JP6366340B2 - Tunnel interior board with tiles attached to a steel plate substrate - Google Patents

Description

  The present invention relates to a tunnel interior board in which tiles are attached to a steel plate substrate, and more specifically, tile panels in which porcelain tiles are attached to one side of a substrate with an adhesive are arranged vertically and horizontally so as to be along the tunnel wall surface. Further, the present invention relates to a tunnel interior board that uses the reflection function of the glossy surface of the tile to assist lighting in the tunnel.

  The installation form of the tunnel interior plate is, for example, as shown in FIG. 6, and the tile panel 3 in which the reflective function of the glossy surface and the highly washable tile 1 is stuck on the substrate 2 in the vertical and horizontal arrangements is adopted. It is becoming. At the work site in the tunnel, rather than directly bonding individual tiles to the wall surface, a large number of tiles can be handled together like the tile panel 3 shown in FIGS. Reduce. In addition, since a large number of tiles are stuck to the substrate in the panel factory, it is possible to reduce the time required for arranging the tiles and increase the precision of the sticking dimensions, and in addition, the tunnel wall surface can be easily homogenized.

  The tiles are, for example, 10 cm long and 20 cm wide, and are adhered to the substrate 2 having a size of about 100 cm × 150 cm with an adhesive leaving the joints 12 of about 4 mm in the vertical and horizontal directions. Such tile panels 3 are fixed to the wall surface in two or three steps in the vertical direction as shown in FIG. 6, and are continuously arranged parallel to the roadway. The fixing to the wall surface is performed by driving the concrete anchor 8 through the substrate 2 from the joint 9 on the roadway side (see also FIG. 7) and driving it into the wall 4, or a metal fitting 11 (see FIG. 8) and supporting the tile panel 3 and preventing it from falling down.

  In this installation mode, a metal fitting 11 that directly applies the back surface of the substrate to the wall surface (see FIG. 6) and provides a protruding portion to separate the receiving portion from the wall surface is used. “Floating tension” (see FIG. 8B). As the substrate 2, there are a fiber reinforced concrete plate and a thin steel plate, and both can be used without distinction between “directly attached” and “floating”.

  Generally, an epoxy resin is employed as the adhesive. This is because it is excellent in water resistance, weather resistance, and corrosion resistance, and furthermore, a certain degree of stability can be expected in the adhesion of the tile to the substrate, and today, the cost reduction is further advanced. By the way, among the above-mentioned substrates, the fiber reinforced concrete plate has a higher surface roughness than the steel plate, and the unevenness increases the entanglement with the adhesive layer. Therefore, there is little peeling of the adhesive from the substrate, which is convenient for sticking the tile.

  When the substrate is a steel plate, one that has been surface-treated for the purpose of rust prevention is used. The surface of the steel plate is smoother than a concrete plate without mirror finishing (buffing, etc.), but it must be improved in corrosion resistance and paint adhesion by plating or chemical conversion treatment. One of the plating processes is zinc hot-dip plating, but if the plating layer is thickened in order to improve rust prevention, the consumption of zinc increases. For example, unevenness with a change in layer thickness of about 50% occurs due to the use of the “deep soaking method”, which becomes more severe as the layer thickness increases. From the viewpoint of appearance, regardless of whether the layer thickness is large or small, it is generally put on the market as a smooth surface material by appropriate polishing.

  In the case of a tile panel in which the substrate is made of a steel plate, it cannot be said that the adhesiveness to the above-described epoxy resin is better than that in the case of a fiber reinforced concrete plate. Therefore, for example, additional post-processing such as applying a coating film as disclosed in Patent Document 1 is performed. It consists of an epoxy resin-based topcoat film that is formed of an epoxy resin with a rust-preventive pigment blended with a highly corrosion-resistant plated steel sheet, and has an average roughness of 1 to 3 μm as the center line average roughness due to the aggregate composition. Laminate. According to this, corrosion resistance is expected to be improved by the rust preventive pigment, and a galvanized steel plate or an aluminum plated steel plate can also be used as a substrate.

