围岩超前支护与“岩土变形控制分析工法”

Discussion on Advance Support and ADECO-RS Approach

从现代隧道工程的理念出发,为最大限度地获益于地层的自承能力,软弱岩体中隧道工程的关键在于控制围岩的变形。开挖后及时施作"系统支护",是控制围岩变形的主要措施。此外,对掌子面前方未开挖岩土体的"超前支护"可以遏制其"预变形"Pietro Lunardi提出的"岩土变形控制分析工法"(ADECO-RS Aapproach)强调对"超前核心体"的约束,推荐在掌子面设置纵向锚杆。这种工法在防范围岩坍塌和优化工法方面的效果已在实际工程中得以体现。为了更准确和深入地理解该工法的实质,本文着重对"超前核心体"控制围岩变形的作用进行探讨,以求对超前支护的机理有进一步理解,避免过分强调或夸大其功能,以便在实际工程的设计和施工中正确地运用,达到规避风险和优化工法的目的。

From the view of modern tunnel engineering philosophy and for the purpose of making the maximum use of self-bearing capability of the ground,controlling deformation of surrounding rocks is the key in weak rock tunnelling.The system support installed immediately after excavation is the main measure to control the rock deformation.In addition,the pre-support of the advance core ahead of the tunnel face is useful to control the pre-convergence.ADECO-RS Approach,which is devised and developed by Pietro Lunardi,suggests using fiber glass structural elements for pre-confinement of the advance core.In terms of preventing rock collapse and optimizing the construction approach,the approach has been verified in some tunnel projects.However,in order to deeply understand the inherent nature of the ADECO-RS Approach and the mechanism of the advance support,the effect of advance core reinforcement on the deformation control will be mainly discussed in this paper.The goal of the analysis and discussion is to properly apply the advance support in design and construction of tunnels,to avoid overemphasis and exaggeration of its function,to mitgate construction risks and optimize the construction approach.