Helmut Wannenmacher

RWTH Aachen University

Grouting is a key element in hydropower construction, as it enhances the long-term stability of a conduit. Grouting for pressure tunnels and shafts can be grouped into rock mass and structural grouting operations. Structural grouting refers to either contact grouting focused on a structural enhancement of the cast concrete lining or to more complex...

The Niagara Tunnel Project (NTP) is a 10.1 km long water-diversion tunnel in Niagara Falls, Ontario, which was excavated by a 7.2 m radius tunnel boring machine. Approximately half the tunnel length was excavated through the Queenston Formation, which locally is a shale to mudstone. Typical overbreak depths ranged between 2 and 4 m with a maximum o...

In the common view of tunnelling experience, discontinuities as joints and fractures are considered with downscaling effects on the mechanical properties of rock mass. The effect of discontinuities in mechanized hard rock excavation is of ambivalent nature. The presence of favourable number and orientation of joints leads in general to a reduced ef...

The Niagara Tunnel Facility Project in Ontario, Canada, is one of the most outstanding hydropower projects recently completed. The pressure tunnel with a nominal internal diameter of 12’800 mm is constructed with a final unreinforced concrete lining of 600 mm. The long-term stability of the lining is ensured with a passive pre-stressed concrete lin...

The recently completed Niagara Tunnel Facility Project in the province of Ontario in Canada is an extension of the Sir Adam Beck hydropower station originally built in the 19th century. The project includes the construction of a diversion tunnel to supply the existing hydropower station with an additional 500 m3 of water per second. The long-term s...

One of the remaining tackles in grouting is the postulation of appropriate grouting parameters for an economical execution of works. A minimized usage of material to achieve a good grade of sealing or consolidation is desired. The lack of comprehensible parameters is the driving factor for either too conservative execution or opposite false outcome...

Pre-excavation grouting is essential for mitigating groundwater inflow to unlined tunnel structures. Prevention of initial water inflow proved best practices to balance groundwater conditions throughout the utilisation of the tunnel. The grouted rock mass acts as a circumferential sealing barrier instead of a secondary lining to minimise groundwate...

The Semmering Base Tunnel (SBT), which has a total length of 27.3 km, is one of the most important construction projects in the Baltic‐Adriatic railway corridor. The base tunnel crosses the foothills of the Eastern Alps and connects the two federal states of Lower Austria and Styria. Due to the complex rock conditions, extensive and novel grouting...

The Semmering Base Tunnel (SBT), with a total length of 27.3 km, is one of the leading construction projects of the Baltic-Adriatic Railway Network. The tunnel connects the two federal provinces of Lower Austria and Styria and cuts through the eastern part of the Alps. The construction lot SBT 1.1-Tunnel Gloggnitz is characterized by a complex geol...

Tunnels are significant in shaping our future infrastructure. Increasing limitations of the available ground require underground solutions for future infrastructure projects. Due to various reasons, boundary conditions for project realization are becoming more and more substantial, and the parties involved have to tackle a wide range of stakeholder...

Tunnelling conditions characterized by large and long-term deformations demand yielding support elements as a part of the shotcrete lining. The yielding support elements transform radial displacements into a tangential closure without compromising the lining system's support capacity and avoiding micro-cracking and overstressing of the shotcrete du...

Cement-based or chemical grouting materials are the foremost choice to seal water-bearing areas in subsoil or rock efficiently. Anti-wash out resistant cement-based grout mixes and water-reactive grouting materials based on polyurethane are the preferred material for pre-ex- cavation grouting. However, adequate equipment and material technology now...

Grouting of rock and soil evolved over the past decades as a unique niche within the construction industry and gained very high technical standard regarding the grouting equipment, steering and even latest integration within the BIM system. Recent developments went along with the establishment of new grouting criteria, which predict grout spread in...

Currently a lot of caverns are constructed in Switzerland which will utilize underground space for multiple purposes. Two different caverns, a shallow situated one hosting the production of waferfabs, and a deep seated one for a hydroelectric project, will be used to highlight the application of different computational methods. The application of c...

Der zentrale Zugang des Baulos SBT 3.1 des Semmering Basistunnels erfolgt mittels zweier paralleler Schächte im Talbereich der Mürztalquerung. Der Schacht Sommerau 2 mit einem lichten Durchmesser von 8,0 m und einer Teufe von rd. 100,0 m ist ein redundanter Versorgungsschacht im Nahbereich des Hauptzugangsschachtes mit einem lichten Durchmesser von...

Zementbasierte Suspensionen zählen zu den am häufigsten eingesetzten Injektionsmitteln. Dem Anwender steht dabei eine Vielzahl an unterschiedlichen Bindemitteln und Zusätzen zur Verfügung. Die Auswahl und Zusammenstellung einer geeigneten Mischung für die Ausführung erfolgt in der Regel anhand projektspezifischer Vorgaben und Randbedingungen. Dabei...

Grouting works have become a key essential part of temporary and permanent works in the fields of tunnelling and complex demanding construction projects, mainly in the forefront of construction to sufficiently prepare weak ground to meet the prerequisites for construction. Grouting measures are hereby often carried out as a specific measure with th...

The type of excavation and the lining concept and related possibilities for the grouting works affects the successful and economic excavation of small pressure tunnels within water bearing ground. Especially, shielded TBMs with segmental lining are hereby facing severe challenges in sealing heavy water ingress, due to the constraints of access to t...

Hydropower plants are of great relevance for European energy production. Vertical shafts in comparison to inclined shafts may serve as a cost effective alternative in case of favourable project conditions. Vertical shafts have a higher ground cover compared to surface parallel inclined shafts. The increased rock mass cover and therefore higher in-s...