JP 2006-152569 A JP 2005-83031 A Paragraph 0035 of JP2003-268517A

  By the way, in the case of “floating tension” using the above-mentioned metal fittings, the substrate is maintained in a vertical posture, but in the case of “straight tension” in which the substrate is applied to the wall surface, even if the substrate is not completely on the curved surface of the tunnel wall. So that it is curved. If the substrate is brought into close contact with the tunnel wall having a curved surface with a radius of 5 m, the horizontal position of the tile results in a height of 10 cm. A gap is created. Since the epoxy resin is completely cured after curing, it is impossible to fill a 0.25 mm gap generated between the tile without bending and the bent substrate. Since it is impossible to change the thickness of the layer, it is inevitable that a large stress is accumulated in the layer, and over time, peeling is induced at the interface, and the adhesion ability of the adhesive layer is lowered. In addition, if voids are generated, groundwater or the like enters and accelerates the deterioration of the adhesive layer.

  On the other hand, when attention is paid to the upper edge and the lower edge of the tile, the corresponding portion of the substrate comes close to the tile that does not bend. As a measure for allowing this approach, it is necessary to consider that the tile cross section is formed in a boat shape extending in the vertical direction on the substrate facing surface side so that the bent substrate does not interfere with the upper and lower edges. Patent Document 2 proposes a tile panel that employs tiles that meet this purpose. Even in this case, since the curvature of the substrate generates a force that distorts the adhesive layer, the stress in the adhesive layer cannot be completely eliminated.

  Furthermore, at the time of manufacturing the tile panel, it is impossible to apply an adhesive to the entire back surface of the tile having a boat-shaped warp. In other words, the upper and lower edges of the tile and the parts close to each of the tiles must be intentionally an adhesive-free part or an incomplete adhesive part (hereinafter referred to as an adhesive ineffective area). If this is required, the tile panel can no longer be adopted. Assuming that 15% of the adhesive ineffective area is provided from the upper and lower ends of the tile, only 100-15-15 = 70% of the adhesive surface is secured. If so, that requirement will not be met.

By the way, in manufacturing a tile panel, when the substrate is made of a steel plate, as a temporary standard in hot dipping, the surface treatment is 10 g / m ² or more from the viewpoint of corrosion resistance, and from the viewpoint of moldability. It is desirable that it is 350 g / m ² or less (see Patent Document 3). Therefore, the steel plate substrate is required to have excellent adhesiveness while keeping this in mind.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its purpose is to provide a rough surface suitable for adhesion to the surface of a steel plate used as a substrate, and to tunnel a tile that does not bend. Even if the substrate that is bent along the wall surface comes close to the top and bottom edges of the tile, the tile and the substrate should be kept from interfering with each other. It is to provide a tunnel interior board in which tiles are adhered to a steel plate substrate that realizes that it can be prevented from occurring.

In the present invention, tile panels in which porcelain tiles are bonded vertically and horizontally on the substrate surface with an adhesive are arranged vertically and horizontally so as to extend along the tunnel wall surface, and the reflection function of the tile glossy surface is used to assist lighting in the tunnel. Applicable to tunnel interior panels. The feature is that the substrate is plated with a melt mainly composed of zinc, and the amount of zinc plating is 143 to 357 g / m ^2, and the change in the layer thickness after the “dipping” plating is removed. This is a plated steel sheet having a rough surface that has not been subjected to a post-treatment for increasing or decreasing the roughness.

  The adhesive is elastic adhesive 5 (see FIG. 1) that has a semi-permanent elasticity after application and has an elongation at break of at least 35%, and has an initial thickness of 0.3 to 0.5 mm. .

  As shown in FIG. 2, the back side long edge 1c of the tile is as high as possible with the back foot 1a, and the back side long edge is also attached to the substrate with an elastic adhesive. deep.

  The melt contains aluminum and magnesium. The elastic adhesive may be a modified silicone resin adhesive.

  The thickness of the tile is 7 to 9 mm, and the depth of the groove 1b forming the back foot 1a is 0.2 to 0.4 mm.

  Referring to FIG. 5, when anchors 8 are fixed to the concrete tunnel wall 4 by hitting anchors 8 at some of the tile joint intersections 9, the joints lined up and down to hit the anchors. The fiber reinforced concrete strip 10 may be disposed on the back surface of the steel plate substrate corresponding to the portion 9 so as to extend vertically.

