WO2007008054A1 - Mould for creating artificial roughness that protects against scouring - Google Patents

Mould for creating artificial roughness that protects against scouring Download PDF

Info

Publication number
WO2007008054A1
WO2007008054A1 PCT/MX2005/000053 MX2005000053W WO2007008054A1 WO 2007008054 A1 WO2007008054 A1 WO 2007008054A1 MX 2005000053 W MX2005000053 W MX 2005000053W WO 2007008054 A1 WO2007008054 A1 WO 2007008054A1
Authority
WO
WIPO (PCT)
Prior art keywords
structures
submerged
roughness
objects
flow
Prior art date
Application number
PCT/MX2005/000053
Other languages
Spanish (es)
French (fr)
Inventor
Robie Bonilla Gris
Original Assignee
Instituto Politécnico Nacional
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Instituto Politécnico Nacional filed Critical Instituto Politécnico Nacional
Priority to PCT/MX2005/000053 priority Critical patent/WO2007008054A1/en
Publication of WO2007008054A1 publication Critical patent/WO2007008054A1/en

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02B—HYDRAULIC ENGINEERING
    • E02B17/00—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B17/0017—Means for protecting offshore constructions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/22—Moulds for peculiarly-shaped castings
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02B—HYDRAULIC ENGINEERING
    • E02B3/00—Engineering works in connection with control or use of streams, rivers, coasts, or other marine sites; Sealings or joints for engineering works in general
    • E02B3/04—Structures or apparatus for, or methods of, protecting banks, coasts, or harbours
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15D—FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS
    • F15D1/00—Influencing flow of fluids
    • F15D1/002—Influencing flow of fluids by influencing the boundary layer
    • F15D1/0025—Influencing flow of fluids by influencing the boundary layer using passive means, i.e. without external energy supply
    • F15D1/003—Influencing flow of fluids by influencing the boundary layer using passive means, i.e. without external energy supply comprising surface features, e.g. indentations or protrusions
    • F15D1/005—Influencing flow of fluids by influencing the boundary layer using passive means, i.e. without external energy supply comprising surface features, e.g. indentations or protrusions in the form of dimples
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15D—FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS
    • F15D1/00—Influencing flow of fluids
    • F15D1/10—Influencing flow of fluids around bodies of solid material
    • F15D1/12—Influencing flow of fluids around bodies of solid material by influencing the boundary layer

Definitions

  • the present invention relates to an improvement in the prevention of undermining or erosion around structures and objects submerged in a stream or flow and that are constructed by emptying.
  • Such structures can be piles and stirrups of bridges, piles, columns, supports of structures or of equipment or of machines, conduits and other objects.
  • the aforementioned structures and similar objects may be supported, anchored, driven or buried in the bed or bottom or in the margins of a gully or ravine, of a body of water or of an artificial conduit or of a river, lagoon, estuarine, Coastal or marine.
  • a frequent problem in the case of structures and objects submerged in bodies of water that have movement is the local undercutting or erosion of bottom material on which they rest, induced by the alteration of the current or flow caused by the presence of those structures and objects.
  • Said alteration consists of local increases in speed and in the appearance of secondary flows and stelae with eddies or vortices, called turbulent stelae.
  • the local undermining releases material from the bottom around the structures and objects and can reduce their support, thus threatening their stability and safety and those of the corresponding superstructure, where appropriate.
  • Bridge failures also imply a significant risk to public safety: human lives have been lost in these disasters.
  • the collapse of a bridge by undermining generally begins with the loss of support of one or more piles, which are the intermediate columns that support the superstructure of the bridge. It can also fail one of the stirrups, which are the supports of the ends of the bridge, where it rests on the banks of the channel.
  • structures susceptible to damage by local undermining are the piles, the columns, the supports of structures or equipment or machines, the pipes and other ducts and similar structures and objects, supported, anchored, driven or buried in the bed or bottom or on the • margins of a gully or ravine, of a body of water or of an artificial conduit or of a river, lagoon, estuarine, coastal or marine environment.
  • FIG. 1 shows a structure or object submerged in a cylindrical shape 10, supported by an undercut or erodible bottom 11.
  • This vortex surrounds the structure or the submerged object and propagates downstream, releasing material from the bottom 11 around said structure; that material is then dragged by the current, thus forming the undercut pit 15.
  • the horseshoe vortex is especially important in the case of submerged structures in a vertical position or close to it.
  • Second mechanism von Karman vortices (Fig. 1) .-
  • the flow surrounding the structure or the submerged object 10 produces vortices 14 called vortices of von Karman Said vortices tend to form periodically and alternately on one side and the other of the submerged structure or object and are carried along by the flow.
  • These vortices like small tornadoes, release particles from the bottom and set them in motion; the flow carries them and in this way the second undermining mechanism is had.
  • the von Karman vortices form an important part of the turbulent wake caused by the presence of the structure or object within the flow.
  • the intensity of the action of this second mechanism is related to the behavior of the boundary layer, which is the fluid layer of small thickness that runs in contact with the structure or the submerged object. Said boundary layer tends to move while remaining in contact with the structure until the flow separation occurs, which consists in that the boundary layer is detached from the structure and is carried by the current.
  • a phenomenon known by the Fluid Mechanics is shown: the intensity of the von Karman vortices and the dimensions of the turbulent wake depend, equally with the remaining characteristics, on the location of points 16 of the perimeter of the structure 10 where the flow separation occurs; the farther down these points 16, the turbulent wake 17 will have smaller dimensions and its vortices will be less intense.
  • the flow separation points 16 are further downstream than in Fig. 2, so that the turbulent wake produced 17 is smaller and the vortices have less intensity and, therefore, produce less undermining My invention takes advantage of this effect, as will be seen later in this document.
  • the measures described which make up the main body of the current state of the art, have the objective of reinforcing the bottom susceptible to undermining or moving away from the phenomenon of undermining of the structure or object to be protected or displaced to a depth that responds more to a fear of failure than to an engineering, rational decision. That is, the state of the art tries, at great cost and without much success, to reduce the local undermining, without attacking the very cause of the phenomenon. Vulnerability statistics of structures submerged to the action of local undercutting show that the protection currently obtained is deficient and that there is an urgent need for a better solution.
  • the technique recommends measures such as the addition of anchors or fasteners to the bottom and burial at considerable depths, which represents strong costs.
  • the current state of the technique does not consider, in any of the cases mentioned, the control of the hydrodynamics responsible for the two main mechanisms that produce the undercut and which have already been described.
  • Bilanin Alan J., SYSTEM FOR ALLEVIATING SCOURING AROUND SUBMERGED STRUCTURES (US Patent 5,762,448, June 9, 1998).
  • the present invention attacks the problem of local undercutting from the source itself: it favorably modifies the flow close to the structure or the submerged object, in order to reduce the intensity and the effect of the two main undercutting mechanisms already described.
  • My invention consists of a mold 20 (Fig. 4) that allows to produce an artificial roughness, specially designed, on the surface of the structures and objects submerged in a current or flow and that are constructed by emptying.
  • Said roughness has a decisive influence on the hydrodynamic conditions causing the undercutting, since it reduces the secondary flow and the corresponding vortex in horseshoe, on the one hand, and also weakens the turbulent wake generated by the flow around said structures and objects, on the other.
  • the local undermining produced decreases, which translates into a greater security of the structure or of the submerged or buried object, in an extension of the useful life of said structure or object and in a saving in the corresponding costs.
  • the current state of the technique does not take into consideration the characteristics of the surface of the submerged structures; the general use is to give a smooth finish to said surface, in the case in which the structure is formed in a mold (as in the most frequent case, of structures made in concrete), and preserve the natural roughness of the material used, in other cases.
  • the artificial roughness produced by the present invention is of two specific types; Each of them has its own characteristics and acts particularly effectively against one of the two vortex generation mechanisms described above.
  • the types of artificial roughness and their ways of operating are:
  • Directional roughness 18 (Fig. 4 and Fig. 6) .- Acts effectively against the first undercut mechanism (horseshoe vortex). I recommend creating this type of artificial roughness at the edge or area of attack of the structure or submerged object (the area or face that is directed towards the direction from which the current or flow comes from), especially in the case of structures and objects in vertical position or close to it.
  • Said directional roughness should preferably consist of linear rough elements in the form of strips: striations (in bas-relief) or protruding edges (in relief). I recommend that the line of these strips be such that it meets one of the following two conditions, or a combination of both:
  • Non-directional roughness 19 (Fig. 4, Fig. 5 and Fig. 6) .- It is especially effective against the second undermining mechanism (von Karman vortices), although it also acts against the first mechanism (horseshoe vortex) if It is created on the edge or area of attack of the structure or submerged object. I recommend producing said non-directional artificial roughness on the submerged surface of the structure that does not belong to the edge or area of attack.
  • Fig. 5 shows the type of non-directional roughness; It consists of a set of rough rough elements 19 in bas-relief or in relief of shape, size and distribution such that they cause the laminar boundary layer (formed by particles that flow in an orderly manner), which moves in contact with the surface of the structure or of the structure. submerged object, it becomes turbulent (formed by particles that flow chaotically).
  • This transformation results in the separation of said boundary layer (Fig. 3) occurring at points 16 located further downstream than in the case of a smooth surface (Fig. 2), thus reducing the dimensions and The intensity of the turbulent wake 17 of the submerged structure 10, which produces less undercutting, as explained in the section referring to the state of the art.
  • U is the average flow velocity
  • D is the diameter of the cylindrical cell
  • v is the coefficient of kinematic viscosity of the liquid.
  • the second study was conducted in a rectangular section channel of 1.50 meters wide, with a flow rate that varied between 49.5 and 59.4 liters / second;
  • the bottom material was sand and its movement start speed was 0.22 meters / second.
  • Artificial roughness was created in cylindrical batteries of 0.10 meters in diameter;
  • the depth of flow varied from 0.12 meters to 0.20 meters.
  • the Fraud Number values varied between 0.14 and 0.27 and the Reynolds Number values, between 1, 7 X 10 4 and 2.7 X 10 4 .
  • Fig. 6 Submerged structure with directional artificial roughness and non-directional artificial roughness (perspective).
  • Fig. 4 shows the main features.
  • the mold to create the artificial roughness be made of a material such as rubber or a polymer, plastic or a similar material that is flexible and that is not excessively elastic (to preserve the shapes, proportions and distributions of the protrusions and of the bas-reliefs that will serve to create the artificial roughness).
  • the shape of the mold can be that of a layer or plate whose dimensions obey the following indications:
  • the mold can be used in at least two ways:
  • Fig. 4 and in Fig. 6 one of the possible lines of the linear rough elements is shown following the guidelines established in the detailed description of the invention; the stretch marks 18 shown in the figures are a family of elliptical curves whose minor axis is vertical and whose major axis is horizontal. You can draw these lines in other ways: arcs of circles, parabolas, non-regular curves, line segments, etc. The stripes can be replaced by specific rough elements aligned according to the mentioned lines; The description of the point rough elements appears later, in part 2, referring to the non-directional roughness.
  • the basic geometric characteristics that I recommend for this type of roughness are the following:
  • Stretch marks with a depth of 0.5 centimeters to 5 centimeters and a semicircular or rectangular cross section, with a width equal to twice the depth. I recommend a free space between stretch marks approximately equal to the depth. Such stretch marks, however, may have other cross-sectional shapes and other dimensions and proportions.
  • Stretch marks can be replaced by depressions or spaces between rough rough elements aligned according to the mentioned curves; The description of the point rough elements appears later, in part 2, referring to the non-directional roughness.
  • the mentioned edges may have other cross-sectional shapes and other dimensions and proportions.
  • the edges can be replaced by specific rough elements aligned according to the mentioned curves; The recommended description of the specific rough elements appears later, in part 2, referring to the non-directional roughness.
  • the area or area of attack of the structure or the submerged object is easily identifiable when the horizontal cross-section of the structure or the submerged object is rectangular or square, since it is the submerged area that faces the current.
  • the area of attack can be defined as the area vertically between the free surface of the water and the bottom and, horizontally, between two vertical lines drawn on the surface of the stack facing the flow, defined by two horizontal radii that form an angle of approximately 10 sexagesimal degrees to one side and another of the radius parallel to the direction of the Ia stream.
  • Shape and size of the point rough elements preferably, in the form of grooves (in bas-relief) or projections (in relief) of circular lines and semicircular cross-section.
  • Fig. 5 shows this geometry. I recommend that the outer diameter be 1 centimeter to 5 centimeters and the inner diameter, 0.6 centimeters to 3 centimeters, keeping between the outer and inner diameter a ratio of approximately 5/3.
  • These elements may also have other shapes, such as: spherical cap, cylinder, hub, etc. And also have other sizes. The proportions between the mentioned dimensions may also be different.
  • Distribution of the elements (Fig. 5): preferably, with three sticks; that is, in parallel rows and such that the elements of a row correspond to the spaces of the next row and thus form a network of equilateral triangles. I recommend that the free space between elements be approximately equal to the difference between the outer and inner diameters of the previous paragraph. Other distributions can also be used: rectangular, rhomboidal, irregular, etc.
  • Fig. 6 shows a submerged cylindrical structure in which my mold has created directional roughness 18 and non-directional roughness 19.
  • My invention can be used to increase security against local undermining and increase the useful life, as well as to reduce the costs of construction, maintenance or repair of structures and objects submerged in a current or flow.
  • These structures can be piles and stirrups of bridges, piles, columns, equipment and machinery supports, ducts and similar structures and objects.
  • Such objects may be supported, anchored, driven or buried at the bottom or on the banks of gullies or ravines or in river, lagoon, estuarine, coastal and marine environments susceptible to being undermined by both permanent and ephemeral natural currents, or in artificial conduits. .
  • the present invention can also be used to reduce the turbulent wake formed by structures and objects submerged in a flow and that are part of a hydraulic work, such as the columns and walls supporting gates, crossing structures and control , of the walls and columns in pumping tanks, etc.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Bridges Or Land Bridges (AREA)

