Ground-beds vertical

These are very commonly used for the impressed current system. A typical vertical anode installation is shown in Fig. 5.27. This type of ground-bed has a low resistivity which is an outstanding advantage. Almost all of the current flow is from the anode to the backfill by direct contact so the consumption of the material is mostly at the edge of the backfill. Vertical anodes are installed with a carbonaceous backfill. 

These are used because of the near presence of (c) Deep Vertical Anodes the other structures and also because of the limitations of the soil depth. A typical installation is A deep ground-bed is defined as a ground-bed shown in Fig. 5.28. The anodes should always be in which the anodes are installed vertically in a placed in moist soil or in hygroscopic backfill so drilled hole at a depth of 50 ft or more. A typi-that it does not dry out during the dry season. cal deep anode installation is shown in Fig. 5.29. 

The above procedure can be used to determine the anode to earth resistance. Design charts can be constructed for vertical anodes and horizontal anode ground-beds for both impressed and galvanic anode systems. The development of design curves is discussed in Section 5.31.2. 

One or more anodes installed vertically at a nominal depth of 15 m (50 ft) or more below the earth s surface in a drilled hole for the purpose of supplying cathodic protection for an underground or submerged metallic structure. See also ground bed. 

Fig. 9-3 Grounding resistance of anodes in a continuous coke bed with a covering of earth t = 1 m and a diameter d = 0.3 m for a specific soil resistivity of p = 10 Q m. Horizontal anodes from Eq. (24-23), see line 9 in Table 24-1 vertical anodes R ...

The wattage is directly proportional to the grounding resistance of the whole anode bed and therefore to the specific soil resistivity. Equation (9-5) gives the grounding resistance of the anode installation which either consists of n horizontal or vertical single anodes or of anodes with a horizontal continuous coke bed of total length I = ns. The total cost function is given by [1] ... 

In the first reconstruction [27] of road slabs contaminated with CL, silicon iron anodes were embedded in a layer of coke breeze as shown in Fig. 19-4a or the current connection was achieved with noble metal wires in a conducting mineral bedding material. Slots were ground into the concrete surface for this purpose at spacings of about 0.3 m (see Fig. 19-4b). This system is not suitable for vertical structures. 

From initial deposition and burial under overlying sedimentary materials through succeeding geological periods, coal beds are continually subject to the action of ground water. Thus, some coal beds have developed a system of essentially vertical fractures—thin cracks, often filled with coatings of pyrite. calcile. kaolinite and other minerals deposited from ground water. Impurities from these veins lower the quality of the coal. 

It is assumed that the water surface displacement created by the earthquake is identical to the vertical displacement of sea bed induced by the ground motion. 

The settlement hose is a flexible hose, which is installed underneath the landfill at the initial ground or bed level. The hose, which is filled with water, follows the deformation of the subsoil under the weight of the landfill. A pressure meter is inserted into the hose, which measures the water pressure at fixed intervals. The water pressure gives accurate information on the vertical depth of the probe relative to the water level at both ends of the flexible hose. The measurements are used to establish a longitudinal depth profile. 

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