According to the present invention, the substrate is plated with a melt mainly composed of zinc and is a galvanized steel sheet having a rough surface state in which the amount of galvanized coating is 143 to 357 g / m ² , so the average thickness of the plating layer is 20 Or 50 μm is secured. The resulting surface layer interspersed with 10 to 25 μm deep dents achieves strong entanglement of the adhesive. Peeling of the adhesive layer from the substrate is remarkably reduced, and an adhesive force convenient for holding the tile is exhibited. Of course, an inexpensive steel plate can be used as the substrate because no post-treatment for increasing or decreasing the roughness is required.

Since the plated layer having a thickness of at least 10 μm is provided on the back surface of the steel sheet to which no tile is attached, an adhesion amount of 10 g / m ² or more, which is indispensable from the viewpoint of corrosion resistance, is achieved. The The amount of adhesion of about 350 g / m ² or less, which is preferable from the viewpoint of workability, is also satisfied.

  It is an elastic adhesive with an elongation of at least 35% at the time of tensile break, and its initial thickness (free thickness at no load after completion of coating curing) is set to 0.3 to 0.5 mm. The wax void is filled with a thickened adhesive layer, and groundwater does not enter the adhesive interface.

  The back side long edge of the tile is as high as possible with the back foot, and the elastic adhesive is applied to the back long side edge, so that it is easy to achieve full adhesion of the tile.

  If aluminum and magnesium are included in the plating melt, a zinc-aluminum-magnesium alloyed plating layer is formed. As a result, aluminum improves the corrosion resistance of the base metal, and magnesium improves the corrosion resistance of the zinc plating layer. Improve.

  If the adhesive is a modified silicone resin adhesive, high resilience is exhibited, and the elasticity can be diversified to exhibit an elongation at tensile break of 35% or more. Adhesive quality according to the allowable elongation The selection range of is expanded.

  If the tile thickness is 7 to 9 mm and the depth of the groove forming the back foot is 0.2 to 0.4 mm, the thickness of the adhesive layer in the groove is such that the initial thickness is 0.3 to 0.5 mm. Is 0.5 to 0.9 mm. Since the stress generated by the extension of the adhesive layer in the groove is lighter than that outside the groove, the stress in the layer in the extension of the adhesive layer on the sole surface is relieved from the upper and lower regions.

  When fixing a steel plate substrate that is straight and anchored to some of the tile joint intersections to the concrete tunnel wall, it is attached to the back surface of the substrate corresponding to the joint intersections that are lined up and down. If the fiber-reinforced concrete strips are arranged so as to extend vertically, the groundwater flowing along the tunnel wall flows down without touching the substrate. That is, the fiber-reinforced concrete strip functions as a spacer that secures a space for drainage between the substrate and the tunnel wall.

The board | substrate adhesion | attachment form figure of the principal part which was a part of the principal part which exaggerated and represented the adhesive layer thickness of the tunnel interior board which stuck the tile to the steel plate board | substrate which concerns on this invention, Comprising: The three-plane figure and sectional drawing of the tile single-piece | unit whose back side long edge part is the same height as a back foot. The enlarged view of a plating layer structure. Layer deformation diagram exaggerating the adhesive layer thickness when the back long edge is at the same level as the groove bottom and the back long edge is at the same height as the back foot, and the long edge is Explanatory drawing of the behavior of the elastic adhesive at the time of tile stripping when it is at the same level as the back foot. The front view and sectional drawing at the time of arrange | positioning so that a fiber reinforced concrete strip may extend up and down on the back surface of a tile panel. A construction diagram showing a construction state and a partial enlargement of the tunnel wall. The three-side view and sectional drawing of the tile panel directly stretched. The front view and side view of a tile panel suspended.

  Below, the tunnel interior board which stuck the tile on the steel plate board | substrate which concerns on this invention is demonstrated in detail, referring drawings. In FIG. 7, tile panels 3 in which porcelain tiles 1 are bonded vertically and horizontally on the surface of the substrate 2 with an adhesive are arranged vertically and horizontally so as to extend along the tunnel wall 4 (see FIG. 6: upper and lower two levels)) FIG. 3 is an example of a tunnel interior board that uses a reflection function of a glossy tile surface to assist lighting in the tunnel. As the substrate 2, a steel plate is adopted because it is excellent in fire resistance, contamination resistance, durability, and weather resistance, and a substrate having a thickness of about 1 mm is used.

