Technical Field of the Invention

The invention concerns a method and a device for increasing a service life of a running area represented by a road for vehicles or an airplane runway.

State-of-the-art

Today’s roads or runways suffer from damage such as a deteriorated surface, however, only in some particular places. Nevertheless, the surface needs to be replaced as a whole. This is costly.

The aim is to enable to use a road or a runway for a longer time, whereas loading and damaging of the road is moved to places being undamaged so far.

Subject Matter of the Invention

A subject matter of a method for increasing a service life of a running area represented by a road for vehicles or an airplane runway consists in that at least two successive mutually related irregularities of a road running area are measured by a profilometer and an artificial irregularity is placed before the first of these irregularities in the direction of vehicles run; the artificial irregularity is of a similar size as the first irregularity in a form of a hump or a depression or of a size in the order of millimeters at the first irregularity in a form of a depression.

A subject matter of a device for increasing a service life of a running area represented by a road for vehicles or an airplane runway consists in an artificial irregularity attached to the road running surface in the direction of vehicles run before or around the first irregularity of a system consisting of one first irregularity and at least one related irregularity. The artificial irregularity in a form of a hump is of a similar size as the first irregularity in a form of a hump or of a size in the order of millimeters at the first irregularity in a form of a depression. The artificial irregularity has a depression shape and is of a similar size as the first irregularity in a form of a hump or of a depression at least in the order of millimeters and is separated from the first irregularity.

The artificial irregularity consists of a strip or an applied asphalt layer or an applied concrete layer or a milled-out groove and is placed before the first irregularity and/or before the last related irregularity. Overview of Figures in Drawings

The atached Figures show a schematic depiction of a road, i.e.

Fig. 1 shows a road with the first irregularity in a form of a hump,

Fig. 2 shows a road with the first irregularity in a form of a depression, Fig. 3 shows a road with the first irregularity and an artificial irregularity in a form of a hump,

Fig. 4 shows a road with the first irregularity in a form of a depression and an artificial irregularity in a form of a hump,

Fig. 5 shows a road with an artificial irregularity in a form of a depression and Fig. 6 shows a road with an artificial irregularity before and behind a system of three irregularities.

Examples of Embodiments of the Invention

Figure 1 shows an origination of a phenomenon called a spatial repeatibility. On road 1 there is the first irregularity 2 in a form of a hump. This irregularity causes occurrence of vibrations of a vehicle chassis. After the first irregularity 2 force peaks occur between a wheel and a road in congruent distances v/f because a wheel-base of an overall majority of vehicles has very similar dimensions and because the own frequency f of chassis of vehicles are highly conformal and because vehicles on a place of the first irregularity 2 move at a similar velocity v. These peaks in these congruent distances result in a cummulation of damages and a formation of related (subsequent) irregularities 3 and a surface cracking typically in a form of depressions that need to be repaired. This Figure and the following ones also show schematic depictions of a course of a vehicle chassis track between the first irregularity and the following irregularity/irregularities and thus a process of a vehicle spring suspension and a process of force relieving between a wheel and a road.

Related (subsequent) irregularities 3 are repaired on a road or a runway, even if a road or a runway is not damaged between the related (subsequent) irregularities 3. An influence of the first irregularity 2 is reflected in creating related irregularities 3 within appropriate distances v/f due to very similar dimensions and own frequencies of vehicles or airplanes. Vehicle chassis suspension is damped, therefore only two, three to four successive damaged places occur on a road within a spatial repeatability.

The first irregularity 2 can be considered an initial damage of the road in term of a mechanism of origination of road 1 damage, but usually it cannot be found out and determined as the initial cause of the originated irregularities in accordance with the described mechanism. Then it is the first of the irregularities and mutually related (subsequent) irregularities in the found out succession of irregularities, forming in this case three successive mutually related irregularities. This is a typical case, however, only two successive mutually related irregularities can be measurable.

Figure 2 shows an occurrence of a phenomenon called a spatial repeatability, similarly as in Figure 1, but here the first irregularity 2 on road 1 is in a form of a depression (a hole).

Figure 3 shows a proposed solution. The road is measured by a profilometer and height coordinates of a profile (irregularities) of the road are an obtained result. Nowadays a profilometer usually consists of a measuring car with several videocameras and a laser sensor for measuring a distance of video-cameras from the road during the measuring car run.

Measuring of the road irregularities by a profilometer leads to determining the spatial repeatability of irregularities on the road. This is determined either by a spatial correlation or a determination of positions of the highest/lowest irregularities or a Fourier analysis or their combination.

