城市地下穿越工程的新理论与新技术

钱七虎

(陆军工程大学爆炸冲击防灾减灾国家重点试验室，中国工程院院士)

随着现代地下空间利用的发展，城市地下工程建设正面临越来越多的地下穿越工程，如: 下穿楼房、下穿铁道等附加应力较大且变形控制越来越严格的重要建筑物工程;也有诸如附加应力小、变形控制不严，但江水压力大容易造成螺旋输送机发生土塞突涌或盾构机上浮等险情的下穿河流项目。无论哪种地下穿越工程，一旦发生事故，不仅影响工程自身的建设，还会对被穿越结构或环境产生巨大的影响。所以，每项地下穿越工程的施工都会如履薄冰，必须格外谨慎。周顺华教授新近出版的《地铁盾构法隧道下穿工程》，提出了“以控制开挖应力释放(书中提法)来控制施工变形”的新理论，为地下开挖工程的微变形设计提供了理论基础，同时也为施工控制技术找到了一种新途径。周顺华教授将地下穿越施工变形分为绝对量控制和相控制，并给了具体的控制方法;同时指出，变形控制的难易程度取决于地层的工程和力学性质，并给出了特定地层条件下盾构机型和配置的选择;在此基础上，又提出了施工参数同盾构机型、土层和隧道线型之间的相互影响关系。这些新颖的观点，涉及个性化变形指标设计思想、变形协调控制方法，以及地下穿越工程的辅助措施设计等内容。书中还提供了依据其新理论设计的下穿高速铁路、下穿普速铁路和铁路枢纽的案例;同时，首次系统阐述了土压平衡盾构下穿大型江河湖泊时的抗上浮、螺旋输送机防突涌和防高压江水的技术要点。诚如《地铁盾构法隧道下穿工程》所言:“盾构法隧道下穿工程是一项系统工程，影响因素众多。工程人员只有熟知原理，及时掌握施工现场的动态，才能因时、因势采取针对措施，使施工按照预想的轨迹进行。”相信周顺华教授提出的系统性理论和创新技术，必将对大幅提升我国地下穿越工程的技术水平发挥重要作用。

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.