施俊1，贾坚1,2

（1 同济大学地下建筑与工程系， 上海 200092；

 2 同济大学建筑设计研究院(集团)有限公司， 上海 200092）

［摘要］盾构在掘进的过程中，设定合理的支护力是确保隧道开挖面前方土体稳定的关键。利用二维离散元方法，本文研究了动荷载作用下在干砂地层中盾构开挖的合理支护力。首先，通过动荷载作用下隧道开挖面卸荷模型研究卸荷位移S、地层扰动大小与开挖面支护力的关系；其次，通过动荷载作用下盾构掘进模型研究开挖面支护力与地层损失的定量关系，最终从强度控制、地层扰动控制、开挖面地层损失控制三种不同角度对盾构掘进中开挖面所需支护力的大小进行了分析比较，得出基于开挖面地层损失控制的支护压力比最大，为0.99~1.07。并将结果与静载下进行对比，验证动荷载下的盾构施工控制要求更加严格。

［关键词］动荷载； 离散元； 支护力； 开挖面地层损失率； 砂土

中图分类号： U455.43 文献标识码： A文章编号： 1002-848X(2015)S2-0058-07

*上海市科学技术委员会科研计划项目（14231200700）。

作者简介：施俊，硕士研究生，Email:shijun0220@126.com。 

Analysis of support pressure for shield tunneling by discrete element method under dynamic load

Shi Jun1, Jia Jian1,2

(1 Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China;

2 Tongji Architectural Design (Group) Co., Ltd., Shanghai 200092, China)

Abstract: The key point of guarantee the stability of the soil in front of the tunnel excavation face is to set reasonable support pressure in the process of shield advancing． Support pressure in dry sand induced by unloading in tunnel face under dynamic load based on two-dimensional discrete element method (DEM) was analyzed. Firstly, the relationship of the workface support pressure between the unloading displacement (S) and ground disturbance quantity was analyzed by means of tunnel excavation unloading model under dynamic load. Secondly, the quantitative relationship between the tunnel face support levels and ground volume loss ratio was also analyzed by means of shield driving model under dynamic load. Finally conclude that the required supporting pressure ratio is 0.99~1.07 for ground volume loss ratio at tunnel face control as a result of comparison and analysis of workface support pressure requirements obtained from three different standards including strength failure control, ground disturbance control and ground volume loss ratio at tunnel face control. It is verified that the construction control requirement under dynamic load is stricter than that under static load by comparison of the results under static load.

Keywords: dynamic load; discrete element method; support pressure; ground volume loss ratio at tunnel face; dry sand