Innovation in Tunnel Design & Construction

This category recognises projects that are driving use of innovative methods and smart technologies within the industry to improve the design or delivery of tunnelling work. The work could reduce risk to the programme, cost or stakeholders during design or delivery or help create a better outcome for the client over the lifespan of the asset..

Barhale and Thames Water
Innovation in offline solution

A sinkhole appeared at Rye Meads Sewage Treatment Works (STW) on the 1675mm diameter Stevenage Trunk Sewer immediately before it entered the works. The sewer is around 6.7m, laid in gravel beds with high ground water levels and adjacent to a SSSI. Reparative works were needed to reduce the risk of further collapse. The original online proposal was to remediate by relining a 125m section of the sewer from downstream of the penstock chamber to the pumping station. It would have required expensive, extended overpumping and presented risk while the fragile existing pipe was prepared for relining. Barhale proposed an alternative offline solution to remediate the full length of the Stevenage trunk sewer. This solution provides a 50% longer design life and reduces the risk of flooding – paramount for the adjacent SSSI.

China State Construction Engineering, Hong Kong
Box Jacking Tunnelling Method Under MTRC Airport Express Lane

Hong Kong International Airport is developing a Three-runway System (3RS), which includes the construction of a new Automated People Mover (APM) and Baggage Handling System (BHS) are underway on the existing Airport Island. A critical section crosses under the operational Airport Express Line (AEL) and was constructed using Jack Box tunnelling techniques. Two 30m long portions of the APM and BHS tunnels were jacked as continuous precast reinforced concrete boxes under the AEL within a ground improved grout block. A horizontal pipe pile canopy positioned above the tunnels was constructed using micro TBM methods to allow ground movement control and and enhance face stability. The two boxes were jacked forward on jacking slab using hydraulic jacks positioned at the rear of the boxes. An additional innovative strand jacking system was employed in combination with the canopy piles as an anti-drag system supplemented the jacking slab thrust force.

Civil Engineering and Development Department, Hong Kong SAR, Hyder-Meinhardt Joint Venture and Hong Kong Productivity Council
Autonomous Air-ground Cooperative Tunnel Inspector (AAGCTI)

The innovation “Autonomous Air-ground Cooperative Tunnel Inspector” (AAGCTI) is an intelligent and autonomous tunnel inspection system that revolutionizes precise inspection work particularly in GPS-denied environments. Five most notable features include high-precision inspection outcome, 360-degree full inspection coverage through UAV and UGV cooperation, accurate real-time positioning of the robots and images taken even in the GPS-denied environments, air-ground robotic cooperation enabling a lighter UAV to sustain longer inspection times, and edge-computing technologies for instantaneous AI defect detection with fully-digitalised and comprehensive reports. The innovation is developed and being fully deployed in the Trunk Road T2 project in Hong Kong, which comprises 2.4 km of subsea twin tunnels constructed by TBMs underneath Victoria Harbour. It has achieved over 98% defect identification accuracy, inspection speeds 23 times faster than conventionally, and 50% savings in inspection costs, with construction safety significantly enhanced. The synergy between AAGCTI and digitalisation greatly enhances project and asset management.

Dragados
SOGUN: Geometric Control System for Shotcreting and other tunnelling works

The SOGUN system represents a significant advancement in the execution cycle of the shotcrete in tunnels. SOGUN is a compact unit whose functionality is automated in a process that scans the tunnel in 3D, generating a surface point cloud. This data is then compared to the pre-loaded theoretical tunnel surface, and an image is projected on the tunnel wall, indicating areas and amount of excess or missing concrete thickness. This process is completed in under a minute, far quicker than the traditional spray painting method, which typically takes between one and a half to three hours, requires at least two people, a man lift, and a dedicated total station. Shotcrete robot operators clearly understand the work to be performed. SOGUN enhances productivity, reduces costs, and minimizes workers' risks, introducing superior quality finishes and safety. Additionally, it promotes sustainability by optimizing material usage and reducing waste, leading to lower environmental footprint.

Mott MacDonald
ParaRanger - An innovative digital tool for ground parametric analysis

ParaRanger, developed by Mott MacDonald Ltd, is a cutting-edge digital tool specifically crafted to optimize temporary tunnel support systems through ground parametric analysis. It seamlessly integrates available commercial software with programming logic for ground engineering optioneering, showcasing its formidable capabilities. Moreover, its user-friendly interface negates the need for extensive training, making it incredibly accessible. ParaRanger not only resolves various ground engineering issues but also actively promotes digital culture in engineering and facilitates future integration of artificial intelligence. It skilfully achieves a harmonious equilibrium between safety and sustainability in temporary tunnel support designs, marking a groundbreaking advancement in tunnelling and poised to revolutionise the industry with its highly refined solutions.

Mott MacDonald
SpeedBot – A tool for rapid tunnel lining structural modelling

This digital tool, SpeedBot, represents a highly advance approach to the structural analysis process for tunnel linings. Employing contemporary digital methodologies, such as Computational Design, streamlines the creation of complex analytical tunnel models, significantly reducing the time spent on concrete lining modelling. This allows designers to focus more deeply on analysing input and output for multiple alternative options, fostering sophisticated thinking and exploring a wide range of optimization possibilities, including sustainability goals. Furthermore, SpeedBot enables the structural lining analysis of a greater number of locations along the tunnel alignment, preventing over-generalisation in the design process. It consistently delivers sustainable solutions for tunnelling challenges, solidifying its role as an invaluable asset in embracing digital evolution. Leveraging advanced technologies and methodologies, the future of engineering is poised to surpass expectations for sustainability.

Skanska Costain Strabag Joint Venture
Innovative Cross Passage Construction Using Sprayed Concrete and Ground Freezing Between Two HS2 TBM Driven Tunnels

The Western Section of the 8km HS2 tunnel drive has mixed face conditions which makes tunnelling challenging.13 of the 20 Cross Passages require full freeze rings to deal with the potential for unravelling sands and the water ingress.The ability of SCL to bind to frozen ground has long been a topic of discussion and until now a matrix of immediate practical methods was not available. The prescription of further temporary works such as mesh or dowels only further increase face exposure times which could potentially exacerbate fall outs. The tunnelling team have provided innovative solution options to suit the stage of excavation which reduce the potential for SCL fallouts increasing the safety of excavating in frozen ground.The solutions include the optimization of lining thicknesses, advance sequencing /lengths, SCL application and mix design. The tunnelling team have also created a new benchmark for the definition of exclusion zones in frozen ground.