Abstract

The invention relates to a mould for creating specially-designed artificial roughness (18, 19) that is intended for the surface of structures and objects (10) which are submerged in a flow (12) and which are supported by, or buried in a soil that is liable to scour, such as bridge piers and piles, ducts and other elements. The artificial roughness, which is created during the casting of the structures, reduces both the intensity of the secondary flow at the leading edge and the intensity of the wake turbulence, thereby reducing the depth and volume of local scouring that can affect said structures.

Description

MOLDE PARA CREAR RUGOSIDAD ARTIFICIAL CONTRA LA SOCAVACIÓN MOLD TO CREATE ARTIFICIAL RUGOSITY AGAINST SOCAVATION
DESCRIPCIÓNDESCRIPTION
CAMPO DE LA TÉCNICAFIELD OF THE TECHNIQUE
La presente invención se refiere a una mejora en Ia prevención de Ia socavación o erosión alrededor de estructuras y objetos sumergidos en una corriente o flujo y que son construidos por vaciado. Tales estructuras pueden ser pilas y estribos de puentes, pilotes, columnas, soportes de estructuras o de equipo o de máquinas, conductos y otros objetos. Las estructuras mencionadas y objetos similares pueden estar apoyados, anclados, hincados o enterrados en el lecho o fondo o en las márgenes de una cárcava o barranca, de un cuerpo de agua o de un conducto artificial o de un medio fluvial, lagunar, estuarino, costero o marino.The present invention relates to an improvement in the prevention of undermining or erosion around structures and objects submerged in a stream or flow and that are constructed by emptying. Such structures can be piles and stirrups of bridges, piles, columns, supports of structures or of equipment or of machines, conduits and other objects. The aforementioned structures and similar objects may be supported, anchored, driven or buried in the bed or bottom or in the margins of a gully or ravine, of a body of water or of an artificial conduit or of a river, lagoon, estuarine, Coastal or marine.
ESTADO DE LA TÉCNICASTATE OF THE TECHNIQUE
Un problema frecuente en el caso de las estructuras y de los objetos sumergidos en cuerpos de agua que tienen movimiento es Ia socavación local o erosión de material del fondo en el que se apoyan, inducida por Ia alteración de Ia corriente o flujo causada por Ia presencia de esas estructuras y objetos. Dicha alteración consiste en aumentos locales de Ia velocidad y en Ia aparición de flujos secundarios y de estelas con remolinos o vórtices, llamadas estelas turbulentas. La socavación local desprende material del fondo alrededor de las estructuras y objetos y puede disminuir el apoyo de los mismos, amenazando así a su estabilidad y a su seguridad y a las de Ia superestructura correspondiente, en su caso.A frequent problem in the case of structures and objects submerged in bodies of water that have movement is the local undercutting or erosion of bottom material on which they rest, induced by the alteration of the current or flow caused by the presence of those structures and objects. Said alteration consists of local increases in speed and in the appearance of secondary flows and stelae with eddies or vortices, called turbulent stelae. The local undermining releases material from the bottom around the structures and objects and can reduce their support, thus threatening their stability and safety and those of the corresponding superstructure, where appropriate.
A pesar del desarrollo técnico logrado a través de Ia investigación, tanto experimental como con ayuda de simulación numérica y con estudios de campo, realizada en innumerables instituciones de muchos países, y a pesar del interés de los organismos encargados de Ia infraestructura de comunicaciones terrestres y de las enormes cantidades de dinero invertido en Ia búsqueda de soluciones, Ia socavación es Ia causa principal de los colapsos de los puentes en todo el mundo. Un 60 % de esos desastres se debe a dicho fenómeno; por ello, hoy en día es un factor de primera importancia en el diseño de dichas estructuras y un reto técnico urgente aún por resolver (Refs. 1 , 2, 3, 4, 5, 6, 30) (Ver Lista de Referencias al final de ESTADO DE LA TÉCNICA).Despite the technical development achieved through research, both experimental and with the help of numerical simulation and with field studies, carried out in innumerable institutions in many countries, and despite the interest of the agencies in charge of the infrastructure of terrestrial communications and the enormous amounts of money invested in the search for solutions, the undermining is the main cause of the collapse of the bridges in all the world. 60% of these disasters are due to this phenomenon; Therefore, today it is a factor of first importance in the design of these structures and an urgent technical challenge still to be resolved (Refs. 1, 2, 3, 4, 5, 6, 30) (See List of References at the end STATE OF THE TECHNIQUE).
En el estado de Texas (Estados Unidos), que cuenta con 48.000 puentes y donde se construye entre 200 y 300 puentes al año, a un costo promedio de 500.000 dólares cada uno, colapsaron 1.000 puentes entre 1961 y 1991 ; en Estados Unidos, 18.000 puentes están considerados en estado crítico con respecto a Ia socavación (Ref. 5). El gran número de puentes existentes (más de 575.000 en Estados Unidos, más de 156.000 en el Reino Unido) (Refs. 7, 8, 9) da una indicación de Ia magnitud del problema, que tiene un impacto dramático en Ia economía. Los costos relacionados de manera directa con los colapsos de los puentes son siempre muy altos. Por ejemplo, aproximadamente un 19% de los fondos federales de emergencia de los Estados Unidos utilizados en el rubro de carreteras se emplea en Ia restauración de puentes; en el período 1980-1990, ello significó un promedio de 20 millones de dólares anuales (Ref. 3). Se debe sumar a los costos anteriores los costos indirectos resultantes de las graves afectaciones a las vías de comunicación y a los trastornos en muchas actividades; tales costos pueden ser aún más altos que los costos directos: Ia Federal Highway Administration de los Estados Unidos estima que dichos costos indirectos pueden ser cinco veces mayores que los directos (Ref. 30). También hay un costo de prevención de esos desastres: en Estados Unidos, se ha gastado unos 15 millones de dólares en los últimos 8 años en investigación acerca de fallas de puentes, principalmente por socavación en fondo arenoso (Ref. 5).In the state of Texas (United States), which has 48,000 bridges and where 200 to 300 bridges are built per year, at an average cost of $ 500,000 each, 1,000 bridges collapsed between 1961 and 1991; In the United States, 18,000 bridges are considered in critical condition with respect to undercutting (Ref. 5). The large number of existing bridges (more than 575,000 in the United States, more than 156,000 in the United Kingdom) (Refs. 7, 8, 9) gives an indication of the magnitude of the problem, which has a dramatic impact on the economy. The costs directly related to the collapse of the bridges are always very high. For example, approximately 19% of the federal emergency funds of the United States used in the road sector are used in the restoration of bridges; in the period 1980-1990, this meant an average of 20 million dollars annually (Ref. 3). The indirect costs resulting from the serious effects on communication channels and disorders in many activities must be added to the above costs; such costs may be even higher than direct costs: the Federal Highway Administration of the United States estimates that said indirect costs may be five times higher than direct costs (Ref. 30). There is also a cost of preventing these disasters: in the United States, about 15 million dollars have been spent in the last 8 years on research on bridge failures, mainly due to undercutting in sandy bottoms (Ref. 5).
Las fallas de puentes también implican un riesgo importante para Ia seguridad pública: se han perdido vidas humanas en esos desastres. El colapso de un puente por socavación inicia generalmente con Ia pérdida de apoyo de una o más pilas, que son las columnas intermedias que sostienen a Ia superestructura del puente. También puede fallar uno de los estribos, que son los apoyos de los extremos del puente, donde éste descansa sobre las márgenes del cauce.Bridge failures also imply a significant risk to public safety: human lives have been lost in these disasters. The collapse of a bridge by undermining generally begins with the loss of support of one or more piles, which are the intermediate columns that support the superstructure of the bridge. It can also fail one of the stirrups, which are the supports of the ends of the bridge, where it rests on the banks of the channel.
Otros ejemplos de estructuras susceptibles a daño por Ia socavación local son los pilotes, las columnas, los soportes de estructuras o de equipo o de máquinas, las tuberías y otros conductos y estructuras y objetos similares, apoyados, anclados, hincados o enterrados en el lecho o fondo o en las •márgenes de una cárcava o barranca, de un cuerpo de agua o de un conducto artificial o de un medio fluvial, lagunar, estuarino, costero o marino.Other examples of structures susceptible to damage by local undermining are the piles, the columns, the supports of structures or equipment or machines, the pipes and other ducts and similar structures and objects, supported, anchored, driven or buried in the bed or bottom or on the • margins of a gully or ravine, of a body of water or of an artificial conduit or of a river, lagoon, estuarine, coastal or marine environment.
La socavación local es producida por un flujo turbulento complejo, que resulta principalmente de Ia acción de dos mecanismos independientes, bien conocidos y estudiados por múltiples investigadores. Enseguida se presenta una breve explicación de esas dos diferentes causas del fenómeno, conocimiento que forma parte del estado de Ia técnica y que constituye Ia base de Ia presente invención.Local undercutting is produced by a complex turbulent flow, which results mainly from the action of two independent mechanisms, well known and studied by multiple researchers. Below is a brief explanation of these two different causes of the phenomenon, knowledge that is part of the state of the art and that constitutes the basis of the present invention.
a). Primer mecanismo: vórtice en herradura. La Fig. 1 muestra una estructura u objeto sumergido de forma cilindrica 10, apoyada en un fondo socavable o erosionable 11. El flujo 12 que incide contra el borde o zona de ataque, que es Ia cara o zona de Ia estructura que está dirigida hacia Ia dirección de donde proviene Ia corriente o flujo, es desviado hacia abajo; se genera así un flujo secundario que al chocar contra el fondo 11 produce el llamado vórtice en herradura 13. Este vórtice rodea a Ia estructura o al objeto sumergido y se propaga hacia aguas abajo, desprendiendo material del fondo 11 alrededor de dicha estructura; ese material es entonces arrastrado por Ia corriente, formándose así el foso de socavación 15.to). First mechanism: horseshoe vortex. Fig. 1 shows a structure or object submerged in a cylindrical shape 10, supported by an undercut or erodible bottom 11. The flow 12 that strikes the edge or area of attack, which is the face or area of the structure that is directed towards The direction from which the current or flow comes is diverted downwards; A secondary flow is thus generated which, when hitting the bottom 11, produces the so-called horseshoe vortex 13. This vortex surrounds the structure or the submerged object and propagates downstream, releasing material from the bottom 11 around said structure; that material is then dragged by the current, thus forming the undercut pit 15.
El vórtice en herradura es especialmente importante en el caso de estructuras sumergidas en posición vertical o cercana a ella.The horseshoe vortex is especially important in the case of submerged structures in a vertical position or close to it.
