column connections are investigated by using a pushdown loading approach. The test results demonstrated that different connection types exhibit different failure modes. The installation of unbonded post-tensioning connections is an effective way to resist the progressive collapse of precast concrete frames. The hybrid connection achieved greater load resistance than the summation of the load resistance of the unbonded post-tensioning connection and steel angle connection individually. Higher effective prestress in unbonded post-tensioning tendons could increase the load resistance in a relatively small deformation stage. However, the higher effective prestress may decrease the ultimate load capacity of the frame at a large deformation stage. Finally, high-fidelity finite element models, which were relied on commercial software ANSYS/LSDYNA, were developed. After validation, the results, which could not be measured during tests, were presented and discussed. Then, parametric studies were carried out based on the validated models. The numerical results showed that bonded post-tensioning tendons could increase the resistance of the specimen with unbounded post-tensioning tendons. Increasing the concrete strength could also increase the load resistance significantly. However, higher axial compressive forces at side columns will aggregate the P-Δ effects, which leads to lower deformation capacity and ultimate load resistance capacity.

     

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