ASCE Manual of Practice No. 118 For Belowground Pipeline Networks For Utility Cables

U-Tech: Underground Technology Cutting Edge Technical Information for Utility Construction and Rehabilitation
By Dr. Lawrence M. Slavin, Dr. Oleh Kinash, Dr. Mohammad Najafi | January 2010 Vol. 65 No. 1
Figure 2 Typical Underground Conduit Construction (Courtesy of Underground Devices, Inc.)

In particular, the manual provides details regarding the two installations in Arlington, TX, within property controlled by the University of Texas at Arlington (UTA). In this case, the BCN networks were installed within the grassy strips, adjacent to sidewalks, on Mitchell Street and on South Davis Drive, intersecting streets within the campus. The objective was to provide UTA with a convenient network for the future installation of communications cables to serve local university facilities.

Due to the anticipated surface damage, and potentially large restoration expenses, it was decided that trenchless methods should be considered for installing the BCN along both streets. This construction procedure therefore differs from that implied in the description of the BCN in which it is assumed that an open trench would be available to conveniently place the various cables and BCN conduits and handholes. Nonetheless, such an environment (established community or area) is frequently encountered and it is important to verify that the BCN could, in fact, be deployed in such an application.

Mini-HDD equipment was utilized to cost-effectively place two 4-inch field-fused PVC conduits, along both routes. Although there were several challenges in utilizing a mini-HDD rig to simultaneously pullback the two conduits, as well as to properly interface with the total of six handholes, the installations were successfully and efficiently accomplished. Figure 9 shows the conduits at one of the handhole locations, prior to placement of the handhole itself. Figure 10 shows a completed installation. Additional details are provided in MOP No. 118.

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Figure 9 Overlapping Conduits from Adjacent Pullbacks

Although the UTA trials did not include the placement of any direct-buried cables, any initially required utility cables, or preferably small ducts for their later containment, may be installed simultaneously alongside the two BDN conduits during the mini-HDD pullback operation, or possibly placed within one of the latter BDN ducts.

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Figure 10 Installed Handhole (With and Without Cover), Mitchell Street