MXPA00008777A

MXPA00008777A - Structure for passage under an embankment

Info

Publication number: MXPA00008777A
Application number: MXPA/A/2000/008777A
Authority: MX
Inventors: Marcel Matiere
Original assignee: Societe Civile De Brevets Matiere
Priority date: 1998-03-09
Filing date: 2000-09-08
Publication date: 2001-07-09

Abstract

The invention concerns a structure for passage under an embankment (12), delimited by a tubular wall (1), comprising, in cross-section transverse to its axis (O), at least three elements, respectively a top element (3) supported by its lateral sides (31, 31') on the upper edges (21) of two side elements (2, 2') having a top part curved towards the axis (O). The invention is characterised in that each top element (3) comprises a wall (30) having a transverse profile with double curvature comprising a central part (33) with slight curvature extended by two end parts (34, 34') each having a common radius of curvature with the upper curved part (24, 24') of the corresponding side element (2, 2') and associated with at least a stiffening rib (32). The invention is particularly useful for building structures with large cross-section for road or railway traffic.

Description

PASSAGE STRUCTURE UNDER A FLOOR The invention relates to a passage structure below a shaft that can have a very wide section, which corresponds remarkably to the road clearance, said structure can be used particularly for passage below the embankment of a traffic through road or railway. The technical evolution, especially the need to build new lanes for transit, such as highway or high-speed rail, causes the multiplication of high passages. In fact, a railroad or a road must present a regular profile over long distances, without significant ramps and also requires the elimination of cruises. For some time the transit lanes have been built on an embankment that simplifies the profile, which requires the construction of numerous structures for the passage of secondary lanes of traffic, railways and rivers. In order to solve these problems, this inventor suggested, some years ago, to build structures under the embankment thanks to a new technology that has a great number of advantages and has taken advantage of an important development. This technology, described in particular in the European patents number 0.081.402 and number 0.244.890 of the same inventor consists of the construction of a tubular wall composed of prefabricated concrete elements, prepared in advance, transported on site if the prefabrication plant is distant, and assembled at the construction site, so that the entire structure is covered with an embankment. In general, the tubular wall is centered on a longitudinal axis and comprises, as a cross section, at least three prefabricated elements, respectively an upper element in the form of an arc of a circle, which rests on two lateral elements spaced between them and containing each one a base resting on the floor and a side wall with a curved upper part towards the inner part of the section in order to connect with the upper element. The previous invention allows to build fairly inexpensive structures with a very wide passage section corresponding to the width of a road clearing. It has even been possible to carry out, economically, structures that cover several lanes of road traffic, for example, in the case of bypass roads, in cities, which can be buried profitably to protect the environment. Obviously, it is more economical to employ as far as possible standard elements whose characteristics and performances are known and in practice, structures with a semicircular section comprising two lateral elements with a curved upper part in the form of an arc of a circle and are usually constructed. that connects with an upper element of the same radius of curvature. In the most common embodiment, the upper element comprises a circular sector of 90 °, in such a way that the faces joined between the lateral elements and the upper element are symmetrically inclined at 45 ° with respect to the vertical axis. The longitudinal joints usually consist of simple articulations with a horizontal axis and it has been observed that said configuration allows the construction of a very wide section structure and capable of sustaining important loads, for example, traffic in lanes of roads on the structure. However, the use of a semicircular section requires the construction of a relatively high structure in relation to its width since the latter is approximately equal to half the height. In order to increase the distance between the lateral elements, the inventor has therefore suggested the use of elements of different radii, where the upper element, which continues to cover an angular sector of 90 °, has a greater radius than the curved portions of the same. the lateral elements. Thus, the same configuration of the joints articulated between the elements is preserved, but the distance between these joints can be increased. However, the passage of the circular arc is to provide the distance and, since a larger radius is required, the elevation in the crown in relation to the supports of the sides may be too high to employ this technology when the difference in height between the bottom in which the structure is placed and the circulation lane passing above said bottom is insufficient. In such a case, the rectangular sectional passage structures may consist of a slab resting on two vertical walls, but the prefabrication technology may be used only for sections of reduced passage, in the order of 10 to 15 m2. For larger sizes, the prefabricated elements would not be comfortable and we would have to resort to classical bridge construction techniques. The purpose of the present invention is therefore to extend the possibilities of application of the civil engineering technology of prefabricated elements described in the patents mentioned above of this inventor, allowing the reduction of the total weight of the structure in relation to distance and preserving the essential advantages of the prior art. Accordingly, this invention relates, in general terms, to a passage structure beneath an embankment, comprising a tubular wall with a longitudinal