- 摘 要
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施俊1，賈堅1,2
（1 同濟大學地下建筑與工程系， 上海 200092；
2 同濟大學建筑設計研究院(集團)有限公司， 上海 200092）
［摘要］盾構在掘進的過程中，設定合理的支護力是確保隧道開挖面前方土體穩(wěn)定的關鍵。利用二維離散元方法，本文研究了動荷載作用下在干砂地層中盾構開挖的合理支護力。首先，通過動荷載作用下隧道開挖面卸荷模型研究卸荷位移S、地層擾動大小與開挖面支護力的關系；其次，通過動荷載作用下盾構掘進模型研究開挖面支護力與地層損失的定量關系，最終從強度控制、地層擾動控制、開挖面地層損失控制三種不同角度對盾構掘進中開挖面所需支護力的大小進行了分析比較，得出基于開挖面地層損失控制的支護壓力比最大，為0.99~1.07。并將結果與靜載下進行對比，驗證動荷載下的盾構施工控制要求更加嚴格。
［關鍵詞］動荷載； 離散元； 支護力； 開挖面地層損失率； 砂土
中圖分類號： U455.43 文獻標識碼： A文章編號： 1002-848X(2015)S2-0058-07
*上海市科學技術委員會科研計劃項目（14231200700）。
作者簡介：施俊，碩士研究生，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
