考虑非均匀地基原水管道受力特征模型试验研究

为了解决上海市长江引水三期非均匀地基区间管道爆管问题，采用缩尺试验研究非均匀地基条件下原水管道受力变形特征，针对非均匀地基的密实度和长度进行逐级划分，并设计不同的试验工况研究管道的受力特征。结果表明:管道下方非均匀地基的密实度对管道所受应力有较大影响，即密实度越高，应力值越低，管底处的应力受密实度和非均匀地基长度的影响最大。非均匀地基区域边缘处截面应力与管道中央截面应力相比，非均匀地基长度为1D时，截面Ⅰ上测点的应力值与截面Ⅱ的应力值大小相近，而在1.5D和2D长度条件下，呈现出截面Ⅰ的应力值高于截面Ⅱ的规律。研究成果对非均匀地基区域的原水管道运营维护具有重要的指导作用。

Model test study on mechanical characteristics of raw water pipeline considering non uniform foundation

In order to solve the problem of interval pipeline bursting on the non uniform foundation in the third phase of the Yangtze River diversion in Shanghai,the scale model tests were conducted to study the mechanical and deformation characteristics of the raw water pipeline considering the condition of non uniform foundation.The compactness and length of the non uniform foundation were divided step by step,then different test conditions were designed to study the mechanical characteristics of the pipeline.The results showed that the compactness of the non uniform foundation under the pipeline had a great influence on the stress of the pipeline,that is,the higher the compactness,the lower the stress value,and the influence of the compactness and length of the non uniform foundation on the stress at the pipeline bottom was the greatest.The stress at the edge section of the non uniform foundation area was compared with the stress at the central section of pipeline,when the length of the non uniform foundation was adopted as 1D,the stress values of the section Ⅰ were close to those of the section Ⅱ,however,the stress values of section Ⅰ were bigger than those of section Ⅱ under the length conditions of 1.5D and 2D.The research results play an important role in guiding the operation and maintenance of raw water pipeline in the non uniform foundation area.