b). Segundo mecanismo: vórtices de von Karman (Fig. 1).- El flujo que rodea a Ia estructura o al objeto sumergido 10 produce vórtices 14 denominados vórtices de von Karman. Dichos vórtices tienden a formarse periódicamente y alternadamente de un lado y del otro de Ia estructura u objeto sumergido y son arrastrados por el flujo. Dichos vórtices, como pequeños tornados, desprenden partículas del fondo y las ponen en movimiento; el flujo las transporta y se tiene de esta manera el segundo mecanismo de socavación. Los vórtices de von Karman forman parte importante de Ia estela turbulenta provocada por Ia presencia de Ia estructura o del objeto dentro del flujo.b). Second mechanism: von Karman vortices (Fig. 1) .- The flow surrounding the structure or the submerged object 10 produces vortices 14 called vortices of von Karman Said vortices tend to form periodically and alternately on one side and the other of the submerged structure or object and are carried along by the flow. These vortices, like small tornadoes, release particles from the bottom and set them in motion; the flow carries them and in this way the second undermining mechanism is had. The von Karman vortices form an important part of the turbulent wake caused by the presence of the structure or object within the flow.
La intensidad de Ia acción de este segundo mecanismo está relacionada con el comportamiento de Ia capa límite, que es Ia capa fluida de pequeño espesor que escurre en contacto con Ia estructura o el objeto sumergido. Dicha capa límite tiende a desplazarse permaneciendo en contacto con Ia estructura hasta que se presenta Ia separación de flujo, que consiste en que Ia capa límite se desprende de Ia estructura y es arrastrada por Ia corriente. En las Figs. 2 y 3 se muestra un fenómeno conocido por Ia Mecánica de Fluidos: Ia intensidad de los vórtices de von Karman y las dimensiones de Ia estela turbulenta dependen, a igualdad de las restantes características, de Ia ubicación de los puntos 16 del perímetro de Ia estructura 10 donde ocurre Ia separación de flujo; entre más alejado hacia aguas abajo estén esos puntos 16, Ia estela turbulenta 17 tendrá menores dimensiones y sus vórtices serán menos intensos. En Ia Fig. 3, los puntos de separación de flujo 16 se encuentran más hacia aguas abajo que en Ia Fig. 2, por Io que Ia estela turbulenta producida 17 es más pequeña y los vórtices tienen menor intensidad y, por Io tanto, producen menos socavación. Mi invención aprovecha este efecto, como se verá más adelante en este documento.The intensity of the action of this second mechanism is related to the behavior of the boundary layer, which is the fluid layer of small thickness that runs in contact with the structure or the submerged object. Said boundary layer tends to move while remaining in contact with the structure until the flow separation occurs, which consists in that the boundary layer is detached from the structure and is carried by the current. In Figs. 2 and 3 a phenomenon known by the Fluid Mechanics is shown: the intensity of the von Karman vortices and the dimensions of the turbulent wake depend, equally with the remaining characteristics, on the location of points 16 of the perimeter of the structure 10 where the flow separation occurs; the farther down these points 16, the turbulent wake 17 will have smaller dimensions and its vortices will be less intense. In Fig. 3, the flow separation points 16 are further downstream than in Fig. 2, so that the turbulent wake produced 17 is smaller and the vortices have less intensity and, therefore, produce less undermining My invention takes advantage of this effect, as will be seen later in this document.
Si Ia profundidad del foso de socavación 15, determinada básicamente por Ia adición de los efectos de los dos mecanismos descritos, rebasa cierta magnitud, disminuye el apoyo de Ia estructura y hay riesgo para Ia seguridad de Ia misma.If the depth of the undercutting pit 15, basically determined by the addition of the effects of the two mechanisms described, exceeds a certain magnitude, the support of the structure decreases and there is a risk to its safety.
En el caso de las estructuras y de los objetos enterrados totalmente en el fondo, Ia socavación, una vez que los pone parcialmente al descubierto, se acelera por los vórtices inducidos por las propias estructuras y objetos y expone a éstos a daños, por Io que pueden requerir mantenimiento frecuente, y en ocasiones, reparación o reconstrucción. Por lo antes mencionado, en todos los casos de estructuras y objetos sumergidos en un medio líquido con movimiento o enterrados en el fondo respectivo es conveniente reducir Ia vorticidad causante de Ia socavación, para incrementar Ia seguridad de las estructuras o de los objetos involucrados, prolongar su vida útil y reducir los costos de mantenimiento o de reparación, en su caso.In the case of structures and objects buried completely at the bottom, the undercutting, once partially exposed, is accelerated by the vortices induced by the structures and objects themselves and exposes them to damage, so They may require frequent maintenance, and sometimes repair or reconstruction. For the aforementioned, in all cases of structures and objects submerged in a liquid medium with movement or buried in the respective bottom, it is convenient to reduce the vorticity causing the undercutting, to increase the safety of the structures or objects involved, prolong its useful life and reduce maintenance or repair costs, if applicable.
El estado actual de Ia técnica consiste en enfrentar al problema con tres tipos principales de medidas dirigidas a reducir los efectos de Ia socavación alrededor de Ia estructura o del objeto sumergido:The current state of the technique consists in facing the problem with three main types of measures aimed at reducing the effects of the undercutting around the structure or the submerged object:
1. La protección o recubrimiento del fondo o del cauce en Ia zona próxima a Ia estructura o al objeto sumergido, utilizando uno o más de los siguientes recursos: roca, estructuras monolíticas de concreto (hormigón) precoladas y coladas en el lugar, concreto triturado, terraplenes de piedras (pedraplenes), colchones o carpetas de varios tipos constituidos por elementos pesados tales como bolsas hechas de mallas de plástico o geotextiles rellenas de concreto o de piedras, capas de piedras de tamaños determinados retenidas y separadas por mallas de geotextiles, jaulas metálicas rellenas de piedras (gaviones), bloques de concreto unidos entre sí por cables de acero, columnas enterradas de llantas de desecho unidas por elementos metálicos, inyecciones de cemento fluido en el fondo, debajo y alrededor de una estructura sumergida y mezclado de dicho cemento con el suelo con ayuda de máquinas para solidificar Ia zona de apoyo, Ia generación de corrientes ascendentes por medio de pequeñas máquinas hidráulicas para contrarrestar el flujo secundario descendente, y otros recursos (Refs. 4, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27).1. The protection or covering of the bottom or the channel in the area near the structure or the submerged object, using one or more of the following resources: rock, monolithic concrete structures (concrete) precooked and cast in place, crushed concrete , stone embankments (pedraplens), mattresses or folders of various types consisting of heavy elements such as bags made of plastic or geotextile meshes filled with concrete or stones, layers of stones of certain sizes retained and separated by geotextile meshes, cages metal filled with stones (gabions), concrete blocks joined together by steel cables, buried columns of scrap tires joined by metal elements, injections of fluid cement in the bottom, under and around a submerged and mixed structure of said cement with the ground with the help of machines to solidify the support area, the generation of updrafts by means of pe you want hydraulic machines to counteract the downward secondary flow, and other resources (Refs. 4, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27).
2. La incorporación a Ia estructura o al objeto sumergido (o cerca de él) de algunos apéndices o elementos (generalmente, de concreto armado) cuya forma ayuda a desviar al flujo alejándolo de Ia estructura u objeto sumergido o cuya posición y forma tienden a alejar a Ia socavación con respecto a Ia estructura u objeto sumergido, tales como espolones, deflectores de flujo en "V", bordes o extremos semicirculares o triangulares, losas de protección, collares, pilotes de sacrificio y otros elementos (Refs. 4, 9, 10, 28, 29).2. The incorporation into the structure or the submerged object (or near it) of some appendices or elements (generally, of reinforced concrete) whose form helps to divert the flow away from the submerged structure or object or whose position and shape tend to away from undercutting with respect to the submerged structure or object, such as spurs, "V" flow deflectors, edges or ends semicircular or triangular, protection slabs, necklaces, slaughter piles and other elements (Refs. 4, 9, 10, 28, 29).
3. La construcción de Ia cimentación de las estructuras a profundidades considerables, mayores que las de socavación estimadas por medio de las fórmulas de cálculo disponibles. La razón es que tales fórmulas arrojan resultados poco confiables; sus márgenes de error son generalmente grandes. Además, Ia aplicación de las mismas es limitada porque no consideran los casos de flujos complejos, como son los que incluyen oleaje y corrientes, no toman en cuenta características geotécnicas complejas del fondo y sólo se aplican a formas simples de pilas.3. The construction of the foundation of the structures at considerable depths, greater than those of undercutting estimated by means of the available calculation formulas. The reason is that such formulas yield unreliable results; Their margins of error are generally large. In addition, their application is limited because they do not consider cases of complex flows, such as those that include waves and currents, do not take into account complex geotechnical characteristics of the fund and only apply to simple battery forms.
La aplicación de esos tres tipos de medidas siempre es costosa: requiere tiempo y volumen adicionales de obra, implica el uso de elementos y de materiales cuya preparación, transporte y colocación requieren personal, equipo y maquinaria pesada y técnicas especiales. La presencia de oleaje o de alta velocidad del flujo complica las maniobras correspondientes. Además, estas medidas generalmente requieren mantenimiento, Io que incrementa su costo.The application of these three types of measures is always expensive: it requires additional time and volume of work, it implies the use of elements and materials whose preparation, transport and placement require personnel, equipment and heavy machinery and special techniques. The presence of swell or high flow velocity complicates the corresponding maneuvers. In addition, these measures generally require maintenance, which increases their cost.
Desde el punto de vista funcional, las medidas descritas, que conforman el cuerpo principal del estado actual de Ia técnica, tienen como objetivo reforzar el fondo susceptible de socavación o alejar al fenómeno de socavación de Ia estructura u objeto a proteger o desplantar ésta a una profundidad que responde más a un temor de falla que a una decisión ingenieril, racional. Es decir, el estado de Ia técnica intenta, a gran costo y sin mucho éxito, reducir Ia socavación local, sin atacar a Ia causa misma del fenómeno. Las estadísticas de vulnerabilidad de las estructuras sumergidas a Ia acción de Ia socavación local muestran que Ia protección obtenida actualmente es deficiente y que hay una urgente necesidad de una mejor solución.From the functional point of view, the measures described, which make up the main body of the current state of the art, have the objective of reinforcing the bottom susceptible to undermining or moving away from the phenomenon of undermining of the structure or object to be protected or displaced to a depth that responds more to a fear of failure than to an engineering, rational decision. That is, the state of the art tries, at great cost and without much success, to reduce the local undermining, without attacking the very cause of the phenomenon. Vulnerability statistics of structures submerged to the action of local undercutting show that the protection currently obtained is deficient and that there is an urgent need for a better solution.