  The tile 1 has a thickness of 8 mm, and the depth of the groove 1b forming the back foot 1a shown in FIG. 2 is 0.3 mm, the groove width is about 7.5 mm, and the groove interval is about 8.5 mm. The long side edge 1c on the back surface of the tile is flush with the back foot 1a as much as possible (refer to the cross-sectional view taken along the line AA in FIG. 2). Substrate sticking with an adhesive is achieved. As the adhesive, an elastic adhesive 5 (see FIG. 1 in which the thickness of the adhesive layer is exaggerated) is used, which is typically a modified silicone resin system.

The substrate 2 is plated by being soaked in a melt mainly composed of zinc, and the amount of zinc plating is 244 g / m ² , and the surface is not subjected to post-treatment for increasing or decreasing the roughness. belongs to. Since the specific gravity of zinc is 7.14, as a result, the average thickness of the plating layer 6 becomes 34 μm, and the smoothing process by the polishing process by buff or the like is not substantially performed. Therefore, FIG. As shown in FIG. 3, the surface is a low-gloss surface with unevenness 6a remaining.

  The elastic adhesive becomes a rubbery elastic body after curing, exhibits semi-permanently high elasticity, and has an elongation at tensile break exceeding 35%. Various adhesives can be manufactured, such as those exhibiting 200% elongation at break at tensile break, and are therefore adhesives with high room for selecting performance and quality according to the required elongation.

  The coating amount of the elastic adhesive having an elongation at the time of tensile break of at least 35% is set so that the thickness after curing (hereinafter referred to as the initial thickness) is typically 0.4 mm. It may be in the range of 3 to 0.5 mm. Specifically, this initial thickness is the layer thickness on the substrate that is placed flat after curing of the adhesive application. That is, the free thickness when the elastic force due to the bending of the substrate has not yet occurred in the adhesive layer.

  The cover of the separation area due to the curvature of the substrate 2 generated in the central portion of the tile is filled with the stretch of the elastic adhesive layer, and the tile is not peeled off from the substrate. It also prevents groundwater from entering the bonding interface. By the way, it is not always necessary to increase the layer thickness of about 0.25 mm pointed out at the beginning of the “problem to be solved by the invention” at the center of the tile. When the adhesive layer 7 (see FIG. 1) is formed by the elastic adhesive 5, the substrate 2 approached by bending along the tunnel wall at the upper edge 1M and the lower edge 1N of the tile as shown in FIG. This is because the adhesive layer of the part is compressed, and this compression amount cancels a part of the thickening amount required at the central part of the tile.

  If the elongation in tension and the shrinkage in compression are the same, the 35% elongation should satisfy the “0.25 / 2” mm increase. Assuming that the initial thickness is a, and this 1.35 times is “initial thickness a + 0.25 × (1/2)” mm, a = 0.357 mm. If 1.35 times the initial thickness a is “initial thickness a + 0.25 × (2/3)” mm, then a = 0.476 mm, and “initial thickness a + 0.25 × (1/3)” mm. a = 0.238 mm. As described above, if the elongation in tension is 2 to 1/2 times the contraction in compression, the actual phenomenon is sufficiently covered. Certain initial thicknesses are not off-target.

  Incidentally, the initial thickness of the elastic adhesive having an elongation at tensile break of 50% may be about 0.2 to 0.4 mm. These are calculations, but it is a matter of course that the coating layer may be made thinner as the elongation percentage at the time of tensile fracture increases. However, it goes without saying that it is necessary to ensure the durability and performance of the tile panel on the safe side, and it is understood that the selection of 0.3 to 0.5 mm described above is appropriate. This keeps the function of the elastic adhesive to an indispensable level, avoids excessive quality, and suppresses the increase in tile panel manufacturing costs due to the expensive adhesive.

  As shown in FIG. 4, the force generated by the compression of the adhesive layer 7 generated at the upper edge 1M and the lower edge 1N of the tile is balanced with the tensile force of the adhesive layer at the center of the tile. Generate power. Epoxy resin adhesives that do not harden after coating and cause no change in layer thickness have no room to generate internal force, and the adhesive layer deteriorates and peels off. Nor. Since the elastic adhesive allows the layer thickness to be changed, the occurrence of peeling and dropping of the tile from the substrate is extremely reduced.