The sustainable allocation of an economical lining type highly depends on a reasonable utilisation of the ground conditions, the geological and hydraulic conditions as well as the bedding of the lining. Especially the hydro-geological conditions govern the utilization of permeable and watertight lining systems. A flow chart based on geomechanical...

The recently completed Niagara Tunnel Facility Project in the province of Ontario in Canada is an extension of the Sir Adam Beck hydropower station originally built in the 19th century. The project includes the construction of a diversion tunnel to supply the existing hydropower station with an additional 500 m3 of water per second. The long-term s...

The extension of Grimsel 3 hydropower project (600 MW) entails the construction of a 2.5 km long tailrace tunnel, a machine and a transformer cavern as well as a new 600 m deep vertical shaft connecting the existing conduit with the Räterichsboden reservoir. Generally high in-situ stress conditions are expected for the construction of the extension...

Brittle failure of rock mass is a widespread phenomena especially known for massive and hard rock mass as encountered. The Niagara Tunnel Project gives a special opportunity to study the insight of brittle failure especially for laminated claystones. Rock mass behaviour is highly influenced by the high horizontal stress regime. The history of the h...

Hydropower plants are of great relevance for European energy production. Inclined or vertical shafts serve as a cost alternative to inclined steel-lined shafts in case of favourable ground conditions. Vertical shafts have a higher ground coverage compared to inclined shafts oriented parallel to the surface. The increased ground coverage and the res...

In populated alpine regions, infrastructure projects often compete with nature and the general public for open space or other natural resources. The Waferfab project located near Sargans, Switzerland, is a ground- breaking infrastructure project using underground space as a manufacturing facility for sensitive industrial processes which requires st...

Worldwide the continuously on-going upgrade of infrastructure requires many subsurface constructions for rail or highway tunnels, hydro-electric power plants, fresh water tunnels etc. Many of excavated tunnel meters are driven by tunnel boring machines (TBMs) because of the cost effectiveness. But problems may occur due to sudden and unexpected cha...

Hydropower plants are of great relevance for European energy production. Inclined or vertical shafts serve as a cost alternative to inclined steel-lined shafts in case of favourable ground conditions. Vertical shafts have a higher ground coverage compared to inclined shafts oriented parallel to the surface. The increased ground coverage and the res...

TBM tunnelling technique has improved significantly over the last decades and is gaining continuous market presence. Switzerland has a lot of experience with large TBM projects. The various projects have taught us several lessons which led to a continuous development of TBMs. A risk based geotechnical design is highly recommended for a successful t...

Currently a lot of caverns are constructed in Switzerland which will utilize underground space for multiple purposes. Two different caverns, a shallow situated one hosting the production of waferfabs, and a deep seated one for a hydroelectric project, will be used to highlight the application of different computational methods. The application of c...

The Niagara Tunnel Facility Project in Ontario, Canada, is one of the most outstanding hydropower projects currently under construction. The pressure tunnel with a nominal internal diameter of 12.8 m is constructed with a final unreinforced concrete lining (minimum thickness 500 mm). The long-term stability of the lining is ensured by a passive pre...

Die Beeinflussung durch Gebirgsparameter führt im Hartgestein immer wieder zu Abweichungen der TBM-Penetrations-Prognose gegenüber den tatsächlich erreichten Penetrationen. In diesem Beitrag wird dies anhand eines TBM-Vortriebes im kristallinen Hartgestein exemplarisch aufgezeigt. Die im Weiteren aufgeführten Beobachtungen und Erkenntnisse wurden i...

The Niagara Tunnel Facility Project, in Ontario, Canada is one of the most outstanding hydropower projects currently under construction. The pressure tunnel with a nominal internal diameter of 12800 mm is constructed with a final unreinforced concrete lining of 600 mm. The long term stability of the lining is ensured with a passive prestressed conc...

Hydropower plants are of great relevance for European energy production. Vertical shafts in comparison to inclined shafts may serve as a cost alternative in case of favourable ground conditions. Vertical shafts have a higher ground coverage compared to surface parallel inclined shafts. The increased rock mass cover and therefore higher in-situ stre...

Numerische Berechnungsverfahren gehören heutzutage als wesentlicher Bestandteil zur Planung von untertägigen Anlagen. Die Zuverlässigkeit dieser Methoden hängt allerdings von einer Reihe von Faktoren und ab, deren Bestimmung und Berücksichtigung in der Modellierung einen bestimmenden Einfluss auf das Ergebnis haben. Dazu zählt einerseits die Wahl d...

Grouting as an effort to consolidate and seal the rock mass before excavation or subsequently after excavation has become a mayor requirement and demand in modern tunneling. Grouting techniques have improved constantly with the raised demands of various tunnel projects in complex geological situations. Pre-excavation and post grouting techniques ha...

The Tehran Shomal Motorway project is one the major infrastructure projects currently ongoing in Iran. The line will connect the capital of Iran, Tehran with the Caspian Sea. The traffic volume is very high and the conditions of the actual roads, especially in the winter and holiday times are dangerous. The Alborz tunnel system, with the actual ong...

Kops II is a 450 MW parallel scheme of the existing HPPKops I ofthe Vorarlberger IIIwerke AG in Austria. The Kops II pressurised headrace tunnel "Versalstollen II" comprises an inner diameter of 4.9 m and a length of about 5 500 m. The 4 780 m long TBM portion of the tunnel was excavated with a DS-TBM through gneiss and schist formations and is lin...

Kops II is a 450 MW parallel scheme of the existing HPP-Kops I of the Vorarlberger Illworke AG in Austria. The Kops II pressurised headrace tunnel "Versalstollen II" comprises an inner diameter of 4.9 m and a length of about 5 500 m. The 4 780 m long TBM portion of the tunnel was excavated with a DS-TBM through gneiss and schist formations and is l...