Tunnels. A "Tunnel" shall be defined as a subterranean excavation, lined or unlined, which because of its length necessitates an employee or employees working underground for a distance of ten (10) feet or more. On all work classified as "Tunnel," the tunnel classification and rates shall apply to the entire length of the tunnel, from portal to portal. A tunnel whose horizontal grade is over thirty percent (30%) and less than sixty percent (60%) shall be defined as a "Raise." A tunnel whose horizontal grade is greater than sixty percent (60%), and whose depth is more than twice its largest horizontal dimension, shall be defined as a "Shaft." The above definitions of work shall apply also to the work of timbering and lining of tunnels (raises and shafts) as described above.
Tunnels. While there are a collection of specific guidelines or requirements regarding fire protection, ventilation, etc., there are no formal national design codes or construction standards that include seismic provisions for tunnels in Canada. Consequently, various accepted references for checking loads on a tunnel due to earthquake ground motions are generally used.
Tunnels. Transverse and longitudinal strain may be measured using a fiber optic sensor network. This can be done at many point locations on the ceiling of the tunnel, as well as, on sidewalls. Because fiber sensors can have both very long or very short gauge lengths ranging from millimeters to kilometers, the designer has a wide choice of strain sensing options to deploy for an appropriate health monitoring system. Figure 1.3 shows a fiber optic sensor system deployed to measure strain distribution in a tunnel. Other possible uses for fiber optic sensors in tunnels would be to measure critical points of corrosion on rebar and other reinforcing structures. System of Embedded Fiber Optic Strain SensorsTunnel Supports Figure 1.3: System of strain sensors to monitor condition of tunnels
Tunnels. All bores/tunnels for mainline installation shall be staked at the start and end of the bore/tunnel. Points shall be set direct (horizontally) and oﬀset a distance that will not be disturbed during construction (horizontal and vertical) with iron and witness lath.
Tunnels. The vertical clearance for tunnels shall be at least 4.9 m except where as alternative routing providing the 4.9 m is available. For those lesser situations, at least 4.3 m plus an allowance for resurfacing may be provided. The desirable width for tunnels is at least 13.3 m. This width consists of two 3.6 m lanes, a 3.0 m right shoulder, a 1.5 m left shoulder, and a 0.8 m safety walk on each side. However, because of the high cost, a reduced tunnel width can be accepted, but it must be at least 9.1 m wide, including at least a 0.5 m safety walk on each side.
Tunnels. Historically, the Union as the sole representative of the employees covered under this Agreement, has acquired and maintained an expanded craft jurisdiction in the construction of new tunnels or in the repair, rehabilitation or modification of existing tunnels. The work in tunnels to be performed by employees covered under this agreement is as follows but not limited to: All work for all tunneling operations, including but not limited to subways, railroads, sewer, water, vehicular and utility tunnels and all shafts, manholes and access ways in connection therewith, all work in connection with but not limited to, the excavation, dewatering, shor- ing, forming, the pouring, placing and finishing of con- crete and grout and the reinforcing of same by any means, the bolting and securing of any structural support system, the handling and installation of all pre-cast products, the loading, unloading and handling of all materials, the changing and sharpening of all bits, heads and cutters, the operation of hoists, road headers, air tuggers and hydrau- lic jacking systems, the installation of temporary wiring, all signaling, caulking, mining, the operation of drilling machines, drilling and blasting, the laying of all pipe and conduit and other work. The broader scope of the tun- nel jurisdiction covered under this Agreement is further identified in the tunnel classifications as stated under Ar- ticle 18 of this Agreement, whether in compressed air or free air or by soil solidification methods or otherwise in rock or in soft ground and whether driven by liner plate, by shield, by mole or otherwise. Such operations are here- inafter collectively referred to as “the trade”. The employer recognizes that the Union has acquired jurisdiction of the tunnel work described above and agrees that it will not assist or abet vio- lations of such acquired jurisdiction in the hiring of TERRITORIAL JURISDICTION employees or in the continuation of employment of employees performing such work. Any work jurisdiction now exercised by Heavy and General Laborers’ Locals 472 and 172 of the Laborers’ International Union of North America shall be recognized by the Utility and Transportation Con- tractors Association and the Associated Construction Contractors of New Jersey.
Tunnels. The tightening of Israel’s closure of the Gaza Strip in 2007 led to a flourishing of trade through tunnels that had been dug under the Gaza-Egypt border. The easing of the closure in mid-2010 brought a change in the types of goods that are transferred via the tunnels. In addition to contraband and weapons, the tunnels are now used mainly for the transfer of fuel and basic construction materials such as gravel, cement and steel, whose import via Kerem Shalom is subject to restrictions. As a result of turmoil in Egypt, in June and July of 2013, activity in most of the tunnels was obstructed.