As described above, the substrate is plated with a melt mainly composed of zinc, and the coated surface of the rough surface is 143 to 357 g / m ² which covers the above 244 galvanization amount. deep. As a result, a plating layer of 20 to 50 μm is formed. Even if there is an unevenness of about 50% in the layer thickness, a complete plating layer area having a height of 10 to 25 μm is secured. Since unevenness of the same size exists on the surface layer, strong entanglement of the adhesive 5 that is convenient for tile holding is achieved. Since the post-treatment for increasing or decreasing the roughness is not required on the front and back, the substrate becomes an inexpensive plated steel sheet, and the tile panel is promoted to be inexpensive.

As described above, the plating layer thickness of at least 20 μm is also present on the steel plate back surface and each end surface on which the tiles are not adhered, so that the adhesion amount 10 g / m ² or 10 (g / m) which is indispensable from the viewpoint of corrosion resistance. ² ) ÷ 7.14 (g / cm ³ ) = 1.4 μm or more is achieved. It can also be seen that the amount of adhesion is about 350 g / m ² or less, which is preferable from the viewpoint of workability.

  The thickness of the tile 1 is 8 mm, but it may be 7 to 9 mm. If it is too thin, it will crack during transportation. If it is too thick, it will cause an excessive weight gain of the tile panel. Consideration is also given to handling in tunnel construction where medium and large heavy machinery is difficult to introduce. The depth of the groove 1b forming the back foot (see FIG. 2) is typically 0.3 mm, but if it is in the range of 0.2 to 0.4 mm, it will not affect the cracking of the tile, adhesion Integration by adhesion and biting with the agent is promoted, and interface deterioration can be prevented from occurring at an early stage.

  By the way, since the depth of the groove forming the back foot 1a is 0.2 to 0.4 mm, considering that the initial thickness is 0.3 to 0.5 mm, the adhesive layer thickness in the groove is 0.5. Or 0.9 mm. The internal stress generated by the extension of the adhesive layer in the groove is reduced more than in the outside of the groove (back foot part), but this reduces the intra-layer load in the extension of the adhesive layer on the back foot surface from the upper and lower adjacent areas. Works.

  As described above, the back side long edge 1c of the tile is as high as possible with the back foot 1a, and an elastic adhesive is also applied to the back long side edge of the tile. It is extremely easy to achieve a bonding area ratio of 75% or more and to regard it as a full adhesion). The elongation of the adhesive layer at the central part of the tile due to the bending of the substrate causes the adhesive layer at the edge of the tile to be compressed, and the resulting force acts as a reaction, allowing the layer elongation or thickening of the central part of the tile. . In FIG. 4, the back long edge 1c of FIG. 4A is at the same level as the bottom of the groove 1b, and the back long edge 1c of FIG. 4B is the same height as the back foot 1a. As can be seen, the latter generates a greater internal force than the former. This is because the resilience at the upper and lower edges 1M and 1N is increased.

  As shown in FIG. 4C, for example, when a force is applied to peel off the lower end of the tile, the adhesive layer at the upper end 1M is further compressed, and the increased elastic force reduces the lower end 1N from peeling off. Acts on direction. Therefore, tile peeling produces a tile holding force that is not exhibited in the case of an adhesive that does not deform the layer, and the back long edge 1c is at the same level as the bottom of the groove 1b as shown in FIG. 4A. It can be seen that a strong holding force is generated.

  Incidentally, the zinc melt for plating should contain aluminum and magnesium. As a result of forming a zinc-aluminum-magnesium alloyed plating layer, aluminum improves the corrosion resistance of the base material (steel plate), and magnesium improves the corrosion resistance of the galvanized layer. By the way, if antimony is also included in the plating solution, the adhesion of the coating film is improved. Therefore, even if the tile panel needs to be coated for some reason, a durable coating is realized.

As described above, the steel plate may have a thickness of 1.0 mm, but a steel plate having a thickness of 0.8 to 1.2 mm may be employed. It is also important to maintain surface rigidity as a tile panel and avoid weight. The plating adhesion amount is 244 g / m ^2, but is set to 143 to 357 g / m ² . The average layer thickness is 20 μm when the plating adhesion is about 143 g / m ² , but it has already been described that it is significant. When the adhesion amount is about 357 g / m ² , the average layer thickness is 50 μm. However, when the amount exceeds this, consumption of zinc or the like increases even if there is no problem with the thickness.

