Monitoring of Underground Construction Processes

地下建筑越来越多地被用于提供基础设施解决方案，例如隧道、竖井和深挖，特别是在城市和其他敏感环境中。地下建设过程通常在方案和成本方面受到严格限制，然而，有一些不确定因素限制了这些因素的控制准确性。其中最重要的领域之一是结构与地面的相互作用，特别是周围土壤对结构施加的接触应力。过大的摩擦接触应力的发展会对隧道掘进和沉井井沉陷等过程产生重大影响。在设计期间预测或计算土-结构接触应力的能力仍然相对较差，并且在施工之前对地面条件的了解可能有限。因此，在施工过程中能够准确监测土-结构相互作用是很有必要的。为了实现这一目标，需要用合适的监测系统对地下建设项目进行监测。地下环境对传统仪器（如电传感器）提出了许多挑战。许多测量量的幅度变化非常小，这意味着需要高分辨率的传感器。此外，监测系统经常受到严重的电磁干扰，需要在恶劣的条件下运行。这项工作的主要目的是在施工过程中更好地了解土与结构之间的界面。这项研究将通过开发先进的智能系统来监测土壤-结构相互作用，努力展示对当前监测能力的改进。希望这可以被利用来积极地告知施工过程，从而提高效率和安全性。这项研究还将扩展当前在实际项目中安装仪器的经验。这有助于解决一些技术和后勤方面的挑战，包括安装、数据采集和提供实时反馈。此外，从已开发的系统中获得的信息应该为改进未来项目的设计提供重要的范围。这可能包括验证设计假设，为优化未来设计和降低设计风险提供机会。本研究的方法学将寻求新的技术，以促进准确测量土-结构法向和摩擦接触应力。新型换能器将采用光纤传感技术，即光纤布拉格光栅（fbg）。光纤系统和fbg克服了使用传统仪器时面临的一些问题，包括抗电磁干扰和恶劣环境下的耐用性。虽然这些技术以前已经应用于力传感器，但它们主要局限于机器人控制和微创手术等行业。在设计、建造、校准和测试新的换能器之前，将对这些应用进行审查。然后，这些将集成到智能、自动化的地下监控系统中，用于现场施工项目。增加更复杂的接触应力信息将有助于这些系统在施工过程中提供更详细的反馈和预测。传感器的光纤特性也将有助于提高系统的鲁棒性和可靠性。目前EPSRC在地面工程领域的战略包括解决复杂的SSI问题，以防止关键基础设施的故障，以及将智能技术集成到工业中。因此，这项研究完全符合这些目标。

Underground construction is being increasingly adopted to provide infrastructure solutions, such as tunnels, shafts and deep excavations, particularly in urban and other sensitive environments. Underground construction processes are often tightly constrained in terms of both programme and cost, however there are several uncertainties that limit how accurately these factors can be controlled. One of the most important areas is the structural interaction with the ground, in particular the contact stresses exerted on structures by the surrounding soil. The development of excessive frictional contact stresses can have a major impact on processes such as tunnelling and caisson shaft sinking. The ability to predict or calculate soil-structure contact stresses during design is still relatively poor and the understanding of ground conditions prior to construction can be limited. As a result, it is desirable to have the ability to accurately monitor soil-structure interaction during construction. To achieve this, it is required to instrument underground construction projects with suitable monitoring systems. The underground environment presents a number of challenges to traditional instrumentation, such as electrical sensors. Many of the measured quantities undergo very small variations in magnitude, meaning sensors with a high resolution are required. Furthermore, monitoring systems are often subject to significant electromagnetic interference and are required to operate in harsh conditions.The key aim of this work is to provide better understanding of the interface between the soil and structure during construction. This research will endeavour to demonstrate an improvement on current monitoring capabilities, by developing advanced, intelligent systems to monitor soil-structure interaction. It is hoped that this can be exploited to actively inform the construction processes, leading to improvements in both efficiency and safety. This research will also extend current experience of installing instrumentation on live projects. This can help to address some of the technical and logistical challenges, including installation, data acquisition and providing real-time feedback. Furthermore, information obtained from the developed systems should offer significant scope to improve the design on future projects. This could include validating design assumptions, leading to opportunities for optimising future designs and reducing design risks.The methodology for this research will seek to pursue novel technologies to facilitate accurate measurement of the soil-structure normal and frictional contact stresses. New transducers will be developed using fibre optic sensing technology, namely fibre Bragg gratings (FBGs). Optical fibre systems and FBGs overcome some of the issues faced when using traditional instrumentation, including immunity to electromagnetic interference and durability in harsh environments. Whilst these technologies have been applied to force sensors previously, they have mainly been confined to industries such as robotic control and minimally invasive surgery. A review of these applications will be undertaken, before designing, building, calibrating and testing the new transducers. These will then be integrated into intelligent, automated underground monitoring systems, for deployment onto live construction projects. The addition of more sophisticated contact stress information will help these systems to provide more detailed feedback and predictions during the construction process. The fibre optic nature of the sensors will also help to improve the robustness and dependability of the systems.Current EPSRC strategies for the area Ground Engineering include addressing complex SSI to prevent failure of critical infrastructure as well as integrating intelligent technologies into industry. This research is therefore completely aligned with these targets.