The impact of shallow cover on tunnelling in soft soil

On the face support of microtunnelling TBMs

Face stability of microtunnelling TBMs is an important aspect for a safe and controlled project execution. Lack of proper face support can lead to sudden collapse with resulting large settlements. Guidelines for minimal and maximal support pressures in most codes do not take the infiltration of bentonite suspension in coarser soils into account....

On the effects of the TBM-shield body articulation on tunnelling in soft soil

When a Tunnel Boring Machine (TBM) is driven in soft soil, the TBM-shield constantly interacts with the surrounding soil profile excavated by the cutting wheel. The interaction pattern of shield-soil interface displacements determines compression and extension sectors in the surrounding soil. Soil compression is generated when the shield...

Tunnelling in Soft Soil: Tunnel Boring Machine Operation and Soil Response

Constructing tunnels in soft soil with the use of Tunnel Boring Machines may induce settlements including soil movements ahead of the face, soil relaxation into the tail void, possible heave due to grouting, long lasting consolidation processes, and potentially several other mechanisms. A considerable amount of the total soil displacements seems...

Criteria for face support of microtunneling TBMs

Face stability of microtunnelling TBMs is an important aspect for a safe and controlled project execution. Lack of proper face support can lead to sudden collapse with resulting large settlements. Guidelines for minimal and maximal support pressures in most codes do not take the infiltration of bentonite suspension in coarser soils into account....

Electrical resistivity method for the measurement of density changes near a probe

Urban Problems - Underground Solutions

Detectie van afwijkingen in diepwandvoegen

In Nederland werden diepwanden beschouwd als een veilige en bewezen technologie voor de kerende constructie van een diepe ontgraving. Door de grote lekkages die zich in de metro bouwprojecten in Amsterdam en Rotterdam voordeden, is de perceptie van het risicoprofiel van de diepwand veranderd.

Tunnel-boring in soft soil: A study on the driving forces applied to a slurry-shield TBM

Tunnel-boring in soft soil: A study on the driving forces applied to a slurry-shield TBM

Report on Underground Solutions for Urban Problems

World wide, we see developing nations building new infrastructure as well as developed cities rehabilitating and expanding their infrastructure to meet the demands of increased population, energy efficiency, and environmental awareness of the public. Ten years ago ITA issued its special edition of the Tribune entitled “Why Go Underground,...

Detecting defects in diaphragm walls prior to excavation

Recent incidents with leaking diaphragm walls during construction of subway lines in Amsterdam and Rotterdam (Netherlands) have led to reconsideration of the diaphragm wall as a retaining wall construction for deep excavations. In our opinion the joints between the panels are the weak spot. During concrete pouring the concrete should replace the...