EP2281950B1

EP2281950B1 - System for treating underground fluids

Info

Publication number: EP2281950B1
Application number: EP20090008375
Authority: EP
Inventors: Pedro Gustavo Figuerola Garcia De La Pastora
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-06-26
Filing date: 2009-06-26
Publication date: 2012-07-04
Anticipated expiration: 2029-06-26
Also published as: EP2281950A1; ES2390742T3

Description

Object of the Invention

The present invention relates to a method for treating underground fluids that manages to capture, confine and route in a controlled manner the fluids present in the subsoil, without requiring ditches or great excavations, preventing the damage that these fluids can cause if they come in contact with constructive elements when they run freely in the subsoil.
In this way, the proposed method takes advantage of the characteristics of the soils to guide the water towards the desired areas, so that the original values are not altered; this is achieved by a mesh of multidirectional micro-ducts with collateral fluid diffusers.

Background of the Invention

The presence of water in the subsoil has always caused numerous problems in buildings, such as damp patches, filtrations, material damage, structural damage, destabilisation of supporting soil, different settlements, etc. All of these problems require an accurate diagnosis, the lack of one being one of the main factors in the failure of the solutions applied.
The problems caused by the presence of water in the construction can be important, as the aforementioned ones, dampness, structure rusting, cracks, softening of materials and many others. Each of these problems becomes a multidisciplinary task due to the great versatility of water and the ensuing difficulty of solving the problem, which requires a coordinated action of specialists such as building technicians, engineers, chemists, geologists, etc.
However, all of the problems have a common cause: the undesired presence of water.
There is currently great social awareness and concern for preserving old buildings which for many years have lacked any maintenance and which form part of our architectural heritage. Many of these are in terrible conditions, with serious structural and aesthetic damage which, in a high proportion, are due to the slow, gradual, persistent and merciless action of the water present in the subsoil.
The difficulty of correcting the problems caused by water, and in many cases the impossibility of eliminating them so that they do not occur again, makes the work required very costly and sometimes not viable. Currently, any rehabilitation project involves the application of several products for waterproofing, sealing, etc., which in turn involve complex and costly complementary work for installing these, in many cases requiring to destroy part of what we wish to preserve.
Water can cause many different problems in construction and civil work. The presence of water in direct contact with a building causes important damage, not only as regards the liveability of the building, but also damage to materials. Problems can also occur due to high water tables that alter the balance of the supporting ground. In urban areas the water table can change considerably over time. A rise caused among other factors by unforeseen neighbouring underground work will intercept the natural flow of underground water, potentially creating a dam that will rise the level until causing serious damage to the foundations of existing buildings, which were not designed for this situation, possibly even leading to excess pressure on walls or under pressure in floors, which can lead to water penetrating the building.
The techniques currently used to treat underground water and other fluids that affect buildings mainly involve constructing peripheral drains, wells, drainage pits, waterproofing systems, etc. Peripheral ditches are meant stop water from reaching the building, but these cannot be used in all cases, either due to the depth required or the existence of adjacent buildings. Wells and drainage ducts can cause serious damage to the building by attempting to lower the water table in a forced manner, thereby carrying away solid matter that will unbalance the supporting ground. Waterproofing systems in general present serious problems of application, and it is known that any pore in the application of these systems is enough for the erosive action of water to appear again.
It is known in the prior art the document US 2369006 . in the production of a panel for constructional purposes comprising a plurality of tubular elements arranged side by side of each other and in layers wherein the axes of the elements of each layer are right angles with respect to the axes of the tubular elements of the adjacent layers, the method consisting in coating a plurality of elastically deformable tubular elements of circular cross-section with adhesive, arranging said elements side by side and in layers with the axes of the elements of each layer at right angles with respect to the axes of the elements of the next succeeding layer, an exerting pressure in two direction at right angles to each other with respect to each layer of tubular elements transversely to the axes of said elements to urge them into close contact with one another and to produce a substantially octagonal cross-sectional structure of each of the tubular elements, and effecting a bonding a between substantially fiat sides where they are in engagement.
This invention relates to structural materials, particularly for aircraft or similar, using a plurality of tubular elements, which are bonded together and assembled in various ways in accordance with the structure desired. However, the proposed invention relates to a system for treating undergrounds fluids, so that the object of both patents is different.
Is also known in the in the prior art the document EP 0688906 . It relates to a ground water drainage network comprising a number of strips for embedding in the ground and forming a water permeable network or mesh structure characterised in that each drainage strip comprises one or more high tensile-strength fibre bundles and one or more drainage belts, one or more of said high tensile-strength fibre bundles being embedded in a polymeric material by a moulding process thereby forming said strip, the said strip having at least one recessed or channelled portion with the one or more water permeable drainage belts inserted therein. A plurality of said strips are arranged in coplanar, spaced parallel configuration and interconnected to form a mat. Transverse slats in spaced parallel configuration interconnect said strips.
This method has a plurality of drawbacks. In the first place, to implement the method, it should be necessary to excavate the soil and then, implement the system, with the associated costs. In this way, this method is only valid for free soil, without buildings built on it or similar. Moreover, the method must be implemented "in situ", unable to implement it at a distance. And in addition, the system comprising a plurality of components to protect the conduits, which is strips comprising high tensile-strength fibre bundles and drainage belts being embedded in a polymeric material. All this components are necessary to protect the high tensile-strength fibre bundles.
The invention described below solves all this problems. The method can be implemented in both free soil and built soil, and it can be implemented remotely from the affected area. So, it is not necessary to dig in the affected area. Moreover, this method has not got a plurality of components, because it is not necessary complementary and protective structure for the micro conducts. This micro conduct is not manufactured in fibre bundles and they are hollow tubes.

