作者：徐平；张敏霞；崔杰

第一作者单位：河南理工大学土木工程学院

摘要：为实现沉陷土体中管周土内部的变形可视化,设计了透明沉陷土体中的管-土变形可视化试验系统,并开展了相应试验研究。以玻璃砂作为固体颗粒材料,以正十二烷和十五号白油质量比为1:3.5的孔隙液合成试验用透明土,制作了由透明土箱、砂箱和底座3部分组成的模型箱,采用漏砂控制实现了土体沉陷。试验中利用激光照射透明土形成散斑场切面,通过CCD数字相机连续获取沉陷过程中的切面图像,采用PIV技术对土体变形前后的散斑场切面进行分析,得到了沉陷过程中管周土体的完整位移场。试验系统实现了沉陷过程中的管-土变形的可视化,得到了管周土体的完整位移场;管道顶部2～3倍管径内形成了明显的土拱现象,管道上部土体在沉陷过程中产生了向管道两侧“绕流”的现象,管道下侧土体存在较大的下沉位移并逐渐与管道脱离,管道失去下部土体支撑,导致管道挠曲变形增加,附加应力急增。本文研制的可视化试验系统为研究沉陷影响下的管-土相互作用机理提供了新的研究方法,为地下结构与土相互作用模型试验研究提供了新思路。

Abstract：In order to realize visualization for the internal deformation of pipeline surrounding soil during the process of subsidence,a visualization test system was designed and tested based on the transparent soil.Transparent soil was composed by glass sand,twelve alkane and No.15 white mineral oil mixture (1:3.5).The model box was composed by transparent soil,sand box and the base of test box.The sand leakage method was adopted to complete the soil subsidence.Speckle field of sections were formed by the laser irradiation in the test.CCD camera was used to capture a sequence of images,and then PIV was used to analyze these images of speckle field.The displacement field was acquired during the soil subsidence process.The system realized the visualization of pipeline soil deformation and got the displacement field.The soil arching phenomena occured 2~3 times diameter of the pipe on the top of pipeline and soil on the top of pipe flowed around the pipe.The deformation of soil under the pipeline was increased and soil support was lost under the pipeline.The flexure deformation and additional stress increased rapidly.The visualization test system provides a new research method and idea to study the mechanization for pipeline soil interaction induced by subsidence and experimental study for underground structure soil interaction.

基金：国家自然科学基金项目(51504081,51508166)；国家自然基金-河南省人才联合基金资助项目(U1404527)；河南省科技攻关项目(162102210221)；河南省高校基本科研业务费专项(NSFRF140147)；

关键词：透明土;沉陷土体;散斑场;可视化;

DOI：10.16186/j.cnki.1673-9787.2018.01.019

分类号：TU43;TU990.3