ES2220199B1 - CONTINUOUS EXCAVATION SYSTEM OF WALLS SCREEN. - Google Patents

Abstract

Continuous excavation system of screen walls. The system is based on the use of a spoon whose jaws (3) have a system that drives the material or land to a loading chamber (4) equipped with non-return gates (5), passing the material from it to a chamber of pre-filtering (6) where the pressing of the material and the elimination of liquids and bentonite sludge is carried out, through filtering walls that delimit said pre-filtering chamber (6), following which there is an exit section (7) of feeding of the pressed material and free of liquids and sludges, towards a continuous conveyor means (8) constituted by a vertical conveyor in endless circuit. The system allows digging, extracting and unloading the material to the surface, in a totally continuous way without interrupting the excavation to extract it with the jaws (3) to the surface, as it happens conventionally. In addition, the extracted material is a compacted material that is inert and is not dangerous from an environmental point of view.

Description

Continuous wall excavation system screen.

Object of the invention

The present invention relates to a system of continuous excavation of screen walls, whose obvious purpose is to dig the ground and extract it to the surface, without interruptions during the process. In addition, the system is planned so that the extracted material is compact and free of mud bentonite that is used during the excavation on which it has been of making the wall or screen, so that this material solid extracted and compacted is a true inert for purposes of discharge and not dangerous from the point of view environmental.

Background of the invention

In a large majority of the buildings that are perform underground, such as parking lots, basements and buildings in general, it is necessary to perform as a previous step a screen wall around the construction, in order to close e waterproof the construction itself, as well as hold the ground external during the construction of the new structure, and even bear part of the burden of future construction.

The walls screens are usually made by cranes equipped with spoons that excavate and extract the ground to the surface, so that to prevent the walls of the screen crumble while it is being built, during the phase excavation, the excavated hole is filled with bentonite sludge, so that the soil extracted and mixed with the mud Bentonite is loaded on trucks that transport it to landfills of inert, process that raises various problems, and may cite as more important the following:

-

The mixture. of land with bentonite mud, it is a product more or less liquid, so in the transport chain they are usually caused losses, with the consequent contamination, problem that worsens in urban environments.

-

The Bentonite, although it is a type of clay, is polluting. Whether discharge with very high water contents, produces pollution of the subsoil itself by leaching, and may also cause stability problems on the slopes of the stacks of the dump.

-

The problems referred to in the previous two points have led to some countries have restrictions regarding the use of bentonite.

\hbox{excavación.}

As for the means or systems of excavation of screen walls that are currently used, two fundamental systems can be cited, coupled both in one and in another case to a self-propelled crane, one of the systems consisting of the classic excavator bucket that excavates the ground by means of the respective spoon jaws, which extracts the material or soil together with a part of the drilling mud, so that the extraction time is considerable, being increased with the depth, since it is necessary to take out the spoon, unload it in the truck and reposition it at the point of

 \ hbox {excavation.} 

In addition to the loss of performance offered by the bucket system, the excavated terrain transports all existing contaminants in the subsoil and found dissolved in the ground water.

Another excavation system is known as Hydrofoil, which is a hydraulic drive system, more than drilling than digging, so that the ground is reduced by mechanical breakage to smaller sizes that are mixed with the mud bentonite to be transported to the surface by way hydraulics. The mixing with the mentioned mud is even higher to the traditional spoon and so is the mixing of the pollutants in the field, by increasing the washing due to the greater breakdown of materials and the system itself surface transport.

The spoon system referred to first is Hydraulic or even mechanical drive and is the most currently used, while the hydrophobic system is applied more frequently in rock formations or hard.

In accordance with the above, the systems of conventional excavations spend much of the time in extract the spoon to the surface, load it in the truck and return to descend to the point of excavation, waste of time that logically increases with the screen depth and that derives In poor performance.

Description of the invention

The system that is recommended has been conceived to solve the problem described above, as well as get a series of advantages that will be exposed throughout of this description.

More specifically, the system of the invention is based on extracting the material, compacted and released from the mud bentonitic, even part of the land's own water, thereby achieving greater ease in transport and waste without contaminants or added liquids, as well as a estimated decrease of 10% of the amount of waste coming of the bentonite mud.

On the other hand, consumption is also reduced of bentonite and water in the manufacture of mud, saving estimated at 10%, so taking into account that each of the teams will be able to excavate about 25 m 3 / hour and they work a average of 1500 hours per year, would mean an annual saving of 3750 m3 of water and more than 150 tons of bentonite, per team.

Another important advantage is to extract the ground without moving the bucket to the surface, increasing the yield up to 100%.

More specifically, the system of the invention is based on the use of spoon with jaws, but with some innovations that consist of arranging in the jaws some loading means, which transfer the interior terrain from the jaws to a loading chamber.