axis and consisting of a number of concrete elements constructed in advance and juxtaposed along joints longitudinal and transverse, whereby said elements are assembled at the construction site to provide a tubular wall comprising, as cross section relative to its axis, at least three prefabricated elements, respectively, an upper element with two parallel lateral sides to the longitudinal axis and two lateral elements spaced between them, each containing a base resting on the ground and a side wall with a curved top towards the inner part of the section, with an upper edge parallel to the longitudinal axis, while the upper element is supported by its lateral sides along longitudinal joints, on the upper edges eriores of the lateral elements. In accordance with the present invention, each top element comprises a wall with a double curvature transverse profile comprising a central part of small curvature extending through two end portions each of which has the same radius of curvature as the upper curved part of the corresponding lateral element in order to connect tangentially with said element, while said double curvature wall is connected with at least one reinforcing rib capable of absorbing the stresses resulting from the own weight of the upper element and the load applied by the embankment covering the tubular wall. The curvature of the central part of the upper element is determined in such a way that the total height, in the crown, of the structure does not exceed a given limit and that the reinforcing rib has a sufficient moment of inertia to confer to the upper element the necessary resistance to bending, taking into account the distance between the side walls and the loads applied. In a particularly advantageous manner, the lateral sides of the upper element and the upper edges of the side elements are adjusted with corresponding support parts, recessed and protruding parts respectively, in order to offer two articulated longitudinal joints, while the tangential connection of Support parts of the upper element with the lateral elements determine the transmission of the supporting stresses in each longitudinal joint along inclined directions with respect to the horizontal axis, with a horizontal component facing outwards. Preferably, the longitudinal joint face between the upper edge of a lateral element and the lateral edge of the upper element that rests on the previous one passes through a common center of curvature and is inclined at approximately 45 ° with respect to the horizontal axis . But the invention will be better understood through the following description of a particular embodiment, provided by way of example and represented in the accompanying drawings. Figure 1 schematically shows, as a cross-section, a structure below an embankment in accordance with the invention. Figure 2 is a detailed view of a longitudinal joint. Figure 3 shows a variation. Figure 1 is a schematic representation, as a cross section, of a passage structure according to the invention, comprising a tubular wall 1 placed on the bottom 11, flattened and tamped, of a trench 10 and covered with an embankment 12 up to a top level 13 at a height h above the bottom 11 of the trench 10, to allow the passage of a circulation lane above the structure. The tubular wall 1 consists, generally, of prefabricated or prestressed reinforced concrete elements, juxtaposed to form successive sections centered on a horizontal axis 0. Said configuration has been described in detail, especially in the previous patents EP-0.08.402 and EP- 0.244. 890 of the same inventor. In general, each section comprises, as a cross section, at least three elements, respectively two lateral elements 2,2 'and an upper element 3 with two lateral sides 31, 31', parallel to the longitudinal axis or of the structure, resting on the upper edges 21, 21 'of the side element 2, 2'. Each side element 2, 2 'comprises a shoe 22 that forms a base with a flat bottom 22 and a side wall 23 that extends upward, curving inward at least in its upper section 24. The whole assembly is balanced in such a way that the prefabricated side element 2 can be placed on the floor and stand alone, without the need for scaffolding, even under the weight of the upper element 3. In the modalities described in the previous patent EP-0 081 402, the bases of the lateral element are connected by means of a foundation plate, which allows to distribute the applied load over a large surface. However, the foundation plate can be omitted without the load capacity of the bottom 11 of the trench allows the suppression of the foundation plate and, particularly, when the distance of the structure between the bases of the side elements 2, 2 '. It is significant. In a case of this type, each lateral element has the peculiar shape represented in figure 1, while the shoe 22 comprises two wings 22a, 22b which extend respectively towards the outside and towards the internal part in relation to the section, in each side of the base of the side wall 23 over a determined width in relation to the load capacity of the floor and based on the stability properties. Even though the wall 23 has an inward curve, experience has shown that said element can be perfectly stable, even in the case of very large distances. The structure described in the previous patent EP-0.081.402 has known a very important industrial development in addition to the numerous advantages provided by this original technology for the construction of civil engineering structures. Particularly, the cutting of the section of passages is carried out, in accordance with patent EP-0 081 402, in such a way that the longitudinal joints between the elements are placed in zones of voltage node whose positions can be determined while study the influence of the charges applied. Thus, elements of maximum size can be constructed and the number of elements that allow the construction of the required passage section can be reduced. Experience has shown that, in the case of a semicircular vault, these joints can be placed in such a way that both sides of the joint between the upper element and each lateral element present an inclination of 45 ° with respect to the horizontal axis.