En el caso de las estructuras y de los objetos enterrados en el fondo de una masa líquida en Ia que hay corrientes, como las tuberías y conductos que cruzan corrientes naturales o zonas lagunares, estuarinas, costeras o marinas, el estado deIn the case of structures and objects buried at the bottom of a liquid mass in which there are currents, such as pipes and ducts that cross natural currents or lagoon, estuarine, coastal or marine areas, the state of
Ia técnica recomienda medidas como Ia adición de anclas o sujeciones al fondo y el enterramiento a profundidades considerables, Io que representa fuertes costos. El estado actual de Ia técnica no considera, en ninguno de los casos citados, el control de Ia hidrodinámica responsable de los dos mecanismos principales que producen Ia socavación y que ya fueron descritos.The technique recommends measures such as the addition of anchors or fasteners to the bottom and burial at considerable depths, which represents strong costs. The current state of the technique does not consider, in any of the cases mentioned, the control of the hydrodynamics responsible for the two main mechanisms that produce the undercut and which have already been described.
Nota: Esta invención tiene las mismas bases técnicas que Ia que he tituladoNote: This invention has the same technical basis as the one I have titled
RECUBRIMIENTO CONTRA SOCAVACIÓN Y FUERZA DE ARRASTRE EN ESTRUCTURAS, con referencia al expediente del solicitante 12136REC, que se refiere a una aplicación diferente y que presento simultáneamente con ésta.COVERAGE AGAINST SOCAVATION AND DRAWING FORCE IN STRUCTURES, with reference to the applicant's file 12136REC, which refers to a different application and that I present simultaneously with it.
LISTA DE REFERENCIAS DEL ESTADO DE LA TÉCNICALIST OF REFERENCES OF THE STATE OF THE TECHNIQUE
1. Jones, J. Sterling, Hydraulics Testing of Wilson Bridge Designs, Public Roads, Federal Highway Administration, U. S. Department of Transportation, http://www.tfhrc.gov/pubrds/maraprOO/hydra.htm1. Jones, J. Sterling, Hydraulics Testing of Wilson Bridge Designs, Public Roads, Federal Highway Administration, U. S. Department of Transportation, http://www.tfhrc.gov/pubrds/maraprOO/hydra.htm
2. Khotyari, U. C; Ranga Raju, K. G., Scour Around Spur Dikes and Bridge Abutments, Journal of Hydraulic Research, VoI. 39, 2001, No. 4.2. Khotyari, U. C; Ranga Raju, K. G., Scour Around Spur Dikes and Bridge Abutments, Journal of Hydraulic Research, VoI. 39, 2001, No. 4.
3. U. S. Geological Survey, Bridge Scour: It's Not Just Water Under the Bridge, http://www.usgs.gov/2001openhouse/exhibits/35-bridgescour.html3. U. S. Geological Survey, Bridge Scour: It's Not Just Water Under the Bridge, http://www.usgs.gov/2001openhouse/exhibits/35-bridgescour.html
4. Parker, Gary; Voigt, Rick, National Cooperative Highway Research Program, (NCHRP Project 24-7(2)), Countermeasures to Protect Bridge Piers from4. Parker, Gary; Voigt, Rick, National Cooperative Highway Research Program, (NCHRP Project 24-7 (2)), Countermeasures to Protect Bridge Piers from
Scour, http://www4.trb.org/trb/crp.nsf/AII+Projects/NCHRP+24-07Scour, http://www4.trb.org/trb/crp.nsf/AII+Projects/NCHRP+24-07
5. Briaud, Jean-Louis, SRICOS Sheds Light on Bridge Scour Problems, Texas Transportation Institute, http://tti.tamu.edu/product/ror/sricos.stm5. Briaud, Jean-Louis, SRICOS Sheds Light on Bridge Scour Problems, Texas Transportation Institute, http://tti.tamu.edu/product/ror/sricos.stm
6. Bell, Brian, Structural Integrity Monitoring Network (SIMoNET), Bridge Scour - the challenge to the SIM industry, http://www.ojpweb.co.uk/simonet/forum/viewtopic.php?t=116. Bell, Brian, Structural Integrity Monitoring Network (SIMoNET), Bridge Scour - the challenge to the SIM industry, http://www.ojpweb.co.uk/simonet/forum/viewtopic.php?t=11
7. Weissmann, José; Haas, Cari, Bridge Foundation Scour Monitoring, The7. Weissmann, José; Haas, Cari, Bridge Foundation Scour Monitoring, The
University of Texas, http://www.eng.utsa.edu/~josew/Scour.htmUniversity of Texas, http://www.eng.utsa.edu/~josew/Scour.htm
8. Kamil H. M. AIi; Othman Karim, Simulation of Flow Around Piers, Journal of Hydraulic Research, VoI. 40, 2002, No. 2.8. Kamil H. M. AIi; Othman Karim, Simulation of Flow Around Piers, Journal of Hydraulic Research, VoI. 40, 2002, No. 2.
9. U. S. Department of Transportation, Federal Highway Administration, Summary of 1998 Scanning Review of European Practice for Bridge Scour and Stream Instability Countermeasures, http://www.fhwa.dot.gov/engineering/hydraulics/pubs/scanningreview1998/sca ntxt.cfm 10. Kim, Ung Yong; Ahn, Sang Jin, Scour Countermeasure around Bridge Piers using Protection Devices, http://kfki.baw.de/conferences/ICHE/2000- Seoul/pdf/251/PAP_263.PDF9. US Department of Transportation, Federal Highway Administration, Summary of 1998 Scanning Review of European Practice for Bridge Scour and Stream Instability Countermeasures, http://www.fhwa.dot.gov/engineering/hydraulics/pubs/scanningreview1998/sca ntxt. cfm 10. Kim, Ung Yong; Ahn, Sang Jin, Scour Countermeasure around Bridge Piers using Protection Devices, http://kfki.baw.de/conferences/ICHE/2000- Seoul / pdf / 251 / PAP_263.PDF
11. St. Anthony FaIIs Laboratory, University of Minnesota, River Engineering at SAFL, http://www.safl.umn.edu/research/applied/re/index.html 12. Porraz Lando, Mauricio José, FORMAS MODULARES PARA FABRICAR11. St. Anthony FaIIs Laboratory, University of Minnesota, River Engineering at SAFL, http://www.safl.umn.edu/research/applied/re/index.html 12. Porraz Lando, Mauricio José, MODULAR FORMS TO MANUFACTURE
RECUBRIMIENTOS ARTICULADOS DE ESPESOR, FILTRACIÓN Y RUGOSIDAD CONTROLADA (Patente MX 204504, Octubre 4, 2001).ARTICULATED COATINGS OF THICKNESS, FILTRATION AND CONTROLLED RUGOSITY (Patent MX 204504, October 4, 2001).
13. Porraz Jiménez, Mauricio, MEJORAS EN ELEMENTOS CONTENEDORES MIXTOS PLÁSTICO-TEXTILES PARA SER LLENADOS CON13. Porraz Jiménez, Mauricio, IMPROVEMENTS IN MIXED PLASTIC-TEXTILE CONTAINER ELEMENTS TO BE FILLED WITH
ARENA U OTROS MATERIALES GRANULARES O NO PARA CONSTRUCCIONES MARÍTIMAS Y ACUÁTICAS (Patente MX 163867, Junio 29, 1992).SAND OR OTHER GRANULAR MATERIALS OR NOT FOR MARITIME AND AQUATIC CONSTRUCTIONS (MX Patent 163867, June 29, 1992).
14. González Herrera, Rafael, MEJORAS EN PROCEDIMIENTO PARA LA COLOCACIÓN DE FAJINAS BAJO EL AGUA EN DESPLANTES DE ESCOLLERAS,14. González Herrera, Rafael, IMPROVEMENTS IN PROCEDURE FOR PLACEMENT OF FAJINAS UNDER WATER IN SCHOOL DISPLACEMENTS,
ROMPEOLAS O ESTRUCTURAS SIMILARES (Patente MX 167267, Marzo 12, 1993).BREAKERS OR SIMILAR STRUCTURES (Patent MX 167267, March 12, 1993).
15. Yoshino, Masato; Ishikawa.Yoshikazu, MATERIAL AND CONSTRUCTION METHOD OF PREVENTION OF SCOUR FOR THE UNDERWATER STRUCTURE15. Yoshino, Masato; Ishikawa.Yoshikazu, MATERIAL AND CONSTRUCTION METHOD OF PREVENTION OF SCOUR FOR THE UNDERWATER STRUCTURE
(Patente US 6,305,876 B1 , Octubre 23, 2001).(US Patent 6,305,876 B1, October 23, 2001).
16. Bilanin, Alan J., SYSTEM FOR ALLEVIATING SCOURING AROUND SUBMERGED STRUCTURES (Patente US 5,762,448, Junio 9, 1998).16. Bilanin, Alan J., SYSTEM FOR ALLEVIATING SCOURING AROUND SUBMERGED STRUCTURES (US Patent 5,762,448, June 9, 1998).
17. Yasuhiro, Murakami, SCOUR PREVENTIVE MATERIAL (Patente JP 2000319842, Noviembre 21 , 2000).17. Yasuhiro, Murakami, SCOUR PREVENTIVE MATERIAL (JP Patent 2000319842, November 21, 2000).
18. Naoki, Noguchi et al., PREVENTING METHOD FOR SCOUR (Patente JP 5604601 1 , Abril 27, 1981).18. Naoki, Noguchi et al., PREVENTING METHOD FOR SCOUR (JP Patent 5604601 1, April 27, 1981).
19. Yasuhiro, Iwasaki, PREVENTION OF SCOURING OF BOTTOM-LANDING TYPE MARINE STRUCTURE (Patente JP 58185811 , Octubre 29, 1983).19. Yasuhiro, Iwasaki, PREVENTION OF SCOURING OF BOTTOM-LANDING TYPE MARINE STRUCTURE (JP Patent 58185811, October 29, 1983).
20. Mamoru, Takasaki et al., SCOURING-PREVENTING DEVICE (Patente JP20. Mamoru, Takasaki et al., SCOURING-PREVENTING DEVICE (JP Patent
61277708, Diciembre 8, 1976).61277708, December 8, 1976).
21. Matsuhei; Ogawa, SCOURING PREVENTION WORK FOR UNDERWATER STRUCTURE (Patente JP 61242209, Octubre 28, 1986).21. Matsuhei; Ogawa, SCOURING PREVENTION WORK FOR UNDERWATER STRUCTURE (JP 61242209, October 28, 1986).
22. Hitoshi, Hatano, METHOD OF PREVENTING SCOURING OF UNDERWATER STRUCTURE (Patente JP 61134409, Junio 21 , 1986).22. Hitoshi, Hatano, METHOD OF PREVENTING SCOURING OF UNDERWATER STRUCTURE (JP 61134409, June 21, 1986).
23. Larsen Ole, APPARATUS FOR PREVENTING AND REDUCING SCOURS IN A BED SUPPORTING A BODY OF WATER (Patente GB 1383012, Febrero 5,23. Larsen Ole, APPARATUS FOR PREVENTING AND REDUCING SCOURS IN A BED SUPPORTING A BODY OF WATER (Patent GB 1383012, February 5,
1975). 24. Texaco Development Corp., ARTICULATED ANTI-SCOUR MAT FOR MARINE STRUCTURES (Patente GB 1472486, Mayo 4, 1977). 25. Lee, Keun-Hee, METHOD FOR CONSTRUCTING SCOUR PROTECTION1975). 24. Texaco Development Corp., ARTICULATED ANTI-SCOUR MAT FOR MARINE STRUCTURES (Patent GB 1472486, May 4, 1977). 25. Lee, Keun-Hee, METHOD FOR CONSTRUCTING SCOUR PROTECTION
OF BRIDGEAND STABILIZATION OF STREAM BED USING BLOCK MA T (Solicitud de Patente Internacional PCT/KR01/01823, Octubre 26, 2001).OF BRIDGEAND STABILIZATION OF STREAM BED USING BLOCK MA T (International Patent Application PCT / KR01 / 01823, October 26, 2001).
26. Larsen, Ole Fjord, APPARATUS FOR PREVENTING EROSIÓN OF THE SEABED IN FRONT OF HYDRAULIC STRUCTURES (Patente US 4,114,394, Marzo26. Larsen, Ole Fjord, APPARATUS FOR PREVENTING EROSION OF THE SEABED IN FRONT OF HYDRAULIC STRUCTURES (US Patent 4,114,394, March
8, 1977).8, 1977).
27. Kazuo, Ishino, SCOUR PREVENTING CONSTRUCTION METHOD (Patente JP 2000144675, Mayo 26, 2000).27. Kazuo, Ishino, SCOUR PREVENTING CONSTRUCTION METHOD (JP Patent 2000144675, May 26, 2000).
28. U. S. Federal Emergency Management Agency, Flood Handhook, Chapter 3: Bridges, D. Scour (Piers & Ahutments), www.conservationtech.com/FEMA-WEB/FEMA-subweb-flood/01-06-FLOOD/3- Bridges/D. Scour. htm28. US Federal Emergency Management Agency, Flood Handhook, Chapter 3: Bridges, D. Scour (Piers & Ahutments), www.conservationtech.com/FEMA-WEB/FEMA-subweb-flood/01-06-FLOOD/3- Bridges / D. Scour htm
29. Hadfield, A. C; Melville, B. W. Use of Sacrificial Piles as Pier Scour Countermeasures. Technical Note, Journal of Hydraulic Engineering, Volume 125, No. 11 , 1999, American Society of Civil Engineers. 30. Annandale, George W.; Melville, Bruce; Chiew, Yee-Meng, SCOUR CASE29. Hadfield, A. C; Melville, B. W. Use of Sacrificial Piles as Pier Scour Countermeasures. Technical Note, Journal of Hydraulic Engineering, Volume 125, No. 11, 1999, American Society of Civil Engineers. 30. Annandale, George W .; Melville, Bruce; Chiew, Yee-Meng, SCOUR CASE
STUDIES, Mitteilungsblatt der Bundesanstalt für Wasserbau Nr. 85 (2002) (Boletín Informativo No. 85 (2002) del Instituto Federal de Ingeniería e Investigación de Ríos y Canales (Alemania)).STUDIES, Mitteilungsblatt der Bundesanstalt für Wasserbau Nr. 85 (2002) (Information Bulletin No. 85 (2002) of the Federal Institute of Engineering and Research of Rivers and Canals (Germany)).
DESCRIPCIÓN DETALLADA DE LA INVENCIÓNDETAILED DESCRIPTION OF THE INVENTION
La presente invención ataca al problema de Ia socavación local desde el origen mismo: modifica favorablemente al flujo próximo a Ia estructura o al objeto sumergido, a fin de reducir Ia intensidad y el efecto de los dos mecanismos principales de socavación ya descritos.The present invention attacks the problem of local undercutting from the source itself: it favorably modifies the flow close to the structure or the submerged object, in order to reduce the intensity and the effect of the two main undercutting mechanisms already described.