Another characteristic of novelty is that continuation of the aforementioned loading chamber a pre-filtering chamber, in which the ground is compressed or material that is excavated and extracted (preferably by a system of hydraulic presses), using filter walls to separate the solid material from the liquid, such as water, bentonite and other elements in suspension, getting the land or material is consolidated and ready for extraction and transportation

Another feature of novelty is that on departure of that pre-filtering chamber, a subsystem of surface transport of the pressed material. This system it may alternatively consist of one or several stages of loading / pre-filtering / output as described above, or be formed by a vertical conveyor in endless circuit, being able to be constituted by a tubular tape, a system of buckets, etc., being provided in any case to continuously transport the solid and compressed material that it is removed without having to transport the spoon to the top, unload on a truck, return to drive to the workplace, etc.

Description of the drawings

To complement the description that is being performing and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical realization of it, is accompanied as an integral part of said description, a single sheet of plans where illustrative and non-limiting nature a view has been represented of the bucket structure with the improvements that constitute the Excavation system of: screen walls made in accordance with the object of the invention.

Figure 1.- Shows the structure with the spoon in compression position.

Figure 2.- Shows the same view of the structure at the end of the loading phase.

Preferred Embodiment of the Invention

In view of the figures outlined you can observe how the screen wall continuous digging system object of the invention, is based on the use of a spoon conventional but with a series of improvements and innovations that they allow the extraction of the land to be done in a way compressed and free of bentonite sludge, without having to climb the spoon to the surface.

More specifically, the spoon on which the excavation system object of the invention comprises a support structure (1) that is complemented by elements of guided (2), all as conventional, including jaws (3) whose function is to dig the ground, being able to have any appropriate geometry to effectively comply with the desired function

Well, from these characteristics, a of the improvements of the invention is that inside of the jaws (3) a cargo pants (4) are provided as chamber and equipped with non-return gates (5). Another of the fundamental improvements of the system of the invention is that through the vertical movement of the jaws (3), it is achieved compress the ground against the pants (4), causing its introduction into the pre-filtering chamber (6), where, by effect of pressure and given its innovative configuration with walls filtering, excess liquid (water, bentonite and other elements in suspension), thus achieving that the land is consolidated and ready for extraction and transport.

During the stage of lowering of the jaws the floodgates (5) prevent the descent of the ground existing in the pants (4) and the pre-filtering chamber (6), allowing the opening of the jaws for a new cycle of excavation and loading

The repetition of these cycles is driving the compressed material towards the exit zone (7), from which the Pressed material itself, is fed to a system of transport (8), responsible for transporting the surface to pressed material, with the particularity that such means of transport (8) will consist of a vertical conveyor in endless circuit, such as a tubular belt, a system of buckets, etc.

The vertical movement of the jaws is performed by the action of hydraulic cylinders (9).

In this way the compressed soil is extracted and free of bentonite mud, even a part of the water of the land, which facilitates the transport of that land or extracted material and its disposal without contaminants or added liquids

In addition, there is a decrease in the amount of waste from bentonite sludge, estimated approximately 10%, reducing consumption of bentonite and water in the manufacture of mud, so the Estimated savings can also be estimated at 10%.

Another fundamental advantage is that the extraction of land is done without the need to move the spoon to the surface, increasing performance by up to 100%, since there are to keep in mind that it is frequently excavated on screen walls greater than 50 m deep.

Also noteworthy is the fact that the discharge of solid and compressed material or surface on the surface, It turns out to be a true inert and with a low capacity pollutant, that is, not dangerous from the point of view environmental.

Also noteworthy is the fact that the surface extraction of excavated material is performed from continuously, no need to transport the spoon out of the excavation, with a notable increase in productivity.

Claims (5)

1. System of continuous excavation of screen walls, which based on the use of a bucket with its corresponding digging and material extraction jaws, and a support and guidance structure for the means of the bucket assembly, is characterized in that between The jaws (3) of the bucket incorporates a loading chamber (4) of trouser type or other, receiving the subtracted material, following which a pre-filtering chamber (6) is provided in which it is made, by vertical displacement of the jaws, a compaction of the material and a separation with respect to the liquid components (water, bentonite and others in suspension), through filtering walls provided in the pre-filtering chamber (6). 2. System of continuous excavation of screen walls, according to claim 1, characterized in that the jaws (3) of the bucket, as well as the cargo pants (4) are operated by hydraulic cylinders (9). 3. Continuous excavation system of screen walls, according to previous claims, characterized in that the loading trousers (4) include non-return gates (5). 4. Continuous excavation system of screen walls, according to claim 1, characterized in that, at the outlet (7) of the pre-filtering chamber (6), means of transporting the pressed material are optionally incorporated. 5. System of continuous excavation of screen walls, according to claim 1, characterized in that the means of transport (8) can be constituted by a vertical conveyor in endless circuit, capable of being materialized in a tubular belt, a bucket system or the like.