Underground excavation designs in mining and civil engineering projects are associated with a different geometric, complex ground structure, field–stresses, and groundwater conditions. Due to diverse influence factors and various requirements for each project, the design procedure should be customised based on the site-specific factors. The design procedure is only a direct and triggering process, while in a complex ground condition, mixed failure mechanisms may occur. The objective of this research is to present a new methodology "Comprehensive Underground Excavation Design" called CUED method with emphasis on diagnosis of ground behaviour and failure mechanism(s) in deep and hard rock conditions for long-term life expectations. The CUED method proposed in six steps including ground characterisation, diagnosis of ground behaviour, identifying failure mechanism, design analysis to manage ground behaviour, construction, field measurements/monitoring and design update. A procedure has been defined for each step by determination of input data, processing data and output data, so-called IPO approach. IPO is applied to determine parameters of the CUED method in each step. Based on the proposed method, rock mass composition provides sufficient information to the diagnosis of ground behaviour. Then, different types of failure modes and related mechanisms are evaluated following three main factors: rock mass structures, stress concentration and construction conditions/key features of the projects. In some cases, only one failure mechanism is dominant, but in many cases, may failure starts with one mechanism and then followed by other mechanism or combination of mechanisms. It makes the design more complicated and should be adjusted during operational stages. Design analysis to manage ground behaviour is carried out to determine appropriate strategy in an unstable ground such as selecting suitable excavation method, excavation sequences, and ground stabilisation methods regarding time-cost model of the projects. Meanwhile, the design parameters are implemented in the construction stage by excavation, loosening, depressurisation/stress management, quality control of materials and installing ground support systems. Optimisation of design parameters is performed through new acquired data in field measurements to reduce the risk of rock failures. The proposed design procedure was verified through several case studies from mining and underground excavation projects, and some typical cases were presented. The purpose of the proposed design method is to attempt to increase productivity, cost optimisation, safety improvement, and consequently diminish instability in underground excavations. The research results indicated that the proposed method efficiently increase safety and optimise the project's cost and time. The presented CUED method could be used as engineering tools for underground excavation design.

采矿和土木工程项目中的地下开挖设计与不同的几何形状，复杂的地面结构，场应力和地下水条件相关。由于每个项目的影响因素和要求各不相同，因此应根据特定地点的因素定制设计程序。设计过程只是一个直接的触发过程，而在复杂的地面条件下，可能会发生混合故障机制。本研究的目的是提出一种称为“ CUED法”的新方法“综合地下开挖设计”，重点在于对深部和坚硬岩石条件下的地面行为和破坏机理进行诊断，以实现长期预期寿命。CUED方法分六个步骤提出，包括地面表征，地面行为诊断，识别故障机制，管理地面行为的设计分析，施工，现场测量/监控以及设计更新。通过确定输入数据，处理数据和输出数据为每个步骤定义了一种过程，即所谓的IPO方法。在每个步骤中，都会应用IPO来确定CUED方法的参数。基于提出的方法，岩体成分为地面行为的诊断提供了足够的信息。然后，根据以下三个主要因素评估不同类型的破坏模式和相关机制：岩体结构，应力集中和施工条件/项目的关键特征。在某些情况下，只有一种故障机制占主导地位，但在许多情况下，故障可能始于一种机制，然后是其他机制或机制组合。它使设计更加复杂，应在操作阶段进行调整。进行管理地面行为的设计分析，以确定不稳定地面中的适当策略，例如选择适当的开挖方法，有关工程的时间成本模型的开挖顺序和地面稳定方法。同时，在施工阶段通过开挖，松动，降压/应力管理，材料质量控制和安装地面支撑系统来实施设计参数。通过在现场测量中获取新数据来优化设计参数，以降低岩石破裂的风险。通过采矿和地下挖掘项目的若干案例研究验证了所提出的设计程序，并提出了一些典型案例。提出的设计方法的目的是试图提高生产率，优化成本，提高安全性，从而减少地下基坑的不稳定性。研究结果表明，该方法有效地提高了安全性，并优化了项目的成本和时间。提出的CUED方法可作为地下挖掘设计的工程工具。