Tunneling

VIP-Heinke has unrivalled expertise in seal design and elastomer technology, and is one of the world’s leading manufacturers of elastomer gaskets for the segmental lining of tunnels, commonly known as tunnel segment gaskets (TSGs). 

 

TSGs, which are located in precast grooves encircling the mating faces of each segment, give a secure rubber-to-rubber waterproof seal as soon as the segments are bolted together. The low compression set and stress relaxation values of the elastomeric compound used in their manufacture enable elastomeric TSGs to recover under reduced applied load thereby maintaining a positive seals between segments despite ground movements. 

 

VIP-Heinke manufacture a range of TSGs designed for precast concrete, steel and cast iron segments used in the lining of tunnels or shafts and large mains sewers. All are precision engineered to meet the precise requirements of individual projects. 

 

Elastomeric TSGs provide an economic and effective solution for sealing tunnels and shafts against water ingress. Compared to other sealing methods, elastomeric TSG's offer many benefits.

DSI's selection of underground supports, the widest in the world, affords the contractor, the designer, and the owner a matchless combination of high performance and tunneling at low cost.

One of these products alone - liner plates - offers these outstanding advantages:

• Economy of construction in time, excavation, material, manpower.

• Maximum support per given length with minimum weight of steel.

• Standard variation of plate design for all shapes of tunnels in dry or wet ground.

• Predictable strength, fire resistant.

• Continuous support during the critical mining phase in soft ground tunneling.

• Easy to store, handle and erect, whether the tunnel is straight, curved, circular, elliptical or horseshoe in shape.

• Gasket plates that seal joints, stop water leakage and reduce air loss when water is a problem.

 

Steel liner plates provide a relatively light-weight, easy-to-handle, safe support for soft ground tunneling because the ground that supplies the loading also supplies the resistance to the load. The liner plate assembly simply distributes and transmits the load to the surrounding earth. As a steel liner plate ring takes load vertically, it tends to deflect inward at the top and outward at the sides. The ground resists deflection of the lining by developing a passive force equal in magnitude and opposite in direction to the force exerted by that of the lining. The diagram on the left illustrates this principle. 

 

The ability of the surrounding ground to resist the outward bulge of the liner plate ring is the key to vertical load support. With the ring confined to a small amount of deflection, the thrust line induced by the load is forced to follow the ring of liner plates. Thus, the ability of the assembly to withstand the applied load depends upon its ability to transmit ring thrust from plate to plate around the ring. Obviously, this ability is enhanced by the four-flange design of DSI's plates.

Liner Plates
 

There are various methods for determining the required strength of tunnel linings. Nevertheless, the type of ground, the location and depth of cover, the size and length of the tunnel, level of ground water, superimposed loading, and history always guide these calculations. 

 

DSI liner plates can be purchased in 16" and 24" widths as corrugated or smooth plates. Liner plates are formed from one piece of metal to provide longitudinal and circumferential flanges. The plates can be galvanized and/or bituminously coated and grout holes with plugs can be included. For special conditions gasketed liner plates and tapered liner plates can also be manufactured. Liner plates can be installed alone or in conjunction with steel ribs if additional support is required.

System Description

DSI was a pioneer in the development of rock and soil anchor systems and technology for the Tunneling and Mining Industry. Today DSI is a world leader in this field with an outstanding reputation of product quality and customer service. The double corrosion protected THREADBAR® anchor is universally recognized as the "standard" for anchor performance and corrosion protection. DSI is dedicated to the advancement of the "State-of the Art" for rock anchors ready to support you during the design, planning and construction of your project. When questions arise, contact your nearest DSI representative.
 

DSI offers a complete line of THREADBAR® designed for both temporary or permanent use, manufactured from materials best suited to meet the needs of your project.

DYWIDAG Rock Anchors are generally used to:	THREADBAR® Anchors
• Anchor external forces and uplift forces • Anchor retaining walls • Stabilize eccentrically loaded foundations, slopes, • rock walls and cuts • Stabilize underground excavations and mines • Increase the stability of dams	are available in 1" (26 mm), 1-1/4" (32 mm) and 1-3/8" (36 mm) nominal diameter, in lengths up to 60 feet (18.3 m) without couplers, with a guaranteed minimum ultimate tensile stress of 150 or 160 ksi (1034 or 1103 MPa).

Special steels for high impact, seismic and low temperature applications can be made available on special order.

Prestressed rock and soil anchors have become an important tool for the Tunneling engineer. Their safe and reliable use in both permanent and temporary applications is accepted throughout the world.

 

Rock Anchors are post-tensioned bars installed in drilled holes for which at least the entire bond length is located in rock. The anchor force is transmitted to the rock by bond between the grout body and the rock. Rock anchors can remain unbonded in the free stressing length allowing the anchor to be checked and retensioned at any time. In such cases, adequate corrosion protection for the stressing anchorage and the free stressing length must be provided. On the other hand, the free stressing length can also be fully grouted after the anchor has been stressed, in which case force adjustment is no longer possible.