EP1496161B1 - Method for stabilising ground for a traffic route - Google Patents

Description

The invention relates to a method for stabilizing a ground for a traffic route, such as a road or a railway line, wherein at least one grave-shaped path is processed by loosening the soil material and mixing it with a stabilizing agent with a soil cultivation device in the direction of the route, whereby a reinforced Bottom wall is formed.

Such a method is known from the German patent application 195 42 031 and the Dutch patent application 1010451. By means of such a process, a traffic route can be formed relatively quickly in comparison to a conventional, time-consuming procedure with a sand body spill in areas with less load-bearing soil, such as loam / moor soils. An accumulated sand body requires a long settlement waiting time before the traffic route can be completed, while remnants require relatively much maintenance. With floor walls, a traffic route can not only be completed faster, but it also creates a low-setting construction and thus a reduction in the required maintenance.

The stabilization by the bottom walls is achieved by mixing the dissolved soil material with the stabilizing agent whose main component is cement, and the volume of which, according to the Dutch patent application 1010451, can be for example 10 to 25% of the volume of the dissolved soil material. After mixing, the volume of the mixture is therefore greater than the volume of the trench-shaped path. The additionally formed volume is transported away as excess material, to which a special discharge system was attached to the mixing chamber in the device according to the Dutch patent application 1010451. After completion of the floor walls, these extend, as stated in German Patent Application 195 42 031, in the path direction under the path to be applied or the railway line to be created.

With the invention, a further improvement, in particular strengthening, the stabilization of the soil is intended.

This is according to the invention in a method as defined by the appended claim 1 in that at least two bottom walls are formed in the path direction, which extend substantially parallel to each other, wherein as a result of the addition of the stabilizing agent Soil material, the mixture emerging from the trench-shaped sheet is leveled between and above the bottom walls to a layer which is processed with another tillage device such that this layer forms a unit with the upper ends of the bottom walls. With these measures, two adjacent bottom walls are connected to a monolithic, inverted U-shaped bottom profile with both vertical and horizontal load distributing effect, and also the connection of the vertical parts with the horizontal part is torque-fixed, whereby both the load transfer and thus the load capacity the traffic route is further promoted to the bottom walls, as well as a stable and durable construction is obtained. Added to this is the additional advantage that these effects are achieved by using an excess of mixture previously considered unnecessary and therefore to be removed, which is a direct and inevitable consequence of the manner in which the bottom walls are made.

In the above mentioned is spoken about at least two bottom walls. As a purely illustrative, non-limiting embodiment, a construction for supporting a lane with a tread width of 7.5 m is also discussed, below which four floor walls are mounted in the direction of the tarmac and is actually referred to as a composite, monolithic, inverted U-shaped bottom profile is. For the sake of brevity, the various forms of the floor profiles will continue to be referred to as tunnel profiles. In the above-mentioned similar cases, according to a further embodiment of the invention, it may be preferred that the leveled layer extends protrusively past an outer bottom wall. Then, a bottom wall would each extend mainly vertically below an expected lane of a road-loading wheel of a vehicle traveling over the road.

Depending on the desired thickness and thickness of the layer connecting the bottom walls to a tunnel profile, according to a preferred embodiment of the invention it is provided or not provided that on the leveled layer a further layer consisting of a mixture of sand, cement and any further additions , is attached; This additional layer is mixed with the leveled layer during processing. Thus, always exactly the desired layer thickness and thickness to realize.

In order to optimize the joining of the leveled layer with the bottom walls to form a tunnel profile, according to a further embodiment of the invention it is preferred that a subfloor of a layer of sand is applied for attaching the bottom walls, which in the processing of the leveled layer at least partially with the leveled layer is mixed. Thus, a particularly intensive, as well as controlled connection of the leveled layer with the upper ends of the bottom walls, which initially reached into the sand layer, to realize, and thus an optimal load capacity for the tunnel profile.

Before the completion of the traffic route after curing of the formed tunnel profile is provided that on a monolithic structure thus obtained, consisting of at least two bottom walls and one, these at their upper ends connecting and covering layer, further cover layers are attached. One can think of asphalt layers with or without at least one sublayer of mixed granulate or a railroad track with rails and sleepers with or without underlayer.

One can be particularly effective if the operation of solving the soil material in a trench-like path and mixing the dissolved soil material with a stabilizing agent with a cutting lance is performed, which is inserted in a more or less inclined state in the ground and then the processing of leveled layer and a possible attached thereto or below layer is performed with a milling roller whose axis line runs mainly parallel to the surface of the road to be formed.

With reference to an embodiment shown in the drawing, although only as a non-limiting example, the method according to the invention will now be explained in more detail. The simple illustration of the drawing in cross-section shows a road construction produced by the method according to the invention, the left part of the simple figure showing partly an intermediate phase during manufacture and the right part showing the finished road construction.

The construction shown in the simple figure forms a two-lane road with a fully hardened width of approx. 7.5 m and on the opposite sides a semi-hardened roadside of approx. 2 m. For the production of such a road, the procedure was as follows.