Description of the Invention

The invention proposed solves the problems described above to full satisfactory. It is a method for treating underground water that does not seal or waterproof the soil, instead allowing a controlled flow of water in the subsoil.
The method proposed is meant to solve the problem from its origin and provides a definitive solution for professionals who face the task of solving this problem every day. It eliminates the problem of learning know-how for application, choosing types and models, conditions of implementation etc. as it is a single method applicable in any situation and condition.
The main characteristic of the invention lies in the elimination or re-routing of water, as the basic and single origin of all problems, without attempting to stop it or to waterproof the affected material, simply eliminating the contact between the material and the water.
In principle, it might seem that a building settled or placed in ground without water presence will not suffer from dampness. However, this is not possible. Buildings rest on the surface or under it, but their foundations reach the subsoil, which in turn is formed by different rocks. No rock is completely waterproof, and it is known that almost all soils show a strong anisotropy regarding infiltration, such that the horizontal permeability coefficient is at least five times greater than the vertical coefficient, and possibly even hundreds of times greater in stratified soils with interposed sandy layers.
The method described provides numerous benefits: it lowers the water table, cancels over-pressures and under-pressures, stabilises the supporting ground, eliminates filtrations, floods and dampness, eliminates contact between the material and the water and even prevents the formation of cracks, different settlements and fatigue processes in the constructive materials.
The method can be applied to numerous and diverse situations. For example, in civil work and construction it can be used to rehabilitate buildings with problems of dampness, degradation, etc. It can also be used to stabilise the ground, regarding the correct work of foundations, correction of banks or fillings affected by filtrations that could lead to earth slides or rock slides, drainage of containment walls suffering additional loads, depression or lowering of the water table, etc.
In addition to the applications in civil work and construction, the method proposed can be used to treat soil contamination. Thus, it can be applied to the investigation, control and processes of decontaminating soils affected by industrial spillage, urban spillage and hydrocarbon leaks, to recover leachates produced in uncontrolled dump sites, to protect bunds and banks in urban and industrial dump sites, or to provide protection against caving-in due to water filtrations.
This method providers heretofore unimaginable possibilities regarding rehabilitation of civil works and buildings, not by repairing the damage already caused but by eliminating the root cause of the damage so that it does not occur again. The integral action of the method and its form of application make unnecessary measures such as raising floorings or pavements and opening ditches for carrying out waterproofing work on walls and drains. It will conserve foundations and improve the supporting ground, without traumatic operations, without having to cut walls to install moisture barriers and without carrying out the costly and risky grouting meant to reduce the porosity of the constructive elements.
Another important advantage of the method proposed is that it maintains constant the characteristic humidity of each individual soil without drying it. When hydrated, materials soften and weaken, potentially leading to crushing or cracking. When their state changes from dry to moist or vice versa, their swelling coefficient (expansions or retractions) also changes, leading to material fatigue or degradation.
As specific applications in construction work, for example, the proposed method allows treating high water tables as, on occasions, in urban areas the water table can rise over time due to, among other reasons, adjacent underground work that may intercept the natural water flow. By implementing the described method it is possible to maintain or correct the water table, cancelling any effects of over- or under-pressures and maintaining the water flow constant.
It can also be applied to supply or sewer pipe breakages, which occur unexpectedly and can carry away fine elements and form hollows in areas of deficient compactation, possibly leading to collapses, undermining foundations, different settlements and sudden pavement breaks. In addition, sewerage leaks are particularly dangerous as they contain a concentration of chemical reagents that can attack constructive elements. The proposed method will in this case carry out a preventative task as it would absorb the leakage, preventing the damage that it could cause.
In soil formed by gravel and/or sands, the presence of a water flow with a high speed due to a high hydraulic gradient can carry away fine elements and lead to dangerous hollowing, undermining and different settlements. The method proposed allows capture, confine and route the water in a controlled manner, preventing these effects from happening.
