Introduction of Conventional Tunneling cutting-edge technologies
The Cutting-Edge Approach
More than 100 years of Obayashi’s engagement in tunnel construction, 50 years since the indispensable NATM (New Austrian Tunneling Method) was introduced in Japan ---- over those years, tunnel technology has improved dramatically. With the experience of more than 600 projects around the world, Obayashi is committed to technical research and development, combining our predecessors’ expertise with the latest technologies.
(Available only in Japanese.)
Exploration Technology
Non-core drilling geological exploration ahead of the tunnel faceTunnel Navi®
Prevents collapse and deformation by predicting the geology ahead of the tunnel face. Exploration costs can be reduced by 90%.
Geological prediction ahead of the tunnel face using hydraulic down-the-hole hammerHigh-speed non-core drilling geological exploration ahead of the tunnel face
Quick geological exploration 150m ahead of the tunnel face.
Prediction and countermeasures for water inflow in tunnelsSystem for water inflow detection ahead of tunnel face and countermeasure selection
Detects fracture and aquifer zones and selects drainage measures to prevent sudden water.
Prediction ahead of tunnel faceDetection of water inflow zone by elastic wave exploration
Prevents collapse by predicting large and sudden water inflow. Minimizes interruptions to excavation work.
Evaluation of heavy metals in tunnelsHeavy metal evaluation with cuttings of non-core drilling
Quickly collects samples for heavy metal and evaluates them in a short time.
Observing the inside of a boreholeSimple intra-hole observation camera
A simple and inexpensive way to observe the inside of a borehole.
Tunneling Technology
Continuous belt conveyor system with quick extensionALCS®
For rapid tunnel construction without interrupting the excavation work.
Boring technologyBubble Drilling System
Use of air bubbles to prevent deterioration of the ground and lower costs.
Ground preloading methodContact Bag Method®
Prevents subsidence caused by tunnel excavation with cloth bags filled with ultra-rapid setting mortar.
Ground stabilization methodFooting reinforcement using stepped steel pipes
Increases the bearing capacity of the tunnel footing and prevents subsidence.
Stability measures for tunnel faceTough Tube®
Cost-effective tunnel face reinforcement using high strength steel pipe anchorage.
Quick reinforcement of the tunnel faceLightweight AGF (All Ground Fastening method) steel pipe
Improves work efficiency with lightweight high-strength steel pipes for rock reinforcement.
Lining Technology
Middle-fluidity lining concrete for tunnel liningSmooth-Crete
For high quality tunnel lining with high-flowing concrete.
Concrete lining for tunnelsNeuro-Crete Neo®
High-flow and self-compacting properties without increasing cementitious contents.
Concrete lining for tunnelsHigh-compactable concrete
High quality and economical tunnel lining concrete.
Equipment for tunnel liningTelescopic-type traveling formwork with continuous belt conveyer passing through the inside
Improves tunnel lining quality by lengthening the curing time while allowing concurrent tunnel excavation and lining.
Equipment for tunnel liningRail-mounted mobile formwork vibrator
For high quality, economical tunnel lining.
High-performance curing system for tunnel liningMoist-Cure®
Constructs high-quality and highly durable tunnels by preventing cracks during concrete lining curing.
Waterproofing system for tunnelsAutomatic extension system for long, wall shape-following waterproof membranes
Follows the unevenness of the tunnel wall surface for high quality construction.
Automatic lining concrete placing systemContinuous placing system with an automatic telescoping delivery hose
Reduces labor and improves quality of the lining operation.
Environmental technology
Dust reduction methodTravel Clean Curtain®
For quick and dramatic improvement of the work environment in the tunnel.
Noise reduction technology for tunnel blastingBlast Silencer®
Hybrid blasting sound countermeasure technology for low-frequency sounds and audible sounds, utilizing the resonance phenomenon and the sound absorption effect.
Measurement Technology
Measurement of settlement ahead of tunnel facePreceding displacement meter
Prevents collapses by predicting face instability in advance.
Ground displacement measurementThree-axis ground displacement gauge
Monitors the effects of tunnel faces passing through nearby structures.
Measurement of tunnel invert heavingInvert Displacement Gauge®
Measures heaving in the tunnel invert and allows for corrective measures.
Tunnel Face Collapse Detection SystemRockfall Finder®.
Detects early signs of face collapse.
Information management technology using 3D modelsCIM (Construction Information
Modeling/Management)
Improves productivity and maintenance management by visualizing the construction process and streamlining the integrated information.
Renovation
Concrete surface protection and reinforcement methodSmooth Board Method®
Reinforces the surface of the tunnel lining with cement boards.
Spray-on repair and reinforcement methodJOT’S-Crete®
Quick, economical repair and reinforcement with fiber-reinforced mortar spray.
Back-fill grouting methodSpace Pack Method®
Fills the void behind the tunnel lining with plastic injection material.
