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| 轻型预应力UHPC锚固局压区设计优化与承载能力研究 |
| Optimization of the Design and Bearing Capacity of the Local Compressive Zone in Lightweight Prestressed UHPC Anchorage |
| 投稿时间：2024-12-17 修订日期：2025-04-15 |
| DOI： |
| 中文关键词: UHPC，锚固局压区，轻型，承压机理，参数研究，承载能力 |
| 英文关键词: UHPC, local anchorage compressive zone, lightweight, bearing mechanism, parametric study, load-bearing capacity |
| 基金项目:国家自然科学基金-青年科学基金项目（52308129）、安徽省自然科学基金-青年项目（2308085QE185）、安徽省BIM工程中心主任基金（AHBIM2023ZR01） |
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| 中文摘要: |
| 预应力桥梁结构中锚固局压区的受压能力关系预应力结构施工过程的安全性和预应力结构体系可靠性。本文首先基于力流模型分析了锚固局压区的局部承压机理,阐明了锚垫板和螺旋钢筋在局部承压中的作用。然后,针对预应力UHPC桥梁结构轻量化与薄壁化的特点,充分发挥UHPC材料优异力学特性,对传统的锚固局压区进行简化,提出了去锚垫板和附加钢筋的轻型UHPC锚固局压区体系。为验证所提轻型UHPC局压区的可靠性,本文建立了7根和12根钢绞线锚固的轻型UHPC锚固局压区试件的有限元模型,通过非线性数值试验获得了其局压承载能力。数值试验结果表明,其局压承载能力是设计所需承载能力的2倍以上。为进一步对所提出锚固局压区设计参数进行优化,本文进行大量参数研究,分析了螺旋筋约束直径,高度、螺距和钢筋直径、UHPC强度,锚板尺寸和UHPC保护层厚度等进行参数对其承载能力的影响。基于参数研究结果,确定了最优UHPC轻型锚固局压区的设计参数并验证了其承压能力。最后,针对所提出的轻型UHPC锚固局压区确定了适合其承压能力的计算公式。 |
| 英文摘要: |
| The compressive capacity of the local anchorage compressive zone in prestressed bridge structures is critical to the safety of the construction process and the reliability of the prestressed structural system. This paper first analyzes the local compressive mechanism of the anchorage compressive zone based on the force flow model, elucidating the role of the anchorage plate and spiral steel bars in local compression. Subsequently, considering the lightweight and thin-walled characteristics of prestressed UHPC bridge structures, and leveraging the excellent mechanical properties of UHPC materials, the traditional anchorage compressive zone is simplified. A lightweight UHPC anchorage compressive zone system is proposed, which eliminates the anchorage plate and additional reinforcement. To verify the reliability of the proposed lightweight UHPC compressive zone, finite element models of test specimens with seven and twelve strands of steel tendons anchored in the lightweight UHPC compressive zone were established. Nonlinear numerical simulations were conducted to determine their compressive bearing capacity. The numerical test results indicate that the compressive bearing capacity is more than twice the required design capacity. To further optimize the design parameters of the proposed anchorage compressive zone, extensive parametric studies were performed. The effects of various parameters, such as the spiral reinforcement confinement diameter, height, pitch, and bar diameter, UHPC strength, anchor plate size, and UHPC protective layer thickness on the bearing capacity were analyzed. Based on the results of the parametric study, the optimal design parameters for the lightweight UHPC anchorage compressive zone were determined, and its compressive capacity was verified. Finally, a calculation formula suitable for determining the compressive capacity of the proposed lightweight UHPC. |
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