The volume changes generally occurring in soils formed by silt and/or clay as a function of their water content is one of the main causes of serious problems in buildings, such as breakage of underground pipes, generalised cracks, different settlements, etc. In these cases, the typical solution is to underpin the foundations with micropiles to carry the load to depths that are not affected by variations in moisture. This has a high cost and, moreover, the effectiveness of underpinning the footings is uncertain, as many are not accessible. The method described provides an effective and selective alternative. Knowing the stratigraphy of the ground, the most permeable layers, formed by layers of silt or sand, are located, then installing a horizontal drainage network in the layers considered most critical to prevent an unforeseen presence of water or extended drought from affecting the clayey layers, which would lead to swelling or drying and thereby damage the building. The installation of said method can be performed before or during the construction of the building in clayey soils with expansive characteristics in order to prevent damages, as the effects of soil volume changes are never entirely reversible.
In evaporitic soils, such as gypsum or loam, water causes solution processes (karstification) such that in presence of a certain hydraulic gradient a flow is produced with a large amount of dissolved matter. This causes a quick loss of a large amount of mass in the ground, producing hollows and cavities that in turn allow a greater amount of water to pass, increasing the amount of material dissolved. The process can eventually lead to collapse of the ground subjected to the building load, resulting in specific collapses under the foundations. The method described by the invention can easily intercept the numerous gaps formed in this type of soil, and its mesh effect makes it essential as the optimum solution in these cases. As it is not necessary to dig trenches and the like, it is a highly profitable method. It even allows accessing the affected areas from a distance, and intercepts any fissures that may also affect the building to a lesser extent.
The proposed method involves implementing in the subsoil a plurality of microducts disposed subhorizontally, in different directions and even at different depths, from one or several suitably enabled areas, thereby achieving a mesh effect, either under or adjacent to the building to be treated, providing a drainage or infiltration network with a high efficiency, according to a prior study of the ground, which allows fluids to follow their natural course.
The method is implemented using high-quality and modern materials, fulfilling requirements such as: static load capacity on microducts, resistance to aging, resistance to chemical aggressions and high draining capacity (permeability). To obtain these characteristics, during the creation of the microducts the subsoil is treated by adding products to improve its capacity in insoluble materials and at the same time stabilise the wall and improve the aquifer layers, reducing the interaction of the clays and their inhibition, thereby suppressing the swelling effect of layers sensitive to water. Other products will prevent the agglomeration of solid matter and the resulting formation of "bridges".
The problem of the loads exerted on the microducts is solved by the materials used in their coating, which have physical properties that allow them to withstand these loads, as well as solving the complex operation of redistributing loads.
The problem of aging due to the heat produced in potential biochemical reactions inside the microducts that could lead to their softening is solved by using these high-technology materials, as well as by a thorough control of the raw materials used. The product finally obtained has chemical stability in all types of waters, particularly seawater and saline, acidic or alkaline diluted solutions. The use of materials with these special characteristics results from regular analyses of water obtained from drainages, which in some cases have a concentration of chemical reagents that requires the use of elements perfectly suited to this type of aggression.
In this way, the method proposed, by creating a suitably sized three-dimensional network of microducts, provides a surface with a high infiltration that covers an area as large as needed. This method also reduces the cost of operations with the same intended effect, as it eliminates the need to replace soil, fill ditches, etc. and does not damage constructive elements.
The method for treating underground fluids from any point, inside or outside the building, allows implement the mesh in the area with greatest water flow without having to cover areas that do not have any problem and without limits imposed by the existence of adjacent buildings. In addition, it does not dry the ground, allowing to maintain its characteristic humidity or specific retention coefficient, conserving its natural hygroscopic conditions and managing to stabilise it. As there is no change from dry to wet conditions or vice versa, the swelling coefficient of the materials is not altered.
In addition, given the disposition, shape and dimensions of the collateral diffusers used and as no forced aspiration system is used, the natural flow rate is not affected and therefore no fine particles are carried away and there is no ground settling.
The method can always be expanded if subsequent circumstances require covering other areas, and can similarly be regenerated, so that it is a definitive method. A simple trapdoor allows future access to carry out any subsequent tasks.
The method can be implemented under buildings, under the foundations, between piles or footings, to create a base drainage even in previously-built buildings as well as between dividing walls.
As indicated above, the method proposed can be applied to all types of apartment buildings detached homes, industrial buildings, etc., allowing to treat expansive ground even in areas where a high piezometric level causes frequent damage to buildings, such as destabilisation of the ground and resulting breakage in supply or sewer pipes, different settlements, etc.