Starting from the original top of the soil 1, a layer of soil material of approx. 200 mm was excavated, with excavated grass and topsoil laid aside along the planned path. In the excavated part was then one, forming a subfloor sand layer 2 of about 200 mm poured. Four bottom walls 3 were then formed in the path direction with a cutting lance. By a cutting lance we mean a tilling device with the appearance of a chain saw with above-average dimensions, ie an elongated frame, which can have a width of several tens of centimeters and a length of several meters, around which a bucket wheel chain runs. The paddle wheels are shaped so that the soil material is not as for example An excavator machine is dug, but is solved. The soil thus dissolved in a trench-shaped path is then added with a stabilizing agent in suspension, for example at different injection sites along the frame. The main constituent of the stabilizer, for example, forms cement, but may also be any other suitable additive or a combination of materials. The shape of the paddle wheels is further selected so that not only the soil material is dissolved, but also dissolved soil material and added stabilizer are mixed intensively. By the cutting lance is moved in the direction of the train, so an uninterrupted bottom wall 3 with, for example, a depth of about 7 m and a width of about 0.35 m is formed, the center distance of the two adjacent bottom walls 3 is about 2 m.

By adding the stabilizing agent to the dissolved soil material and mixing it with it, a mixing amount is obtained which is greater than the soil dissolved in a trench-like path. If the additional amount obtained, which can not be accommodated in the bottom wall 3 and thus exits from the subfloor formed by the sand layer 2, is about 20%, this means that in the present case an excess of about 2m ³ / m road is formed , This excess is distributed over a width of 11.5 m, ie the intended roadway with semi-hardened roadside, which results in a leveled layer 4 with a thickness of about 170 mm. On this leveled layer 4, a sand layer 5 will then be applied to a height of about 300 mm above the original top edge 1 of the earth.

The layer structure thus obtained with a height of about 500 mm is shown in the left part of the simple figure. These layers are mixed together using a roller mill. By a milling cutter we mean a soil cultivation device with which at least one horizontal layer of material can be intensively mixed and homogenized. As can be seen in the left-hand part of the simple illustration, the bottom walls 4 extend with their upper ends into the sand layer 2 and are therefore taken along when processing the layer structure with the roller mill, so that the obtained, intensively mixed, horizontal layer 6 (see right part the simple figure) after curing together with the bottom walls 4 forms a one-piece, strong, torque-stable, stable and durable monolithic body, consisting of a horizontal load distribution layer supported by four vertical load-distributing layers integral therewith.

It is noted that the width of 11.5 m generally can not be processed at one time with a tiller moving in the direction of the road. The mixing or stabilization process is then commonly used several tracks instead. The positions of the bottom walls 4 with respect to the overlap between different webs is an important focus, in particular, such an overlap preferably does not have to be at the location of a bottom wall 4.

After in this way the rather than tunnel profile to be designated body was realized, it is a layer 7 of mixed granules with a thickness of about 250-340 mm attached and then a layer 8 of lightweight asphalt with a thickness of about 80 mm on a layer 9 of lightweight asphalt with a thickness of about 60 mm. By side stuffing using previously graved topsoil and grass, the road edges 10 are completed. Then, the path construction is completed by attaching an approximately 30 mm thick sound insulating cover layer 11.

Of course, many changes and variants are possible within the scope of the invention from the appended claims. First, it must be repeated that the above-mentioned embodiment shown in the figure is only illustrative. Thus, more or less than four bottom walls may be present, it is possible to eliminate one or both sand layers or to add or not to add other substances to them. Of course, the dimensions given are not restrictive and vary in many ways. The same applies to the shaping of the tunnel profile. Thus, the bottom walls can be less regularly distributed across the width of the tunnel profile, depending on the application. The latter can also be a railway track, in which case the processing of the tunnel profile is adapted to this purpose. Also, the bottom walls seen in the path direction may have a deviating from a flat plane shape, for example, zigzag or wavy stretch. Furthermore, the number of floor walls under the entire road does not always have to be the same. Thus, one or more additional floor walls can be built in places over a certain distance. Also, depth and thickness of the bottom walls may vary with each other or in the path direction. This also applies to the thickness and the width of the leveled wall connecting the bottom walls to form a one-piece tunnel profile, which may or may not project beyond the outermost bottom walls. The overhang may also be one-sided and the width of the overhang may change along the road.

Claims (7)

1. Method for stabilising ground for a traffic route, such as a street or a railway line, in which at least one ditch-shaped lane is machined in traffic route direction by a ground machining device by loosening of ground material and mixing the same with stabilisation means, thereby generating a strengthened ground wall in traffic route direction, characterised in that at least two ground walls being spaced with respect to each other are formed in traffic route direction, extending substantially parallel to each other, whereas as a consequence of the addition of the stabilisation means to the ground material the mixture emerging out of the ditch-shaped lane is planated in between and above the ground walls to form a layer, which is machined by a further ground machining device in such a way that this layer forms a unit with the upper endings of the ground walls.
2. Method according to claim 1, characterised in that the planated layer extends over a ground wall located outside.
3. Method according to claim 1 or 2, characterised in that a further layer consisting of a mixture of sand, cement and further possible additives is arranged on the planated layer; this further layer will be mixed with the planated layer during their machining.
4. Method according to any of the preceding claims, characterised in that a subgrade including a layer of sand is applied before arranging the ground walls; said layer of sand is mixed with the at least partially planated layer during the machining of the planated layer.
5. Method according to any of the preceding claims, characterised in that further cover layers will be applied on at least one in such way obtained monolithitic construction including at least two ground walls and one layer which connects and covers them on their upper endings.
6. Method according to any of the preceding claims, characterised in that the loosening of the ground material in a ditch-shaped lane and the mixing of the loosened ground material with stabilisation means is performed with a milling lance.
7. Method according to any of the preceding claims, characterised in that the machining of the planated layer and a potentially thereon or thereunder applied layer is performed by a milling roll.

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