闽南山区薄壁空心高墩滑模构造力学特性分析

Mechanical Characteristics and Construction Technology of Slipform Structure of Thin-walled Hollow High-rise Piers in the Mountainous Area of Southern Fujian

针对薄壁空心高墩滑模施工安全问题,以莆炎高速公路下坂1号大桥工程为依托,研究了薄壁空心高墩滑模构造力学特性;建立了槽形拼合截面、加劲肋板临界应力、桁架弹塑性屈曲承载力与墩顶侧移的计算方法;运用有限元软件Midas-Civil,建立了滑模最不利荷载下的有限元模型;分析了主操作平台铺板、钢桁架、模板、提升架、辅助平台铺板、吊杆的内力与变形。结果表明:滑模系统各组成构件内力和变形值均在规定范围内;墩高较低时墩顶侧移主要受施工缺陷控制,相同墩高时施工缺陷越大墩顶侧移越大。依据该研究成果开展墩身线形监测,现场监测结果显示,高墩线形在规定范围内,验证了该方法的正确性与合理性。研究成果可供类似工程参考。

Aiming at the safety problem of the slipform construction of thin-walled hollow high piers, based on the Xiaban No.1 Bridge project Putian-Yanling Expressway, the mechanical characteristics of the slipform structure of the thin-walled hollow high-rise piers were studied. The calculation methods were established for troughed split sections, critical stress of stiffener plates, elastoplastic buckling bearing capacity of truss and lateral displacement of pier top. Used the finite element software Midas-Civil, the finite element model of the sliding form under the most unfavorable load was established, the internal force and deformation of the main operating platform decking, steel truss, formwork, lifting frame, auxiliary platform decking and boom were analyzed. The results show that the internal force and deformation of each component of the slipform system are within the specified range. When the pier height is low, the side displacement of the pier top is mainly controlled by construction defects. When the pier height is the same, the larger the construction defect, the greater the side displacement of the pier top. According to the research results, the pier line type monitoring was carried out. The on-site monitoring results show that the high pier line type is within the specified range, which shows the correctness and rationality of the method in this paper. The research results can be used as a reference for the same type of projects.