Mi invención consiste en un molde 20 (Fig. 4) que permite producir una rugosidad artificial, especialmente diseñada, en Ia superficie de las estructuras y objetos sumergidos en una corriente o flujo y que son construidos por vaciado. Dicha rugosidad tiene una influencia decisiva en las condiciones hidrodinámicas causantes de Ia socavación, ya que reduce el flujo secundario y el correspondiente vórtice en herradura, por un lado, y también debilita a Ia estela turbulenta generada por el flujo alrededor de dichas estructuras y objetos, por el otro. Como resultado, disminuye Ia socavación local producida, Io que se traduce en una mayor seguridad de Ia estructura o del objeto sumergido o enterrado, en una prolongación de Ia vida útil de dicha estructura u objeto y en un ahorro en los costos correspondientes.My invention consists of a mold 20 (Fig. 4) that allows to produce an artificial roughness, specially designed, on the surface of the structures and objects submerged in a current or flow and that are constructed by emptying. Said roughness has a decisive influence on the hydrodynamic conditions causing the undercutting, since it reduces the secondary flow and the corresponding vortex in horseshoe, on the one hand, and also weakens the turbulent wake generated by the flow around said structures and objects, on the other. As a result, the local undermining produced decreases, which translates into a greater security of the structure or of the submerged or buried object, in an extension of the useful life of said structure or object and in a saving in the corresponding costs.
El estado actual de Ia técnica no toma en consideración a las características de Ia superficie de las estructuras sumergidas; el uso general es dar un acabado liso a dicha superficie, en el caso en el que Ia estructura es formada en un molde (como en el caso más frecuente, de estructuras hechas en concreto), y conservar Ia rugosidad natural del material utilizado, en otros casos.The current state of the technique does not take into consideration the characteristics of the surface of the submerged structures; the general use is to give a smooth finish to said surface, in the case in which the structure is formed in a mold (as in the most frequent case, of structures made in concrete), and preserve the natural roughness of the material used, in other cases.
Los fundamentos hidrodinámicos en los que se basa mi invención pertenecen al estado de Ia técnica de Ia Mecánica de Fluidos; su exposición se inició en el apartado de Estado de Ia Técnica y será ampliada más adelante.The hydrodynamic foundations on which my invention is based belong to the state of the art of Fluid Mechanics; His presentation began in the State of the Technical section and will be expanded later.
La rugosidad artificial producida por Ia presente invención es de dos tipos específicos; cada uno de ellos tiene sus propias características y actúa de manera especialmente eficaz contra uno de los dos mecanismos de generación de vórtices descritos más arriba. Los tipos de rugosidad artificial y sus formas de operar son:The artificial roughness produced by the present invention is of two specific types; Each of them has its own characteristics and acts particularly effectively against one of the two vortex generation mechanisms described above. The types of artificial roughness and their ways of operating are:
1. Rugosidad direccional 18 (Fig. 4 y Fig. 6).- Actúa eficazmente contra el primer mecanismo de socavación (vórtice en herradura). Recomiendo crear este tipo de rugosidad artificial en el borde o área de ataque de Ia estructura o del objeto sumergido (Ia zona o cara que está dirigida hacia Ia dirección de donde proviene Ia corriente o flujo), especialmente en el caso de estructuras y objetos en posición vertical o cercana a ella. Dicha rugosidad direccional debe estar constituida preferentemente por elementos rugosos lineales en forma de franjas: estrías (en bajorrelieve) o bordes salientes (en altorrelieve). Recomiendo que el trazo de dichas franjas sea tal que cumpla con una de las dos condiciones siguientes, o con una combinación de ambas:1. Directional roughness 18 (Fig. 4 and Fig. 6) .- Acts effectively against the first undercut mechanism (horseshoe vortex). I recommend creating this type of artificial roughness at the edge or area of attack of the structure or submerged object (the area or face that is directed towards the direction from which the current or flow comes from), especially in the case of structures and objects in vertical position or close to it. Said directional roughness should preferably consist of linear rough elements in the form of strips: striations (in bas-relief) or protruding edges (in relief). I recommend that the line of these strips be such that it meets one of the following two conditions, or a combination of both:
a). Que guíe al flujo secundario, que se dirige hacia el pie de Ia estructura u objeto sumergido y que escurre en las proximidades del área de ataque, desviándolo, de preferencia gradualmente, de Ia dirección vertical descendente (en Ia parte superior) hacia Ia dirección horizontal (en Ia parte inferior) de manera que dicho flujo secundario se comporte de una o de las dos formas siguientes:to). To guide the secondary flow, which is directed towards the foot of the submerged structure or object and that runs in the vicinity of the area of attack, deviating it, preferably gradually, from the descending vertical direction (in the upper part) towards the horizontal direction (in the lower part) so that said secondary flow behaves in one or both of the following ways:
a1). Que rodee por ambos costados a Ia estructura u objeto a proteger y se incorpore a Ia corriente sin llegar al fondo al pie de dicha estructura u objeto sumergido;a1). That surrounds on both sides the structure or object to be protected and is incorporated into the current without reaching the bottom at the bottom of said structure or submerged object;
a2). Que sus líneas de flujo choquen entre sí, perdiendo así energía dinámica.a2). That their flow lines collide with each other, thus losing dynamic energy.
b). Que provoque Ia formación de vórtices a Io largo del recorrido de las líneas de flujo; dichos vórtices restan energía al flujo secundario y tienden a ser arrastrados por Ia corriente antes de llegar al fondo.b). That causes the formation of vortices along the path of the flow lines; said vortices subtract energy from the secondary flow and tend to be carried by the current before reaching the bottom.
En ambos casos disminuye Ia magnitud del flujo secundario que incide en el fondo y, por tanto, se debilita al vórtice en herradura.In both cases the magnitude of the secondary flow that affects the bottom decreases and, therefore, weakens the horseshoe vortex.
2. Rugosidad no direccional 19 (Fig. 4, Fig. 5 y Fig. 6).- Es especialmente eficaz contra el segundo mecanismo de socavación (vórtices de von Karman), aunque también actúa contra el primer mecanismo (vórtice en herradura) si se crea en el borde o área de ataque de Ia estructura o del objeto sumergido. Recomiendo producir dicha rugosidad artificial no direccional en Ia superficie sumergida de Ia estructura que no pertenece al borde o área de ataque.2. Non-directional roughness 19 (Fig. 4, Fig. 5 and Fig. 6) .- It is especially effective against the second undermining mechanism (von Karman vortices), although it also acts against the first mechanism (horseshoe vortex) if It is created on the edge or area of attack of the structure or submerged object. I recommend producing said non-directional artificial roughness on the submerged surface of the structure that does not belong to the edge or area of attack.
La Fig. 5 muestra el tipo de rugosidad no direccional; consiste en un conjunto de elementos rugosos puntuales 19 en bajorrelieve o en altorrelieve de forma, tamaño y distribución tales que provocan que Ia capa límite laminar (formada por partículas que fluyen ordenadamente), que se desplaza en contacto con Ia superficie de Ia estructura o del objeto sumergido, se transforme en turbulenta (formada por partículas que fluyen caóticamente). Esta transformación da por resultado que Ia separación de dicha capa límite (Fig. 3) ocurra en puntos 16 localizados más aguas abajo que en el caso de una superficie lisa (Fig. 2), reduciendo así las dimensiones y Ia intensidad de la estela turbulenta 17 de la estructura sumergida 10, Io que produce una menor socavación, como se explicó en el apartado referente al estado de Ia técnica.Fig. 5 shows the type of non-directional roughness; It consists of a set of rough rough elements 19 in bas-relief or in relief of shape, size and distribution such that they cause the laminar boundary layer (formed by particles that flow in an orderly manner), which moves in contact with the surface of the structure or of the structure. submerged object, it becomes turbulent (formed by particles that flow chaotically). This transformation results in the separation of said boundary layer (Fig. 3) occurring at points 16 located further downstream than in the case of a smooth surface (Fig. 2), thus reducing the dimensions and The intensity of the turbulent wake 17 of the submerged structure 10, which produces less undercutting, as explained in the section referring to the state of the art.
En comparación con las distintas medidas y soluciones proporcionadas por el estado de Ia técnica, mencionadas en este documento, mi invención, además de permitir una mayor eficiencia en Ia reducción de Ia socavación, presenta las siguientes ventajas:In comparison with the different measures and solutions provided by the state of the art, mentioned in this document, my invention, in addition to allowing greater efficiency in the reduction of undercutting, has the following advantages:
(a) Permite una reducción significativa en los costos de construcción, ya que Ia creación de Ia rugosidad artificial no requiere volúmenes adicionales de obra, ni tiempos adicionales de construcción, ni maquinaria, ni técnicas especializadas.(a) It allows a significant reduction in construction costs, since the creation of artificial roughness does not require additional volumes of work, nor additional construction times, machinery, or specialized techniques.
(b) Elimina los gastos de mantenimiento o de reparación de los medios o elementos usados contra Ia socavación, ya que Ia rugosidad producida no sufre desgaste ni deformación ni una consecuente pérdida de eficiencia, a diferencia de Ia mayoría de las soluciones convencionales, como las que funcionan a base de colchones o carpetas de geotextiles.(b) Eliminates the maintenance or repair costs of the means or elements used against the undercutting, since the roughness produced does not suffer wear or deformation or a consequent loss of efficiency, unlike most conventional solutions, such as that work based on mattresses or geotextile folders.
(c) Resiste cualesquiera condiciones hidrodinámicas de velocidad y de turbulencia, a diferencia de muchas de las soluciones que utilizan elementos colocados en el fondo y otras.(c) Resists any hydrodynamic conditions of speed and turbulence, unlike many of the solutions that use elements placed at the bottom and others.
(d) Minimiza o elimina Ia necesidad de proteger el fondo y de construir apéndices o elementos agregados.(d) Minimizes or eliminates the need to protect the fund and build appendices or aggregate elements.
(e) No produce efectos parásitos de socavación aguas abajo de Ia estructura sumergida y que pueden llegar a afectar a dicha estructura, a diferencia de algunas de las soluciones pertenecientes al estado de Ia técnica.(e) It does not produce parasitic effects of undercutting downstream of the submerged structure and which may affect said structure, unlike some of the solutions belonging to the state of the art.
(f) No interfiere con Ia estética de Ia estructura a proteger, puesto que Ia rugosidad producida se mantiene bajo el nivel de Ia superficie libre del agua.(f) It does not interfere with the aesthetics of the structure to be protected, since the roughness produced is maintained below the level of the free water surface.
