地下工程约束混凝土支护理论与技术研究进展

Research progress of confined concrete support theory and technology for underground engineering

随着我国地下工程的迅速发展,建设规模不断扩大,工程建设过程中面临大量高应力、极软岩、强采动和断层破碎带等复杂条件,导致围岩变形严重、控制困难,联合支护是复杂条件围岩有效控制的必然选择。工程实践表明,拱架作为联合支护的最后一道防线,其承载能力不足导致冒顶、塌方等事故频发。约束混凝土支护具有承载能力高、塑性韧性好、经济性能优等特点,近年来在矿山工程与隧道工程等领域得到了广泛应用。众多学者在室内试验、理论研究、设计方法、现场施工等方面进行了系统研究。在室内试验方面,进行了约束混凝土基本构件与拱架的力学性能试验研究,为约束混凝土拱架承载力计算理论与设计方法提供了依据。在理论研究方面,建立了拱架内力计算模型,形成了约束混凝土支护强度计算理论。在设计方法方面,进行了约束混凝土拱架整体选型设计、核心混凝土设计、灌注口与排气口设计、节点设计以及拱架间距与纵向连接设计研究。在现场施工方面,形成了矿山巷道复合施工与交通隧道机械施工两大类工法,研发了成套关键技术与装备。对上述研究内容进行了总结,同时对下一步约束混凝土体系设计、施工与验收规范制定以及在交通、水利、市政等不同工程领域的推广应用方面进行了展望。

With the rapid development of underground engineering in China and the continuous expansion of construction scale,a large number of complex conditions are faced in the construction process such as high stress,extremely soft rock,strong mining and fault fracture zone,which lead to serious surrounding rock deformation and control difficulties.The engineering practice shows that,combined support is the inevitable choice to control surrounding rock effectively under complex conditions.As the last line of defense for combined support,the lack of bearing capacity of arch leads to frequent roof fall and collapse.Confined concrete(CC)support has the characteristics of high bearing capacity,good plasticity and toughness,and excellent economic performance.In recent years,it has been widely used in mine roadways and traffic tunnels.Many researchers have done a lot of research in laboratory test,theoretical research,design method and field construction.In the aspect of indoor test,a large number of mechanical properties tests of CC arches and basic components are carried out,which provide the basis for the bearing capacity calculation theory and design method of CC arch.In the aspect of theoretical research,the calculation model of internal force of arch is established,and the calculation and design method of CC support strength is formed by combining the compressive bending strength criteria of CC components.In terms of design method,the overall selection design,concrete core design,grouting hole and exhaust hole design,joint design,arch spacing and longitudinal connection design are studied.In the aspect of field construction,two kinds of construction methods,mine roadway composite construction and traffic tunnel mechanized construction,have been formed,and a set of key technologies and equipment have been developed.This paper summarizes the above research contents,and prospects the design,construction and acceptance criterion formulation of confined concrete system in different engineering fields in the next step.At the same time,the future developments of design,construction and acceptance standard of confined concrete system and its application in different engineering fields such as traffic,water conservancy and municipal engineering are prospected.