水温影响下有压水工隧洞结构稳定分析

丁少超 王亦陈

摘 要：为解决运行期有压引水隧洞温度荷载和均匀内水压力联合作用下的应力计算问题，采用有限元法分析隧洞运行期水温变化所产生的温度应力对衬砌应力场与应力极值的影响，通过ANSYS Workbench进行有限元分析，计算运行期不同水温影响条件下的应力分布情况，并对比了弹性力学法计算的温度应力极值。计算结果分析表明，在隧洞运行期混凝土水化热基本稳定后，水温为温度应力的主导条件，水温升高会增大衬砌径向拉应力。因此，对于夏季高温地区或高水温地区需调整隧洞衬砌的配筋，以适应水温产生的温度应力对隧洞衬砌结构的影响。

关键词：水工隧洞;温度场;温度应力;应力分析; ANSYS Workbench 有限元软件

中图分类号：TV651 文献标志码：A

doi：10.3969/j.issn.1000-1379.2020.10.034

Stability Analysis of Pressurized Hydraulic Tunnel Under the Influence of Water Temperature

DING Shaochao， WANG Yichen

（Zhejiang Water Conservancy and Hydroelectric Power Consulting Center， Hangzhou 310020， China）

Abstract：Aiming at the stress calculation under the combined action of temperature load and uniform internal water pressure in the pressurized water tunnel during operation， the influence of temperature stress generated by the water temperature change during tunnel operation to the stress field and stress extreme value of the lining was analyzed by finite element method. The finite element analysis was carried out by ANSYS Workbench to calculate the stress distribution under the influence of different water temperatures during operation and compared the extreme values of temperature stress calculated by the elastic displacement harmonic method. The analysis shows that after the concrete hydration heat is basically stable during the tunnel operation period， the water temperature is the dominant condition of temperature stress， and the increase of water temperature will increase the radial tensile stress of the lining. Therefore， it is necessary to adjust the reinforcement of the tunnel lining in the summer high temperature area or high water temperature area to adapt to the influence of the temperature stress generated by the water temperature to the tunnel lining structure.

Key words： hydraulic tunnel; temperature field; temperature stress; stress analysis; ANSYS Workbench FEM software

在水工隧洞設计中，经常遇到有压隧洞在温度荷载和均匀内水压力联合作用下的应力计算问题[1]。近些年发展起来的抽水蓄能电站和引水式电站，其洞径往往较大、地质条件相对复杂、埋深较深，因此温度应力计算问题变得更为突出。虽然国内外对大体积混凝土工程的温度应力研究较为重视，理论也日渐成熟，但是对于隧洞混凝土衬砌薄壁型结构的温度应力研究较少，且没有得到足够的重视[2-8]，在现有的规范中也没有给出相应具体温度应力的计算方法。在实际工程中许多混凝土衬砌出现了由温度应力引起的裂缝，特别是对于有压引水隧洞，在温度应力与内水压力联合作用下引起应力叠加，使得隧洞衬砌的总应力水平提高，从而影响隧洞的安全稳定性[9]。……