中外隧洞衬砌结构分析方法差异研究

针对厄瓜多尔CCS水电站监理提出采用Bierbaumer理论计算隧洞围岩压力和使用美国规范进行结构分析的要求,结合围岩类别参数,综合分析了岩柱法、太沙基理论、普氏压力拱理论、Bierbaumer理论、国内规范中围岩压力计算差异及各自的优缺点。分析表明,前三种理论不适合于该工程围岩压力分析。提出立足于Bierbaumer理论,同时借鉴国内规范对围岩荷载计算方法进行修正。全面采用美国规范进行地震及非地震工况的结构设计,同时采用SAP2000、ANSYS等有限元软件分析尾水洞特殊部位,如大断面衬砌拐角及拱肩受力过大、洞壁大埋管造成结构厚度削弱、U型断面壁薄等问题。研究认为各关键结构设计满足美国规范各项要求,可供国外类似工程的设计和研究借鉴。

Study on difference of Chinese and foreign structural analysis method of tunnel lining

In CCS hydropower construction in Ecuador, aiming at the Mexican supervisor′s requirement of adopting Bierbaumer theory to calculate tunnel's rock pressure and using American code to guide the design process, according to the parameters of dif-ferent rock type, we make a differences analysis on surrounding rock pressure calculation methods, including the Rock Pillar method, Terzaghi theory, M. M. Promojiyfakonov theory, Bierbaumer theory and domestic standards etc. . The analysis results show the first three methods do not comply with the requirements of the CCS project. We propose to make a correction to the rock pressure calculation method based on the Bierbaumer theory by referring to domestic standards. In the design process, we use A-merican Standard to conduct structural design in seismic and non-seismic case. At the same time, SAP2000 and ANSYS FEM software are applied to analyze the special parts of tailrace tunnel, such as corner part of large section lining, spandrel, weakened wall structure due to buried pipes, thin wall of U section structures. The analysis results show that the structural design meets the foreign standards' requirements, and it is of great guiding significance for the design and research of similar foreign projects.