Description of the Drawings

To complete the description being made and to aid a better understanding of the characteristics of the invention, according to an example of a preferred embodiment thereof, this description is accompanied by a set of drawings that form an integral part of it and where, for purposes of illustration only and in a nonlimiting sense, the following is shown:

Figure 1 shows a schematic representation of a possible application of the described method. The microducts (1) are placed under a building with a garage built under its ground floor (8). They are disposed under the pillars (6) and footings (5), so that all this work under the subsoil can affect the water table (7), not only by itself but due to infiltration of rainwater and other fluids. The microducts (1) are placed at different heights and directions, so that when looked at from above (plan view) a mesh would be seen allowing water to pass from one side to the other of the construction, channelling and re-routing it without obstruction or blockage under the building.
Figure 2 shows the design of the microducts (1), on the outer surface of which are provided the lateral diffusers (3). In some cases the microducts can have an inner tube (12) with some orifices (13).
Figure 3 shows a schematic representation of a building (9) supported on footings (5), wherein the water saturation area, represented by the broken line, has risen to said footings (5), potentially leading to damp patches by capillarity or any other associated damage. For this reason, the microducts (1) are placed under said building (9), so that the saturation level will fall or re-circulate until it is under the level of the footings (5), preventing damage to the building.
Figure 4 shows the saturation level of Figure 3 lowered by the method described in the invention by means of the microducts (1).
Figure 5 shows a schematic representation of another application of the method of the invention under a building.

Preferred Embodiment of the Invention

The invention proposed consists of a method for treating underground fluids that allows stabilising the ground by channelling said fluids such that the natural levels of the subsoil remain constant. It allows treating the ground from any point, either inside or outside the affected area, and also allows directing the microducts toward the affected area without having to cover areas that do not have problems, and without limitations due to the presence of adjacent buildings. It also prevents drying out the ground, allowing maintain the humidity level or specific retention coefficient of the ground, conserving its natural hygroscopic state.
The method described comprises the following steps:

(a) prior study of the stratigraphy of the ground and locating the most permeable layers,
(b) creating an area (2) for the establishment of the appropriate elements for implementing the method, such as a pit or the like so that,
(c) creating, at different heights and directions, a plurality of horizontal perforations with a small inclination that cross the area to be treated,
(d) introduction of a plurality of micro ducts (1) from the enable area (2) by the perforations that cross the area to be treated, creating a horizontal mesh of micro ducts (1) at different heights and directions under the central core of the affected area (4)

