环锚预应力混凝土衬砌锚索张拉工序优化  

Optimization of Tensioning Process of Tendons in Prestressed Concrete Liner

作　　者：亢景付[1] 王达知 

机构地区：[1]天津大学建筑工程学院,300072

出　　处：《特种结构》2017年第5期87-93,共7页Special Structures

摘　　要：预应力钢筋的张拉工序影响到衬砌施工期的应力状态,可能在衬砌内侧产生过大的轴向次生应力,引起衬砌内侧开裂。锚索分批张拉会造成预应力损失。通过锚索张拉工序的优化,将减小衬砌施工期的轴向应力并减少预应力损失,使衬砌内侧不产生环向裂缝、提高预应力效率且减少锚索张拉次数。采用有限元方法,分析了单束锚索张拉下衬砌的应力状态。在此基础上,对不同工序下锚索张拉施工过程中,衬砌的应力状态和预应力损失情况进行了分析。最终选取张拉工序少、张拉过程中产生的轴向应力较小且预应力损失小的工序作为最优工序。分析结果表明优化后的工序减少了1/3的锚索张拉次数、预应力损失小且产生的轴向最大拉应力约为1MPa,不会使衬砌开裂。为今后类似工程的施工优化提供了参考。The tensioning process of the prestressing tendons affects the stress state during the construction period of the lining, which may cause too high axial secondary stress in the lining and result in cracking on the inner surface of the lining. The tensioning of tendons causes the loss of prestress. By optimizing the tensioning process, the axial stress of the lining and the loss of prestress was reduced and no crackgenerates in the lining.The prestressing efficiency would be improved, meanwhile the tensioning times of the tendons would be reduced. In this paper, the stress state of the lining under the tension of single tendon was calculated with the finite element method. On this basis, the stress state of the lining and the loss of prestress in the tensioning process of tendons under different working procedures were analyzed. In the end, the optimum procedure was chosen as the process with less tensioning times, less axial stress and less prestress loss. By analyzing the results, it was found that the optimized process reduced 1/3 of cable tensioning times, the prestress loss was smaller than unoptimized, and the maximum axial tensile stress was about 1 MPa, which would not cause the lining to crack. It provides a reference for the construction optimization of similar projects in the future.

关 键 词：衬砌 有限元分析 锚索张拉 应力状态 

分 类 号：TU757[建筑科学—建筑技术科学]