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| Research on tunnel pressure arch based on coupled discrete and continuous method |
| Received:April 27, 2019 Revised:August 12, 2019 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7511/jslx20190427001 |
| KeyWord:discrete-continuous coupling model tunnel pressure arch tunnel burial depth equivalent area of stress concentration of tunnel pressure arch path of force PFC2D |
| Author | Institution |
| 高峰 |
重庆交通大学 土木工程学院, 重庆 |
| 谭绪凯 |
重庆交通大学 土木工程学院, 重庆 |
| 陈晓宇 |
中机中联工程有限公司, 重庆 |
| 丁其乐 |
林同棪国际工程咨询中国有限公司, 重庆 |
| 李星 |
重庆交通大学 土木工程学院, 重庆 |
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| Abstract: |
| The pressure arch of a tunnel is a key problem in tunnel engineering.There is a lack of microscopic study of tunnel pressure arch characteristics as a continuous by a numerical simulation method.The discrete element method which is good at microscopic study requires a large computer storage space and a long calculation time.The discrete-continuous coupling model through the transmission of force is built based on the existing model.Calculation methods of mean stress,calculation area of mean stress and traversal particle method of coupling procedure are researched.The stress characteristics of surrounding rocks after tunnel excavation,the formation mechanism of a tunnel pressure arch and the tunnel pressure arch characteristics are studied based on the self-developed and optimized discrete-continuous coupling model.The equivalent area of stress concentration of a tunnel pressure arch generated by tunnel excavation is calculated under different buried depths of 10 m,14 m,18 m,22 m,26 m,30 m,34 m,which reveals the variation law of a tunnel pressure arch with tunnel burieddepth.The results show that,the self-developed and optimized discrete-continuous coupling model can not only ensure the calculation accuracy,but also give a full play to the advantages of discrete element method in microscopic study.Layered pressure rings appear near the excavation face after tunnel excavation,and the indirect contact force between the layered pressure rings of vault and invert bottom reduces,the bearing capacity of surrounding rock decreases.The equivalent area of stress concentration of a tunnel pressure arch is decreasing with the increase of tunnel buried depth,and the bearing capacity of a tunnel pressure arch is increasing.However,a tunnel pressure arch is stabile when the tunnel depth reaches a certain limit. |
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