Tunnelling and Ground Engineering

Tunnelling and Underground Spaces

Tunnels transform rail and networks by allowing transport through dense urban cities without affecting the landscape above. Water and wastewater tunnels bring us modern hygiene and sanitation standards with workings discretely hidden underground. Utility tunnels power electricity, gas, telephone and the internet, making modern living possible.
At Ayesa, our tunnelling capabilities are combined with our broad pool of expertise to add value to the numerous infrastructure projects we help deliver. Award-winning and with a respected reputation, Ayesa integrates tunnel design and ground engineering to bring benefits to clients' projects. Whether a tunnel is large or small, there will be numerous varying challenges such as ground and soil type, length and depth, presence of seismic activity and water. Our tunnelling expertise has been used in rail, metro, light rapid transit, road, motorways, highways, water and wastewater, stormwater and utility tunnels.

Tunnelling is applied to numerous applications:

• Predicting and monitoring tunnelling-induced ground movement to help protect against structural damage
• Assessing and designing ground improvements
• Numerical modelling of soil/structure interaction and groundwater/excess flows
• Using computerised geotechnics and developing cut-and-cover tunnel techniques for construction
• Ground engineering and geotechnics

Our tunnelling capability brings expertise and understanding to our client's projects from concept to final delivery, across a wide variety of tunnelling techniques and capabilities:

• Bored tunnels in hard rock or soft ground
• Tunnel boring machines
• Segmental lining, sprayed concrete lining (SCL or NATM)
• Drill and blast tunnel excavation
• cut-and-cover tunnels
• Immersed tubes
• Trenchless methods
• Micro-tunnelling, pipejacking and directional drilling
• Shaft sinking in soft ground
• Rock and tunnel refurbishment of tunnels.

Tunnelling techniques such as the cut and cover is often most found in underground metro stations.  In respect of soft ground tunnelling, TBMs (tunnel boring machines) with sprayed concrete lining (SCL) to segmental linings is one of a variety of techniques used by Ayesa.  Our design teams use the latest technologies, including numerical modelling of the ground/structure interaction, creating optimum schematics, rectifying problems and addressing uncertainties that once onsite can cause delays and extra costs for our clients.  Today, our clients include national utilities such as Irish Water, where we are helping to upgrade the existing sewer network in Blanchardstown in an 88 million euros project.  Our team designed the 30m deep underground storage tanks (with a total capacity of approximately 30,000m³) and the 3.2km diameter pipeline. The pipeline is being installed using trenchless tunnelling techniques which has less impact and disturbance than open-cut methods, with minimal impact and disturbance to the sensitive urban environment, which includes the M50 motorway and a public park.