(g) La tecnología es sencilla, de fácil transferencia y aplicación. Un análisis detallado de Ia descripción de mi invención y de las figuras correspondientes permite apreciar otras modalidades de utilización y otras ventajas de mi invención con respecto al estado de Ia técnica.(g) The technology is simple, easy to transfer and apply. A detailed analysis of the description of my invention and the corresponding figures allows us to appreciate other modalities of use and other advantages of my invention with respect to the state of the art.
El uso de rugosidad artificial para reducir Ia intensidad de Ia estela turbulenta como medio para disminuir Ia socavación local en estructuras y objetos sumergidos constituye una importante novedad técnica de Ia presente invención y es una aplicación original de dicho efecto de reducción de Ia estela turbulenta, ya conocido por Ia Mecánica de Fluidos y aplicado en otro campo de Ia técnica. Se emplea rugosidad artificial en las pelotas usadas en algunos deportes (béisbol, tenis, golf) para reducir las estelas turbulentas que dichas pelotas forman en el aire, aunque en estos casos el objetivo es disminuir Ia fuerza de arrastre, que es Ia fuerza que se opone al movimiento, y lograr mayores velocidades y mayores distancias de recorrido de dichas pelotas.The use of artificial roughness to reduce the intensity of the turbulent wake as a means to decrease the local undercutting in submerged structures and objects constitutes an important technical novelty of the present invention and is an original application of said turbulent wake reduction effect, since known for the Mechanics of Fluids and applied in another field of the technique. Artificial roughness is used in the balls used in some sports (baseball, tennis, golf) to reduce the turbulent trails that these balls form in the air, although in these cases the objective is to decrease the drag force, which is the force that is opposes the movement, and achieve greater speeds and greater distances of travel of these balls.
Los resultados favorables de Ia aplicación de Ia rugosidad artificial creada por esta invención han sido comprobados con 2 estudios experimentales en laboratorio de Hidráulica, utilizando modelos físicos reducidos con las características indicadas en Ia siguiente descripción abreviada; en dicha descripción se utiliza los siguientes parámetros hidrodinámicos adimensionales, de uso común en Ia Hidráulica:The favorable results of the application of the artificial roughness created by this invention have been verified with 2 experimental studies in a hydraulics laboratory, using reduced physical models with the characteristics indicated in the following abbreviated description; in said description the following dimensionless hydrodynamic parameters are used, commonly used in Hydraulics:
Número de Fraude: F =
Figure imgf000015_0001
Fraud Number: F =
Figure imgf000015_0001
donde U es Ia velocidad media del flujo, g es Ia aceleración debida a Ia gravedad y d es Ia profundidad del flujo.where U is the average velocity of the flow, g is the acceleration due to gravity and d is the depth of the flow.
T, UD Número de Reynolds: R = v T , UD Reynolds number: R = v
donde U es Ia velocidad media del flujo, D es el diámetro de Ia pila cilindrica y v es el coeficiente de viscosidad cinemática del líquido. En el primer estudio, se utilizó un canal de sección rectangular de 0,56 metros de ancho, un caudal de 21 ,6 litros/segundo y como material de fondo, baquelita molida con una velocidad de inicio de movimiento de 0,14 metros/segundo. Se ensayó con pilas cilindricas con un diámetro de 0,07 metros y Ia profundidad de flujo fue de 0,27 metros. El Número de Fraude fue de 0,09 y el de Reynolds, de 8,8 X 103.where U is the average flow velocity, D is the diameter of the cylindrical cell and v is the coefficient of kinematic viscosity of the liquid. In the first study, a rectangular section channel of 0.56 meters wide was used, a flow of 21.6 liters / second and as background material, ground bakelite with a movement start speed of 0.14 meters / second. It was tested with cylindrical batteries with a diameter of 0.07 meters and the flow depth was 0.27 meters. The Fraud Number was 0.09 and that of Reynolds was 8.8 X 10 3 .
El segundo estudio se realizó en un canal de sección rectangular de 1 ,50 metros de ancho, con un caudal que varió entre 49,5 y 59,4 litros/segundo; el material del fondo fue arena y su velocidad de inicio de movimiento fue de 0,22 metros/segundo. Se creó rugosidad artificial en pilas cilindricas de 0,10 metros de diámetro; Ia profundidad de flujo varió de 0,12 metros a 0,20 metros. Los valores del Número de Fraude variaron entre 0,14 y 0,27 y los valores del Número de Reynolds, entre 1 ,7 X 104 y 2,7 X 104.The second study was conducted in a rectangular section channel of 1.50 meters wide, with a flow rate that varied between 49.5 and 59.4 liters / second; The bottom material was sand and its movement start speed was 0.22 meters / second. Artificial roughness was created in cylindrical batteries of 0.10 meters in diameter; The depth of flow varied from 0.12 meters to 0.20 meters. The Fraud Number values varied between 0.14 and 0.27 and the Reynolds Number values, between 1, 7 X 10 4 and 2.7 X 10 4 .
Los resultados de ambos estudios de laboratorio mostraron una reducción significativa de Ia profundidad y del volumen del foso de socavación en pilas con diferentes alternativas de Ia rugosidad artificial, con respecto a los valores correspondientes a Ia pila lisa en las mismas condiciones hidrodinámicas.The results of both laboratory studies showed a significant reduction in the depth and volume of the undercutting pit in piles with different alternatives of artificial roughness, with respect to the values corresponding to the smooth stack in the same hydrodynamic conditions.
Por Io anteriormente descrito, puede apreciarse que mi invención representa un avance considerable en Ia solución de Ia problemática relativa a Ia socavación local alrededor de las estructuras sumergidas. La solución aquí presentada incrementa Ia seguridad de dichas estructuras, aumenta Ia vida útil y reduce los costos y los tiempos de construcción, los de mantenimiento y, eventualmente, los de reparación o de reconstrucción.From the above described, it can be seen that my invention represents a considerable advance in the solution of the problem related to local undercutting around submerged structures. The solution presented here increases the security of these structures, increases the useful life and reduces the costs and times of construction, maintenance and, eventually, those of repair or reconstruction.
BREVE DESCRIPCIÓN DE LAS FIGURASBRIEF DESCRIPTION OF THE FIGURES
Fig. 1 Mecanismos de socavación local (vista en perspectiva)Fig. 1 Local undermining mechanisms (perspective view)
(ESTADO DE LA TÉCNICA) Fig. 2 Estela turbulenta de gran magnitud y de gran intensidad(STATE OF THE TECHNIQUE) Fig. 2 Turbulent wake of great magnitude and great intensity
(vista en planta) (ESTADO DE LA TÉCNICA)(plan view) (STATE OF THE TECHNIQUE)
Fig. 3 Estela turbulenta de pequeña magnitud y de pequeña intensidad (vista en planta) (ESTADO DE LA TÉCNICA)Fig. 3 Turbulent wake of small magnitude and small intensity (plan view) (STATE OF THE TECHNIQUE)
Fig. 4 Molde con rugosidad direccional y con rugosidad no direccionalFig. 4 Mold with directional roughness and non-directional roughness
(vista en perspectiva)(perspective view)
Fig. 5 Rugosidad no direccional (vista de frente)Fig. 5 Non-directional roughness (front view)
Fig. 6 Estructura sumergida con rugosidad artificial direccional y con rugosidad artificial no direccional (perspectiva).Fig. 6 Submerged structure with directional artificial roughness and non-directional artificial roughness (perspective).
MEJOR MÉTODO CONOCIDO PARA EJECUTAR LA INVENCIÓNBEST METHOD KNOWN TO EXECUTE THE INVENTION
Se presenta las siguientes recomendaciones para llevar a cabo Ia ejecución de Ia invención, como ejemplo y no con Ia intención de limitar indebidamente el alcance de Ia misma.The following recommendations are presented to carry out the execution of the invention, as an example and not with the intention of unduly limiting the scope thereof.
La Fig. 4 muestra las características principales.Fig. 4 shows the main features.
Recomiendo que el molde para crear Ia rugosidad artificial sea fabricado de un material tal como caucho o un polímero, plástico o un material similar que sea flexible y que no sea excesivamente elástico (para conservar las formas, las proporciones y las distribuciones de los salientes y de los bajorrelieves que servirán para crear Ia rugosidad artificial). La forma del molde puede ser Ia de una capa o placa cuyas dimensiones obedezcan a las siguientes indicaciones:I recommend that the mold to create the artificial roughness be made of a material such as rubber or a polymer, plastic or a similar material that is flexible and that is not excessively elastic (to preserve the shapes, proportions and distributions of the protrusions and of the bas-reliefs that will serve to create the artificial roughness). The shape of the mold can be that of a layer or plate whose dimensions obey the following indications:
(a) espesor: el necesario para alojar a los salientes o a las oquedades que producirán Ia rugosidad artificial y además mantener un margen para conservar cierta resistencia al manejo; (b) longitud: Ia necesaria para rodear a Ia estructura que se desea proteger de Ia socavación;(a) thickness: that necessary to accommodate the projections or the recesses that will produce the artificial roughness and also maintain a margin to maintain a certain resistance to handling; (b) length: the one necessary to surround the structure to be protected from undercutting;
(c) anchura: Ia suficiente para que Ia rugosidad artificial actúe.(c) width: enough for the artificial roughness to act.
El molde puede ser utilizado en cuando menos dos formas:The mold can be used in at least two ways:
(a) puede ser colocado dentro de los moldes para el vaciado del concreto (o del material similar utilizado para construir Ia estructura, en su caso), en Ia posición apropiada para crear en las zonas adecuadas de Ia estructura resultante los dos tipos de rugosidad artificial;(a) it can be placed inside the molds for the emptying of concrete (or similar material used to build the structure, if applicable), in the appropriate position to create in the appropriate areas of the resulting structure the two types of roughness artificial;
(b) puede ser sujetado rodeando exteriormente a Ia estructura ya construida, con una cierta separación para producir Ia rugosidad artificial en un material vaciado que sería utilizado para construir una cubierta alrededor de dicha estructura. En este caso, se puede colocar el molde según un perfil hidrodinámico, obteniéndose así una mejora en las condiciones del flujo y, por tanto, una reducción adicional de Ia socavación.(b) it can be fastened by externally surrounding the already constructed structure, with a certain separation to produce the artificial roughness in an emptied material that would be used to build a roof around said structure. In this case, the mold can be placed according to a hydrodynamic profile, thus obtaining an improvement in the flow conditions and, therefore, an additional reduction of the undercut.
Recomiendo las siguientes características para los dos tipos de rugosidad artificial producidos por mi invención.I recommend the following characteristics for the two types of artificial roughness produced by my invention.
1. Rugosidad direccional.1. Directional roughness.
En Ia Fig. 4 y en Ia Fig. 6 se muestra uno de los trazos posibles de los elementos rugosos lineales siguiendo los lineamientos establecidos en Ia descripción detallada de Ia invención; las estrías 18 mostradas en las figuras son una familia de curvas elípticas cuyo eje menor es vertical y cuyo eje mayor es horizontal. Puede trazarse dichas líneas con otras formas: arcos de círculos, parábolas, curvas no regulares, segmentos de rectas, etc. Las franjas pueden ser sustituidas por elementos rugosos puntuales alineados según las líneas mencionadas; Ia descripción de los elementos rugosos puntuales aparece más adelante, en el inciso 2, referente a Ia rugosidad no direccional. Las características geométricas básicas que recomiendo para este tipo de rugosidad son las siguientes:In Fig. 4 and in Fig. 6 one of the possible lines of the linear rough elements is shown following the guidelines established in the detailed description of the invention; the stretch marks 18 shown in the figures are a family of elliptical curves whose minor axis is vertical and whose major axis is horizontal. You can draw these lines in other ways: arcs of circles, parabolas, non-regular curves, line segments, etc. The stripes can be replaced by specific rough elements aligned according to the mentioned lines; The description of the point rough elements appears later, in part 2, referring to the non-directional roughness. The basic geometric characteristics that I recommend for this type of roughness are the following:
