埋藏光面管抗外压稳定分析的阿姆斯图兹法及其应用研究

Amstutz's method and its application to buckling analysis on plain tunnel linings

针对阿姆斯图兹法(阿氏法)失稳机理和控制微分方程不系统、各国规范采用的迭代公式和工程应用不统一的问题,本文系统推导阿氏法单波失稳机理的控制微分方程组,对比论证了单波失稳机理的可靠性;给出临界外压迭代计算公式的推导假定,剖析了目前常用的4种迭代公式的异同;研究简化临界外压迭代公式选取、缝隙计算与取值、安全系数取值对对抗外压设计方案的影响;指出阿氏论文以及美国ASCE、美国EM引用阿氏公式中的有误处。工程实例分析表明:我国埋藏光面管抗外压设计安全储备相对偏大,建议采用阿氏法临界外压迭代公式和1.5的抗外压安全系数,使安全储备与国际标准基本一致,以适应管道技术进步现状和国际竞争力要求。

In order to systemically illuminate the buckling mechanism and governing differential equation of the Amstutz＇s method（ AM）,and to identify the disagreement among iteration formulas and applications of AM in different codes,the governing differential equations was systematically deduced,and the rationality of the mechanism was investigated. The main assumption in the derivation of iteration formula of critical external pressure（ CEP） was given,and the similarities and differences among the commonly used four types of simplified formulas of CEP were summarized. Theinfluences of selection of iteration formula,gap value,safety factor on the design scheme were studied. The mistakes that presented in AM derivation,ASCE provision and EM provision were listed. Practical examples show that,the safety margin in China provision tends to be larger than that in America and Japan codes. In order to follow the development of pipe construction technology,to improve our international competitiveness and to coincide with international standards,using AM iteration formulas and adopting safety factor of 1. 5 are suggested for plain linings.