引黄工程钢筋混凝土岔管应力分析

对山西省引黄工程中的钢筋混凝土岔管高应力的原因进行了分析，认为与围岩边界的温度低、约束力强有很大关系。在缺乏足够水位资料情况下，由于发现了最初通水时有一水位升高而岔管温度不变的极短时段，成功地进行了应力分解。为证实岔管是否处于弹性工作状态，提出用径向截面上的应变线性分布系数作为衡量的标准。结果表明，绝大部分截面的线性分布系数均接近于1，证明了岔管整体工作性态良好以及本观测系统已经达到很高的精度。研究发现。线性分布系数是混凝土“微裂缝”发展程度的有效指示器，为今后进一步研究洞室衬砌应力增加了一条新的途径。

Stress Analysis for Reinforced Concrete Bifurcated Pipes in the Yellow River Diversion Project

The cause of high stresses in the reinforced concrete bifurcated pipes is analyzed. It is recognized that the low temperature and strong restraint of the surrounding rock is the most important factor. A simple way is found out to resolve the stress into water stress and thermal stress on the basis of the finding that there is a very short period in which the water level is raised but the temperature of the pipe is not be changed. A linear distribution parameter of strain is put forward as a standard to show whether the pipe is under a good elastic condition. It is shown that most of the coefficients of linear distribution are close to 1. This fact proves that the bifurcated pipe is under a good condition, and the observation system is of high accuracy. It is found that this parameter is a valid indicator to show the degree of development of micro cracks in the concrete. This is a new way to research into the stress in the lining of chambers.