As no forced aspiration system is applied, the natural flow rate is not affected and therefore there is no carrying of fine particles or ground settlement.
The method described comprises a plurality of micro ducts (1) disposed at different heights and horizontally with a slight inclination, using an area (2) enabled for implementing the method, such as a pit or the like so that, after a prior study of the stratigraphy of the ground and locating the most permeable layers, each microduct (1) is placed in the direction and layer appropriate for treating the subsoil, creating a type of horizontal mesh, with each microduct (1) having collateral fluid diffusers (3), capturing confining and routing the fluids under the building, thereby stabilising the subsoil and ensuring that the fluids follow their natural course under the ground.
This method does not require construction work under the affected building or any other building, instead preparing an enabled area (2) for establishing the system from where the micro ducts (1) are introduced which is outside of the affected area (4), the affected area being that which requires treatment for drainage or infiltration of fluids.
The microducts (1) can be disposed in any direction and from different enabled areas, so that, for example, it is possible to dispose a plurality of microducts (1) at a certain height from one enabled area, horizontally and with a slight inclination, and another plurality of microducts (1) from a different enabled area, at a different height, also horizontally and with a slight inclination such that, for example, they are at 90° to the each other. In this way, a mesh of microducts (1) is generated in which the fluids move freely, keeping constant the natural level of water in the subsoil.
The microducts (1) are introduced from the enabled area (2) by horizontal perforations that cross the area to be treated, creating a horizontal mesh of microducts (1) at different heights and directions under the central core of the affected area (4).
The design of the microducts (1) is such that it prevents undesired particles from passing, allowing to filter only the desired particles. Thus, the microducts (1) comprise an outer tube (11) with the collateral diffusers (3) and an inner tube (12) with orifices (13), so that the opening of the microducts (1) is calibrated to prevent undesired elements from passing.
When the horizontal perforations are made from the enabled area, if the direction they follow leads to an area full of fluids, these will be expelled as the subsoil is perforated, thereby complicating the insertion of the microducts (1) and forcing through them particles that should not pass. To prevent this, when the horizontal perforations are made a biodegradable polymer is first injected to prevent the passage of a large amount of fluids before introducing the microducts (1), as this simplifies their introduction and the polymer will disappear in time.
Similarly, although this polymer disappears in time, in order to accelerate this process, after introducing the microducts (1) in the horizontal orifices an equally biodegradable polymer is injected which has the opposite effect to that of the polymer used before introducing the microducts (1), restoring the circulation of fluids through the aforementioned microducts (1).

Claims

Method for treating underground fluids under a building comprising
(e) prior study of the stratigraphy of the ground and locating the most permeable layers,

(f) creating an area (2) for the establishment of the appropriate elements for implementing the method, such as a pit or the like so that,

(g) creating, at different heights and directions, a plurality of horizontal perforations with a small inclination that cross the area to be treated,

(h) introduction of a plurality of micro ducts (1) from the enable area (2) by the perforations that cross the area to be treated, creating a horizontal mesh of micro ducts (1) at different heights and directions under the central core of the affected area (4)
where each micro duct (1) having collateral fluid diffusers (3), capturing confining and routing the fluids under the building, thereby stabilising the subsoil and ensuring that the fluids follow their natural course under the ground.
Method for treating underground fluids, according to claim 1, characterised in that the enabled area (2) for the introduction of the microducts (1) is placed outside of the affected area (4), the affected area being that which requires the fluid drainage or infiltration treatment.
Method for treating underground fluids, according to previous claims, characterised in that the micro ducts (1) are introduced from the enabled area (2) through horizontal orifices that cross the area to be treated, creating a horizontal mesh of micro ducts (1) at different heights and directions under the central core of the affected area (4).
Method for treating underground fluids, according to previous claims, characterised in that the micro ducts (1) comprise an external tube (11) with the collateral diffusers (3) and an internal tube (12) with orifices (13), so that the opening of the micro ducts (1) is calibrated to prevent passage of undesired elements.
Method for treating underground fluids, according to previous claims, characterised in that, in method step (c), when the horizontal orifices are made, a biodegradable polymer is injected in them to prevent the passage of a large amount of fluids before introducing the micro ducts (1) which helps to introduce them and disappears after some time.
Method for treating underground fluids, according to previous claims, characterised in that after the step (c) of introducing the micro ducts (1) in the horizontal orifices, a biodegradable polymer is injected with the opposite effect to the one injected before introducing the micro ducts (1) which restores circulation of fluids through the micro ducts (1).