a. Estrías (en bajorrelieve):to. Stretch marks (bas-relief):
Estrías con una profundidad de 0,5 centímetros a 5 centímetros y una sección transversal semicircular o rectangular, con un ancho igual al doble de Ia profundidad. Recomiendo un espacio libre entre estrías aproximadamente igual a Ia profundidad. Dichas estrías, sin embargo, pueden tener otras formas de sección transversal y otras dimensiones y proporciones.Stretch marks with a depth of 0.5 centimeters to 5 centimeters and a semicircular or rectangular cross section, with a width equal to twice the depth. I recommend a free space between stretch marks approximately equal to the depth. Such stretch marks, however, may have other cross-sectional shapes and other dimensions and proportions.
Las estrías pueden ser sustituidas por depresiones o espacios entre elementos rugosos puntuales alineados según las curvas mencionadas; Ia descripción de los elementos rugosos puntuales aparece más adelante, en el inciso 2, referente a Ia rugosidad no direccional.Stretch marks can be replaced by depressions or spaces between rough rough elements aligned according to the mentioned curves; The description of the point rough elements appears later, in part 2, referring to the non-directional roughness.
b. Bordes (en altorrelieve):b. Borders (in high relief):
Altura de los bordes salientes: de 0,5 centímetros a 5 centímetros; recomiendo que su sección transversal sea preferentemente rectangular con las aristas redondeadas, con un ancho igual al doble de Ia altura. Se recomienda un espacio libre entre bordes salientes aproximadamente igual a Ia profundidad. Los bordes mencionados pueden tener otras formas de sección transversal y otras dimensiones y proporciones. Los bordes pueden ser sustituidos por elementos rugosos puntuales alineados según las curvas mencionadas; Ia descripción recomendada de los elementos rugosos puntuales aparece más adelante, en el inciso 2, referente a Ia rugosidad no direccional.Height of the projecting edges: from 0.5 centimeters to 5 centimeters; I recommend that its cross section is preferably rectangular with rounded edges, with a width equal to twice the height. A free space between protruding edges approximately equal to the depth is recommended. The mentioned edges may have other cross-sectional shapes and other dimensions and proportions. The edges can be replaced by specific rough elements aligned according to the mentioned curves; The recommended description of the specific rough elements appears later, in part 2, referring to the non-directional roughness.
La zona o área de ataque de Ia estructura o del objeto sumergido es fácilmente identificable cuando Ia sección transversal horizontal de Ia estructura o del objeto sumergido es rectangular o cuadrada, ya que es el área sumergida que da frente a Ia corriente. En el caso de que Ia forma de Ia sección transversal horizontal de dicha estructura u objeto sumergido sea circular, el área de ataque puede ser definida como el área comprendida verticalmente entre Ia superficie libre del agua y el fondo y, horizontalmente, entre dos líneas verticales trazadas sobre Ia superficie de Ia pila que da frente al flujo, definidas por dos radios horizontales que forman un ángulo de aproximadamente 10 grados sexagesimales a un lado y otro del radio paralelo a Ia dirección de Ia corriente.The area or area of attack of the structure or the submerged object is easily identifiable when the horizontal cross-section of the structure or the submerged object is rectangular or square, since it is the submerged area that faces the current. In the event that the shape of the horizontal cross section of said submerged structure or object is circular, the area of attack can be defined as the area vertically between the free surface of the water and the bottom and, horizontally, between two vertical lines drawn on the surface of the stack facing the flow, defined by two horizontal radii that form an angle of approximately 10 sexagesimal degrees to one side and another of the radius parallel to the direction of the Ia stream.
2. Rugosidad no direccional.2. Non-directional roughness.
Las características básicas que recomiendo para este tipo de rugosidad artificial son las siguientes:The basic characteristics that I recommend for this type of artificial roughness are the following:
a). Forma y tamaño de los elementos rugosos puntuales: de preferencia, en forma de ranuras (en bajorrelieve) o de salientes (en altorrelieve) de trazo circular y sección transversal semicircular. La Fig. 5 muestra esta geometría. Recomiendo que el diámetro exterior sea de 1 centímetro a 5 centímetros y el diámetro interior, de 0,6 centímetros a 3 centímetros, conservando entre el diámetro exterior y el interior una relación de aproximadamente 5/3. Dichos elementos también pueden tener otras formas, como: casquete esférico, cilindro, cubo, etc. y también tener otros tamaños. Las proporciones entre las dimensiones mencionadas también pueden ser diferentes.to). Shape and size of the point rough elements: preferably, in the form of grooves (in bas-relief) or projections (in relief) of circular lines and semicircular cross-section. Fig. 5 shows this geometry. I recommend that the outer diameter be 1 centimeter to 5 centimeters and the inner diameter, 0.6 centimeters to 3 centimeters, keeping between the outer and inner diameter a ratio of approximately 5/3. These elements may also have other shapes, such as: spherical cap, cylinder, hub, etc. And also have other sizes. The proportions between the mentioned dimensions may also be different.
b). Distribución de los elementos (Fig. 5): preferentemente, a tresbolillo; esto es, en filas paralelas y tal que los elementos de una fila correspondan con los espacios de Ia fila siguiente y se forme así una red de triángulos equiláteros. Recomiendo que el espacio libre entre elementos sea aproximadamente igual a Ia diferencia entre los diámetros exterior e interior del inciso anterior. También puede usarse otras distribuciones: rectangular, romboidal, irregular, etc.b). Distribution of the elements (Fig. 5): preferably, with three sticks; that is, in parallel rows and such that the elements of a row correspond to the spaces of the next row and thus form a network of equilateral triangles. I recommend that the free space between elements be approximately equal to the difference between the outer and inner diameters of the previous paragraph. Other distributions can also be used: rectangular, rhomboidal, irregular, etc.
Hay estructuras y objetos situados en cárcavas o barrancas y en cuerpos de agua en los cuales Ia corriente mantiene aproximadamente una sola dirección, como ocurre con las pilas y estribos de puentes en ríos sin influencia de Ia marea. En ese caso, recomiendo que mi invención cree los dos tipos de rugosidad en cada estructura u objeto: Ia rugosidad direccional o una combinación de los dos tipos de rugosidad en el área de ataque y Ia rugosidad no direccional en el resto del área sumergida de Ia estructura o del objeto. En el caso de las estructuras y de los objetos situados en cuerpos de agua en los que Ia corriente puede presentarse en diferentes direcciones, como en un medio lagunar, estuarino, costero o marino, recomiendo que mi invención produzca uno de los dos tipos de rugosidad, o una combinación de ambos, en toda Ia superficie sumergida de Ia estructura o del objeto.There are structures and objects located in gullies or ravines and in bodies of water in which the current maintains approximately one direction, as is the case with bridge piles and stirrups in rivers without tidal influence. In that case, I recommend that my invention create the two types of roughness in each structure or object: the directional roughness or a combination of the two types of roughness in the area of attack and the non-directional roughness in the rest of the submerged area of the Ia structure or object. In the case of structures and objects located in bodies of water in which the current can occur in different directions, such as in a lagoon, estuarine, coastal or marine environment, I recommend that my invention produce one of two types of roughness , or a combination of both, in the entire submerged surface of the structure or object.
La Fig. 6 muestra una estructura sumergida de forma cilindrica en Ia cual mi molde ha creado rugosidad direccional 18 y rugosidad no direccional 19.Fig. 6 shows a submerged cylindrical structure in which my mold has created directional roughness 18 and non-directional roughness 19.
Aunque en este documento se presenta recomendaciones específicas respecto a las características de mi invención, dichas recomendaciones tienen el objeto de ejemplificar el uso de dicha invención y por tanto no son limitativas; es posible hacerles a dichas características diferentes combinaciones, modificaciones y adiciones, Io cual no altera el espíritu ni el alcance de mi invención, tal como aparecen en las reivindicaciones.Although specific recommendations regarding the characteristics of my invention are presented in this document, said recommendations are intended to exemplify the use of said invention and are therefore not limiting; it is possible to make said characteristics different combinations, modifications and additions, which does not alter the spirit or the scope of my invention, as they appear in the claims.
POSIBILIDADES DE APLICACIÓN INDUSTRIALINDUSTRIAL APPLICATION POSSIBILITIES
Mi invención puede utilizarse para aumentar Ia seguridad contra Ia socavación local e incrementar Ia vida útil, así como para reducir los costos de construcción, de mantenimiento o de reparación de estructuras y objetos sumergidos en una corriente o flujo. Esas estructuras pueden ser pilas y estribos de puentes, pilotes, columnas, soportes de equipo y de maquinaria, conductos y estructuras y objetos similares. Dichos objetos pueden estar apoyados, anclados, hincados o enterrados en el fondo o en las márgenes de cárcavas o barrancas o en medios fluviales, lagunares, estuarinos, costeros y marinos susceptibles de sufrir socavación por corrientes naturales tanto permanentes como efímeras, o en conductos artificiales.My invention can be used to increase security against local undermining and increase the useful life, as well as to reduce the costs of construction, maintenance or repair of structures and objects submerged in a current or flow. These structures can be piles and stirrups of bridges, piles, columns, equipment and machinery supports, ducts and similar structures and objects. Such objects may be supported, anchored, driven or buried at the bottom or on the banks of gullies or ravines or in river, lagoon, estuarine, coastal and marine environments susceptible to being undermined by both permanent and ephemeral natural currents, or in artificial conduits. .
También puede utilizarse Ia presente invención para reducir Ia estela turbulenta formada por estructuras y objetos sumergidos en un flujo y que forman parte de una obra hidráulica, como es el caso de las columnas y muros de apoyo de compuertas, de estructuras de cruce y de control, de los muros y columnas en cárcamos de bombeo, etc. The present invention can also be used to reduce the turbulent wake formed by structures and objects submerged in a flow and that are part of a hydraulic work, such as the columns and walls supporting gates, crossing structures and control , of the walls and columns in pumping tanks, etc.

