论文部分内容阅读
针对工程中单根预应力锚杆的脱黏失效问题,基于突变理论提出一种研究的新思路。在建立简化力学模型的基础上,推导出锚固界面的非线性剪切滑移模型;视预应力锚杆为弹性体,根据弹性理论得出锚杆的总势能;引入突变理论,将锚杆势函数化简为尖点突变模型的标准形式,构建锚杆失效的临界判据,并进行脱黏分析。结果表明:所建非线性剪切滑移模型可以合理考虑锚固界面的软化特性;拉拔荷载作用下,锚杆杆体与周围注浆体的界面剪应力分布逐渐演化为单峰曲线,直至极限状态下整个锚固界面发生软化破坏;推导出的临界松动位移理论公式简单实用,可为研究单根预应力锚杆的脱黏失效提供参考。通过对工程算例进行验算分析,证明所提方法是合理可行的。
Aiming at the problem of debonding failure of a single prestressed anchor in engineering, a new idea of research based on catastrophe theory is proposed. Based on the establishment of a simplified mechanical model, the nonlinear shear-slip model of the anchorage interface is deduced. As the prestressed anchor is an elastic body, the total potential energy of the anchor is obtained based on the elastic theory. By introducing the catastrophe theory, The function simplification is the standard form of the cusp catastrophe model, and the critical criterion of bolt failure is constructed, and the debonding analysis is carried out. The results show that the nonlinear shear-slip model can reasonably consider the softening behavior of the anchorage interface. Under the action of drawing load, the interfacial shear stress distribution of the anchor rod body and surrounding grout gradually evolves to a unimodal curve until the limit state The entire anchoring interface softens and destroys. The theoretical formula of critical loosening displacement deduced is simple and practical, which can provide reference for studying the debonding failure of single prestressed anchor. By checking the engineering example, it proves that the proposed method is reasonable and feasible.