The spatial correlation consists in a calculation of a correlation of a road irregularities along the road longitudinal coordinate x with a signal abs(sin(x*frv)), where x is the road longitudinal coordinate, f is a typical frequency of a vehicle chassis and v is a typical velocity of a vehicle motion. At least two or three successive related deformations of the road need to be found out through the correlation.

The determination of positions of the highest/lowest irregularities consists in a determination of the highest and the lowest locations of a road profile and in searching for similar maximums/minimums within v/f distance. At least two or three successive related deformations of the road need to be found out.

The Fourier analysis process consists in a calculation of the Fourier transformation of a road profile and a determination of track spectrum values f/v. On their basis at least two or three successive related deformations of the road need to be found out.

Artificial irregularity 4 is then placed before such a determined first irregularity 2. Its size is similar to the found-out size of the first irregularity 2. Figure 3 shows a hump-type artificial irregularity 4. An example of a solution is that a width of artificial irregularity 4 is across the whole road lane, its length equals a double of a typical tyre trace size, its height in a case of the first hump-type irregularity 2 is congruent to a height of a hump of the first irregularity 2 (though at least in the order of millimetres) and its profile is of a cosine type. In the case of the first irregularity 2 of a depression (hole) type - Fig. 4, a height of a hump-type artificial irregularity 4 is 5-10 mm, however, it can correspond to a depth of the depression (hole).

Another example is that a width of artificial irregularity 4 is across the whole road lane, its length equals a half of a typical tyre trace size, its height in a case of the first hump-type irregularity 2 is congruent to a height of a hump of the first irregularity 2 (though at least in the order of millimetres) and its profile is rectangular. In the case of the first irregularity 2 of a depression (hole) type - Fig. 4, a height of a hump-type artificial irregularity 4 is 5-10 mm, however, it can correspond to a depth of the depression (hole).

This artificial irregularity 4 causes an occurrence of new spatial repeatability of irregularities resulting in new related irregularities 5. Artificial irregularity 4 has to be located at all determined threesomes of irregularities 2, 3, 3. A threesome of successive mutually related irregularities is a typical example but only two successive mutually related irregularities can be measurable. Placing of artificial irregularities 4 leads to increased loading of a road shifted from related irregularities 3 to new related irregularities 5.

This procedure can be further repeated and new related irregularities 5 can be moved on the road by adding artificial irregularities 4. This way the road is gradually used after related irregularities 3 also in new related irregularities 5.

Figure 4 shows a proposed solution as depicted in Figure 3, but the first irregularity 2 is in a form of a depression (hole).

If the first irregularity 2 is a depression (hole), then the hump-type artificial irregularity 4 can be of a height in the order of millimetres, for example 5-10 mm, but it can be congruent with a depth of the depression (hole). Its width is across the whole road lane, its length equals a double of a typical tyre trace size and its profile is of a cosine type. However, the best way to determine dimensions of artificial irregularity 4 is a computer simulation based on a measured profile of road 1 and parameters of typical vehicles. Then artificial irregularity 4 of a depression (hole) type can also be used for the first irregularity 2 of a hump type. Their sizes will be similar.

Figure 5 shows a proposed solution as depicted in Figure 4, but artificial irregularity 4 is in a form of a depression (hole). Artificial irregularity 4 in a form of a depression (hole) has to be separated from the first irregularity 2 in a form of a depression (hole). A width of artificial irregularity 4 is across the whole road lane, its length equals a double of a typical tyre trace size and its depth is congruent to a depth of a depression (hole) of the first irregularity 2 (though at least in the order of millimetres) and its profile is of a cosine type.

Figure 6 shows a solution as depicted in Fig. 3, whereas a road or a runway is used for vehicles run in both directions, then artificial irregularities 4 are placed both before the first irregularity 2 and behind the last related irregularity 3 , which takes-over a function of the first irregularity 2 in the case of a vehicle running from the opposite direction. This way the road can be adapted for both the run directions on a road or a runway.

Artificial irregularities 4 can consist of adhered strips, applied asphalt or concrete layers but also milled-out grooves on a road or a runway.

Strips are easily applied as a rectangular profile but rather of lower heights. Applied asphalt or concrete or a milled-out groove can be easily made as a cosine profile and higher heights as well.

All variants described above can be combined one with another. The best way to determine dimensions of an artificial irregularity is a computer simulation based on a measured profile of road 1 and parameters of typical vehicles.

This procedure leads to using a road for a longer time.