Claims

REIVINDICACIONESHabiendo descrito suficientemente mi invención, considero como una novedad y por Io tanto reclamo como de mi exclusiva propiedad Io contenido en las siguientes cláusulas: CLAIMS Having sufficiently described my invention, I consider it as a novelty and therefore claim as my exclusive property contained in the following clauses:
1. Un molde para vaciado de estructuras y objetos que permanecen sumergidos en una comente, caracterizado por que produce en dichos objetos una rugosidad artificial especialmente diseñada para reducir los flujos secundarios y las estelas turbulentas debidos a Ia presencia de dichos objetos en dicha corriente.1. A mold for emptying structures and objects that remain submerged in a comment, characterized in that it produces in said objects an artificial roughness specially designed to reduce secondary flows and turbulent trails due to the presence of said objects in said current.
2. El molde de Ia Reivindicación 1 , caracterizado por que dicha rugosidad artificial incluye elementos rugosos en bajorrelieve.2. The mold of claim 1, characterized in that said artificial roughness includes rough elements in bas-relief.
3. El molde de Ia Reivindicación 1 , caracterizado por que dicha rugosidad artificial incluye elementos rugosos en altorrelieve.3. The mold of claim 1, characterized in that said artificial roughness includes rough relief elements.
4. Un método para reducir los flujos secundarios y las estelas turbulentas debidos a Ia presencia de estructuras y objetos sumergidos en un flujo, que consiste en producir rugosidad artificial de diseño especial sobre Ia superficie de dichas estructuras y objetos sumergidos durante el vaciado, por medio de un molde.4. A method to reduce secondary flows and turbulent steles due to the presence of structures and objects submerged in a flow, which consists in producing artificial roughness of special design on the surface of said structures and objects submerged during emptying, by means of of a mold.
5. El método de Ia Reivindicación 4, caracterizado por que dicha rugosidad artificial incluye elementos rugosos en bajorrelieve.5. The method of claim 4, characterized in that said artificial roughness includes rough elements in bas-relief.
6. El método de Ia Reivindicación 4, caracterizado por que dicha rugosidad artificial incluye elementos rugosos en altorrelieve. 6. The method of claim 4, characterized in that said artificial roughness includes rough relief elements.
PCT/MX2005/000053 2005-07-12 2005-07-12 Mould for creating artificial roughness that protects against scouring WO2007008054A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/MX2005/000053 WO2007008054A1 (en) 2005-07-12 2005-07-12 Mould for creating artificial roughness that protects against scouring

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/MX2005/000053 WO2007008054A1 (en) 2005-07-12 2005-07-12 Mould for creating artificial roughness that protects against scouring

Publications (1)

Publication Number Publication Date
WO2007008054A1 true WO2007008054A1 (en) 2007-01-18

Family

ID=37637368

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/MX2005/000053 WO2007008054A1 (en) 2005-07-12 2005-07-12 Mould for creating artificial roughness that protects against scouring

Country Status (1)

Country Link
WO (1) WO2007008054A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2162347A1 (en) * 2007-05-25 2010-03-17 The Regents of the University of Michigan Enhancement of vortex induced forces and motion through surface roughness control

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES463014A1 (en) * 1976-10-05 1978-07-16 Doris Dev Richesse Sous Marine Vibration suppressor for water immersed column - has staggered random ribs in helical path to break up regular vortices
US6092766A (en) * 1995-12-12 2000-07-25 Ulrich Laroche Process for forming a surface for contact with a flowing fluid and body with such surface regions
WO2002095278A1 (en) * 2001-05-18 2002-11-28 Crp Group Limited Protection of underwater elongate members
US20040013473A1 (en) * 2000-08-30 2004-01-22 Robert Gibson Protection of underwater elongate members
US20050003146A1 (en) * 2001-06-21 2005-01-06 Bernd Spath Body with improved surface properties
US20050023433A1 (en) * 2003-07-31 2005-02-03 Alps Electric Co., Ltd. Resin optical component mold having minute concavo-convex portions and method of manufacturing resin optical component using the same

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES463014A1 (en) * 1976-10-05 1978-07-16 Doris Dev Richesse Sous Marine Vibration suppressor for water immersed column - has staggered random ribs in helical path to break up regular vortices
US6092766A (en) * 1995-12-12 2000-07-25 Ulrich Laroche Process for forming a surface for contact with a flowing fluid and body with such surface regions
US20040013473A1 (en) * 2000-08-30 2004-01-22 Robert Gibson Protection of underwater elongate members
WO2002095278A1 (en) * 2001-05-18 2002-11-28 Crp Group Limited Protection of underwater elongate members
US20050003146A1 (en) * 2001-06-21 2005-01-06 Bernd Spath Body with improved surface properties
US20050023433A1 (en) * 2003-07-31 2005-02-03 Alps Electric Co., Ltd. Resin optical component mold having minute concavo-convex portions and method of manufacturing resin optical component using the same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2162347A1 (en) * 2007-05-25 2010-03-17 The Regents of the University of Michigan Enhancement of vortex induced forces and motion through surface roughness control
EP2162347A4 (en) * 2007-05-25 2013-12-04 Univ Michigan Enhancement of vortex induced forces and motion through surface roughness control

Similar Documents

Publication Publication Date Title
WO2007008053A1 (en) Covering element for protecting structures against scouring and drag force
US20120134753A1 (en) Bridge pier and abutment scour preventing apparatus with vortex generators
CN108978578B (en) Mountain front highway water damage prevention and control method based on split-flow stream theory and diversion dam
CN103334404A (en) Detachable flexible floating breakwater unit body
JPS61294009A (en) Protective apparatus wherein energy disipating element is mounted on bank
Tinkler et al. Recent adjustments to the long profile of Cooksville Creek, an urbanized bedrock channel in Mississauga, Ontario
WO2007008054A1 (en) Mould for creating artificial roughness that protects against scouring
CN101824809A (en) Large-gradient gravel river bank protective structure and river washout-resistant controlling method thereof
CN216238184U (en) Bridge temporary scouring protection device based on filling air bags
AU2012392206A1 (en) A versatile erosion control system
CN204185819U (en) Honeycomb dykes and dams shore protection component
CN211080094U (en) Erosion-resistant protection structure of lake beach
CN104612106B (en) A kind of permeable geotechnique soft raft structure
Eldho et al. Physical model study of scouring effects on pier foundations of bridges
Pinchard et al. Spillway capacity upgrade at Malarce dam: Design of an additional Piano Key Weir spillway
Ibrahim et al. Prediction of breach formation through the Aswan High Dam and subsequent flooding downstream
CN110939100A (en) Breakwater component and application thereof
CN215105047U (en) Prefabricated concrete hollow square wall type revetment
CN113430962B (en) Self-bursting type water passing bridge culvert suitable for area where mountain torrents are easy to occur
CN115613526A (en) Ditch valley type mud-rock flow flexible energy dissipation fender pile
MacBroom Bridge scour and sediment analysis for river restoration projects
Yang et al. Protection technology and applications of gabion
RU2222666C2 (en) Riverside protecting installation
CN112554129A (en) River channel dam with hydrophilic platform and steep rising and falling
KR101023690B1 (en) Revetment block having flow velocity reduction function

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 05761875

Country of ref document: EP

Kind code of ref document: A1