  By the way, as shown in FIG. 5, when anchors 8 are hit at some of the tile joint intersections and the tile panel 3 is fixed to the concrete tunnel wall 4, joints lined up and down where the anchors are hit. The fiber reinforced concrete strip 10 may be disposed on the back surface of the substrate corresponding to the intersection 9 so as to extend vertically. This kind of construction is actually lifted even if it is said to be straight. This functions as a spacer that secures a space for drainage between the substrate and the tunnel wall, and can prevent the groundwater traveling along the tunnel wall surface from touching the substrate.

  In tunnel interior construction, the tunnel interior board in which tiles are bonded to the steel plate substrate according to the present invention is not only used for the above-mentioned direct tension, but also as shown in FIG. It can also be applied to. In the floating tension using the metal fitting 11, the substrate is not bent so as to match the curved surface of the tunnel wall, so that the adhesive layer remains close to the initial thickness and the internal force does not accumulate or is extremely small. However, the uneven plating surface layer maintains the strong entanglement of the adhesive, and the tile is hardly peeled off from the substrate. If it can be used for both straight and floating tension, the effect of mass production of panels will be demonstrated.

  Although the present invention has been described with reference to a tile having a back foot as shown in FIG. 4, as can be seen from (c) drawn in contrast to FIG. Even so, the principle of adhesion and deformation in the adhesive layer on the plated surface is applicable. The principle of selecting the initial thickness is the same. Incidentally, the filling to the joint 12 between the tiles stuck vertically and horizontally in FIGS. 7 and 8 is performed after the tile panel is installed on the tunnel wall surface. In particular, when the substrate is directly stretched, the gap between the top and bottom of the tile is narrowed when the substrate is placed along the tunnel wall, and if it is packed in advance, there is a high possibility that the hardened joint agent may be broken and peeled off.

  DESCRIPTION OF SYMBOLS 1 ... Tile, 1a ... Back foot, 1b ... Groove, 1c ... Back long edge part, 1M ... Upper end edge, 1N ... Lower end edge, 2 ... Substrate, 3 ... Tile panel, 4 ... Tunnel wall, 5 ... Elastic adhesive , 6 ... plating layer, 7 ... adhesive layer, 8 ... anchor, 9 ... joint joint, 10 ... fiber reinforced concrete strip.

Claims (7)

Tile panels with porcelain tiles adhered vertically and horizontally on the substrate surface with adhesive are arranged vertically and horizontally to extend along the tunnel wall surface, and the reflection function of the tile glossy surface is used to support lighting in the tunnel. In the tunnel interior plate, the substrate is plated with a melt mainly composed of zinc, the amount of zinc plating is 143 to 357 g / m ^2, and the roughening is removed to remove the layer thickness change after “dipping” plating. A tunnel interior board in which tiles are attached to a steel plate substrate, which is a rough surface plated steel plate that has not been subjected to post-increase / decrease processing.
  The adhesive is an elastic adhesive that has a semi-permanent elasticity after application and has an elongation at break of at least 35%, and has an initial thickness of 0.3 to 0.5 mm. A tunnel interior board in which tiles are attached to a steel plate substrate described in Item 1.   2. The back long edge of the tile is as high as possible with the back foot, and the back long edge is also attached to the substrate with the elastic adhesive. Or the tunnel interior board which stuck the tile to the board | substrate made from the steel plate described in Claim 2.   The tunnel interior board which stuck the tile to the steel plate-made board | substrate as described in any one of Claim 1 thru | or 3 characterized by the above-mentioned.   The tunnel interior board having tiles attached to a steel plate substrate according to claim 2, wherein the elastic adhesive is a modified silicone resin adhesive.   The thickness of the tile is 7 to 9 mm, and the depth of the groove forming the back foot is 0.2 to 0.4 mm, according to any one of claims 1 to 5. Tunnel interior board with tiles attached to a steel plate substrate.   When the anchor is placed on some of the tile joint intersections and the substrate is fixed to the concrete tunnel wall, the back surface of the steel plate substrate corresponding to the joint intersections that are lined up and down 7. A tunnel interior board in which tiles are bonded to a steel plate substrate according to any one of claims 1 to 6, characterized in that the fiber reinforced concrete strips are arranged so as to extend vertically. .