摘要
作为衡量土力学特性的关键指标,相对密实度也是划分围岩等级的重要指标,其对隧道掘进时地层沉降和应力的影响十分重大。基于北京工业大学自主开发的盾构隧道掘进模型试验平台,通过开展不同相对密实度土层中隧道的掘进试验,系统测量地表和地层中的沉降和隧道周边的应力。试验结果表明:随着相对密实度的增大,地表和地层中沉降槽的形状由高斯函数分布形变为三角形,深度和宽度均越来越小;掘进过程中地表沉降的出现更加滞后;拱顶和拱肩处的应力路径变得越来越陡,使土体出现明显的剪胀,从而导致地层沉降槽的形状发生上述变化。因此,在模拟隧道掘进时,应考虑不同相对密实度土层的剪胀性,才能合理地预测地表的沉降。
As a key index to judge the mechanical properties of soil,the relative density is also an important index for the classification of surrounding rock grades.It is of great significance to study the influence on stratum subsidence and stress during tunnelling.Based on the model test platform for shield tunnels developed by Beijing University of Technology,tunnelling tests were conducted in soil with different relative densities,the surface or stratum subsidence and stress during tunnelling were measured systematically.The test results showed that:with the increase of relative densities,the shapes of subsidence troughs for the stratum changed from the distribution shape of Gaussian Function to the triangular shape,the depth and width were smaller and smaller;the subsidence of the surface lagged more behind the process of being tunnelled;the stress paths at the arch crown and arch shoulder became steeper and steeper,that caused the obvious dilation in soils and brought about the above change laws in the shape of the the stratum subsidence troughs.Therefore,in simulations of tunnelling,it was necessary to consider the dilatancy of soil to ensure the rational predications on surface subsidence.
作者
阿卜杜拉-穆塔里伯·凯特玛斯
田雨
路德春
杜修力
Abdul Motalleb QAYTMAS;TIAN Yu;LU Dechun;DU Xiuli(Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China)
出处
《工业建筑》
CSCD
北大核心
2021年第7期11-17,共7页
Industrial Construction
基金
北京市自然科学基金项目(8204055)
国家自然科学基金项目(51908010)。
