期刊名称：International Journal of Advances in Engineering and Management
电子版ISSN：2395-5252
出版年度：2021
卷号：3
期号：6
页码：794-803
DOI：10.35629/5252-0306672676
语种：English
出版社：IJAEM JOURNAL
摘要：Based on the load calculation method of shallow buried tunnel in the current highway tunnel design specification, the calculation formula of surrounding rock pressure of unsymmetric small clear distance tunnel is derived, and the variation of surrounding rock pressure under the influence of the thickness of middle rock wall and the internal friction angle of soil is further analyzed. The results show that the excavation of the back tunnel will lead to the bias-pressure phenomenon of the surrounding rock pressure of the tunnel; the horizontal lateral pressure of the inner side of the tunnel is less than that of the outer side of the tunnel, while the vertical pressure of the vault of the inner side of the tunnel is larger than that of the outer side of the tunnel;with the increase of the thickness of the middle rock wall, the vertical pressure bias ratio of the vault decreases, and the horizontal lateral pressure increases;with the increase of the friction angle in the soil, the vertical pressure bias ratio of the vault first increases and then decreases; when the internal friction angle , the bias ratio reaches the maximum; the horizontal lateral pressure increases with the increase of the friction angle of the soil, and generally changes with the influence parameters. The bias ratio tends to be 1; the bias is related to the geometric parameters of successive tunnels, so that the larger the geometric parameters of the tunnel, the closer the bias ratio tends to be 1; for unsymmetric tunnels with short net distance, the overall bias ratio is closer to 1 when the preceding tunnel is large; in other words, when the excavation width of the preceding tunnel is larger than that of the posterior tunnel, it is more conducive to the load distribution and stability of the tunnel structure, and if the excavation width of the preceding tunnel is larger, it is more conducive to the load distribution and stability of the surrounding rock of the tunnel.
关键词：unsymmetric;short net distance tunnel;surrounding rock pressure;bias ratio
