The present invention relates to a method for stabilizing a ground, by which dry materials contained in at least two different tanks are mixed together in the desired proportions and transferred to the ground. Furthermore, the present invention relates to a system for stabilizing the ground, which comprises tanks for dry materials, which are to be mixed, and apparatuses for mixing the materials and for transferring them to the desired place.
Soft ground is an obstacle to the effective use of large areas of land. There are currently existing methods and systems, which can stabilize the soft material in the soil, and the land area can in this way be made useful. Vertical pillars, or corresponding supports, which are produced by mixing materials, which are known to be stabilizing materials into the soil, can be formed in the ground. Mixing the substance into the ground and the stabilization of the ground transpires, for example, by drilling a special boring implement into the ground, which disperses the stabilizing substance into the soil when it is turned, and at the same time mixes it into the soil materials.
In dry deep mixing a dry substance, which is made from at least two raw materials, is generally used as a stabilizing substance. At present, the raw materials are mixed together, for example, in a factory and are transported to the work grounds as a prepared mixture in a separate tank. The substance is transferred from this tank to the ground as needed using a work implement. The problem is that, at present, the information about and the control of the quantities of raw materials and the proportions in which they are mixed is not accurate. Different soils react differently to different binding agents, both qualitatively and quantitatively, so that they could be altered according to the circumstances. The current problem is that the proportions of the materials contained in the substance in the tank cannot be modified in a simple way after they have been mixed together.
In documents DE-A-4013801 and EP-A-0482720 has been presented methods and devices for dosing and mixing raw materials. However when mixing raw materials there is always water used and so these documents describe wet mixing methods.
The object of the present invention is to provide a method for stabilizing the ground, by which the disadvantages associated with the present method will be eliminated. In particular, the object of the invention is to provide a method, which uses one system to both mix together different raw materials in the desired proportions and to transfer them to the desired place. Furthermore, the object of the invention is to provide a system, which is advantageous in its cost, and simple and functional in its structure.
The objective of the invention is accomplished with a method and a system, the characteristics of which are set forth in the claims.
In a method formed in accordance with the invention, dry raw materials are transferred from at least two tanks by compressed air produced in compressors, the dry raw materials are mixed together in a transferring pipe and the mixed substance is immediately transferred to the desired place by a feeding apparatus after it has been mixed. The method does not require the use of separate storage tanks, nor does the prepared mixed substance need to be transported, so that the method is more economically advantageous than the current method. Furthermore, the proportions of the raw materials in the mixture can reliably be maintained as desired, or they can be easily and simply altered according to specific circumstances.
To the system in accordance with the invention includes compressors for producing compressed air, which are connected to the pipes leading from the tanks, a transferring pipe is also a mixing apparatus for the raw materials, in which the raw materials are arranged to be transferred from their tanks in the desired proportions, and said mixing apparatus is connected to the feeding apparatus for the mixed substance. The system does not require a tank for the mixed substance; rather the system only has different tanks for the different stabilizing raw materials. A structure formed in accordance with the invention is simple, advantageous and functional.
In a certain advantageous application of the invention, a compressor unit has been arranged to every raw material tank of the system for transferring the raw material. The compressed air produced in the compressors enables the control of the transference of raw materials in the desired proportions from the tanks to the mixing apparatus and to the feeding apparatus.
In an advantageous application of the invention, the system comprises tanks, a transfer apparatus for the raw materials, a feeding apparatus and compressor units, all of which are arranged to a mobile carriage. Thus, the entire system can be transported to the desired place in the vicinity of the boring implement.
In the following advantageous application of the invention, the system comprises transducers, arranged on or near the tanks, for measuring the quantity of raw material, which comes from the tanks. The transducers enable the flow of raw materials coming from the tanks to be monitored accurately and the desired proportions can be maintained in the mixture, and/or changed to the desired proportion. The invention will now be described in more detail with reference to the accompanying drawing, in which
A system formed in accordance with the figures comprises tanks 1, 2, arranged to a mobile carriage 6, compressor units 5 located in the vicinity of the tanks, and apparatuses 3, 4 for mixing the raw materials and for transferring the mixed substance to the desired place. The number of tanks can vary in different applications of the invention, such that every stabilizing raw material has its own tank. Every tank has its own compressor unit 5. The pipes leading from the tanks function as the transferring apparatus 3, and the compressors are then connected to the pipes. These pipes are joined into one pipe by the pipe fitting 7 at the other end of the system, the one pipe being connected to the feeding apparatus 4. Thus, the flows of the raw materials coming from different pipes are mixed together, and the mixed substance is transferred to the feeding apparatus 4 and through it to the desired place. The feeding apparatus in the application according to Figure 1 is a conventional boom-like feeding apparatus. The system additionally comprises transducers (not illustrated in the figures), known per se, for measuring the raw materials coming from the tanks, and which are mounted to the tanks or in their vicinity.
In an application of a method formed in accordance with the invention, the raw materials in at least two different tanks 1, 2 are mixed together in the desired proportions in a pipe 3 which also functions as a transferring apparatus, and the mixed substance is led directly thereafter to the desired place with the help of the feeding apparatus 4, for example, with a boring implement into the ground. In the method, two or more different raw materials are mixed together in a controlled way and transferred to the desired place by compressed air. The transducers enable the quantity and proportion of the raw materials flowing into the mixture to be monitored. The proportions in the mixture can easily be regulated by changing the quantity of one or more of the raw materials. The system is controlled hydraulically and it functions by remote control, for example by radio control.
The invention is not limited to the advantageous application set forth herein. The invention is versatile and its form may vary within the frames of the idea of the invention put forth in the claims.