城市地下穿越工程的新理論與新技術

錢七虎

(陸軍工程大學爆炸沖擊防災減災國家重點試驗室，中國工程院院士)

隨著現代地下空間利用的發展，城市地下工程建設正面臨越來越多的地下穿越工程，如: 下穿樓房、下穿鐵道等附加應力較大且變形控制越來越嚴格的重要建筑物工程;也有諸如附加應力小、變形控制不嚴，但江水壓力大容易造成螺旋輸送機發生土塞突涌或盾構機上浮等險情的下穿河流項目。無論哪種地下穿越工程，一旦發生事故，不僅影響工程自身的建設，還會對被穿越結構或環境產生巨大的影響。所以，每項地下穿越工程的施工都會如履薄冰，必須格外謹慎。周順華教授新近出版的《地鐵盾構法隧道下穿工程》，提出了“以控制開挖應力釋放(書中提法)來控制施工變形”的新理論，為地下開挖工程的微變形設計提供了理論基礎，同時也為施工控制技術找到了一種新途徑。周順華教授將地下穿越施工變形分為絕對量控制和相控制，并給了具體的控制方法;同時指出，變形控制的難易程度取決于地層的工程和力學性質，并給出了特定地層條件下盾構機型和配置的選擇;在此基礎上，又提出了施工參數同盾構機型、土層和隧道線型之間的相互影響關系。這些新穎的觀點，涉及個性化變形指標設計思想、變形協調控制方法，以及地下穿越工程的輔助措施設計等內容。書中還提供了依據其新理論設計的下穿高速鐵路、下穿普速鐵路和鐵路樞紐的案例;同時，首次系統闡述了土壓平衡盾構下穿大型江河湖泊時的抗上浮、螺旋輸送機防突涌和防高壓江水的技術要點。誠如《地鐵盾構法隧道下穿工程》所言:“盾構法隧道下穿工程是一項系統工程，影響因素眾多。工程人員只有熟知原理，及時掌握施工現場的動態，才能因時、因勢采取針對措施，使施工按照預想的軌跡進行。”相信周順華教授提出的系統性理論和創新技術，必將對大幅提升我國地下穿越工程的技術水平發揮重要作用。

commentary

New Theory and Technology of Urban Underground Crossing Engineering

QIAN Qihu

(State Key Laboratory of Disaster Prevention & Mitigation of Explosion & Impact，Army Engineering University of PLA，An academician of the Chinese Academy of Engineering)

With the development of modern underground space utilization，urban underground engineering constructions are facing more and more underground crossing engineering． For example，some important building projects whose additional stress is larger and whose deformation control is getting more and more stringent，such as underground crossing buildings，underground crossing railways and etc． There are also such underground crossing river projects whose additional stress is small and whose deformation control is not strict，however，whose high river-water pressure is easy to cause the spiral conveyor to come about such dangerous cases as the earth plug's being abrupt gush or the shield machine's floating up． No matter what kind of underground crossing engineering，once an accident occurs，not only would project constructions themselves be affected，but also the structures or environment that are passed through underground would be made a huge impact． Therefore，every construction of underground crossing projects will be like walking on the thin ice，and extra caution must be paid to． "Metro Shield Method Tunneling Underground Crossing Engineering" that Professor Zhou Shunhua newly published puts forward a new theory of " controlling construction deformation by controlling excavation stress release" ( the formulation of this book) ，providing theoretical basis for micro-deformation design of underground excavation engineering，and at the same time，also finding a new way for construction control technology． Professor Zhou Shunhua divides the underground crossing construction deformation into absolute quantity control and relative quantity control，and introduces the concrete control methods． Meanwhile，he points out that the difficult or easy degrees of deformation control depend on stratum' s engineering and mechanical properties，and gives the choice and configuration of shield models under specific stratum conditions． Then，on this basis，he suggests again the interaction relations between construction parameters and shield models，soil layers andtunnel line-types．

These novel viewpoints involve the contents of the design idea of individualized deformation index, the method of deformation coordination control and the auxiliary measures design of underground crossing engineering, etc. In this book, the cases of underground crossing high-speed railways, underground crossing normal-speed railways and railway hubs that are designed according to his new theory are also provided. Meanwhile, the technique keynotes of anti-floating of earth-pressure balance shield′s underground crossing large rivers and lakes, preventing abrupt gush of the spiral conveyer and defending high-pressure river water are systematically elaborated for the first time.

Just as "Metro Shield Method Tunneling Underground Crossing Engineering" says: "Shield method tunneling underground crossing engineering is a systematic project, and there are many impact factors for them." Engineering personnel only well know the principles, timely grasp the dynamics of the construction site, and then they can take counter-measures according to time and situations, so as to make the construction carry on in accordance with the expected trajectory." It is believed that the systematic theory and innovation technique that Professor Zhou Shunhua puts forward in this book will play an important role in greatly improving the technical level of underground crossing engineering in our country.