Furthermore, it is particularly advantageous to provide articulated joints between each lateral side 31 of the upper element 3 and upper edge 21 of the related side element 2. These articulated joints are constructed as shown in Figure 2, whereby the upper edge 21 of the side element 2 is adjusted with a concave groove 41 while the side edge 31 of the upper element 3 is adjusted with a convex edge 42. The construction flexibility obtained in this way is quite high and considerably facilitates the execution of the embankment through successive layers that the joints allow slight displacements to adjust the elements. Furthermore, after laying, the stresses applied under the load of the embankment and of the overloads are transmitted tangentially by a vault effect, from the upper element to the lateral element that rests laterally on the embankment. In addition, beyond the high resistance provided by a proper placement of the joints between the elements, it is possible to reduce their weight, which facilitates their handling, even in the case of very large sizes. In the embodiments described in patent EP-0 081 402, the tubular wall of the structure has a semicircular section symbolized by the line of points Sl in figure 1. It can be seen that the height of the structure, in the crown, is equal to half the distance. The rectangular pathway in a structure of this type, for example, for a road traffic lane, therefore has a height that is approximately half the width. As indicated, in order to reduce the height of the structure in relation to its width, it is possible to provide the upper element with a radius of curvature greater than the radius of curvature of the lateral element to which it is connected tangentially, along the profile S2 illustrated as a dotted line in figure 1. In a case of this type, the gauge clearing G represented in the form of a mixed line in the figure shows a width L greater than twice the height H. However, the Overall height hl of the structure in the crown is still relatively important and can be too large when the difference in height h between the upper level of the transit lane 13 passing above the structure and the bottom 11 of said structure presents a reduced size . The invention offers a solution to this problem while retaining most of the advantages of the previously known configuration. As shown in Figure 1, the structure according to the present invention comprises, as a cross section with respect to its axis or, an upper element 3 that bears with its lateral sides 31, 31 'on the upper edges 21, 21 'of two side elements 2, 2' which can be perfectly identical to the side elements used in the previously known structure. Each side element 2 therefore comprises, as in the previous configuration, a side wall 23 whose upper part 24 is at least curved in order to provide a circular sector centered on a point 01 and extending vertically from a base in shoe shape containing two wings, respectively, an outer wing 22a and an inner wing 22b, which prevents the element 2 from tilting inward or outward. The upper element 3 shows, in reverse, a particular shape. It consists of a curved wall 30 connected to a reinforcing rib 32. The wall 30 has a cylindrical shape with generation of lines parallel to the longitudinal axis or and with a double curvature. It comprises a central part 33 with a very long radius of curvature connecting with two end portions 34, 34 'whose radius of curvature is equal to the radius of curvature of the curved upper part of the side wall 23, 23' of the related lateral element. 2, 2 '. Both parts 34 and 24 are therefore centered on the same point 01, 01 'and extend, respectively, on both sides of the joint face P. The central part 33 with large radius of curvature can be flat, as in the embodiment of Figure 1, and gradually connects with the end portions 34, 34 'centered in 01, O'l. The height e of the rib 32 is determined in order to give the assembly a moment of inertia sufficient to sustain the loads applied in part 33 of the element 3. Preferably, the elements are of such sizes that the longitudinal supports are spaced apart from each other. a distance L between them and placed at a height H above the bottom 11, while these sizes correspond to the track clearance required G. The joints 4, 4 'are then placed at the angles of this track clearance. The upper element 3 can be calculated as a beam of variable section resting on two articulated supports consisting of the longitudinal joints 4, 4 'provided on the upper edges 21, 21' of the lateral elements 2, 2 '. The height e is therefore not greater than the height of a flat floor plate that rests on two vertical supports, to limit said track clearance. Conversely, the particular shape of the end portions 34, 34 'of the upper element 3 allows maintaining the advantages of the previously known structure. For example, as shown in Figure 2, the articulated joint 4 can be constructed in the same manner, while the face seal P is preferably inclined with respect to the horizontal axis, by an angle A equal to 45 °.

We know that, in practice, this type of board has given excellent results, even in the case of very long distances. In addition, the tangential connection of the elements through the parts 24 and 34 of the same radius of curvature ensures the continuous transmission of the loads by a vault effect and maintains a certain flexibility of the structure, which is especially useful for holding settlements Differentials and, even in case of earthquakes as we can verify. Particularly, the loads applied to both articulated joints 4, 4 'have a horizontal component that tends to push the lateral elements 2, 2' outwards, elements that rest on the side embankments, so that the latter are constructed with the object to share the strength of the structure. Furthermore, the inwardly curved shape of the side elements 2, 2 'and the possibility of providing a very small thickness in relation to their length offers the overall assembly a certain flexibility that allows mobilizing the embankments. It appears that the overall height H 'of the structure is not significantly greater than the height of a rectangular section structure and therefore allows the passage of a circulation track 13 to a relatively low height H above the bottom 11 of the trench 10, so that the upper element 3 can be covered by a thin fill layer. It will be noted that the particular shape of the upper element allows the reduction of the settling effects which are normally observed at the limit of a flat floor plate and which causes the degradation of the floor of the road. In fact, since the central part 33 is extended by portions of greater curvature 34, the thickness of the embankment gradually increases up to the lateral supports 4, 4 'which are at a greater distance from the upper surface 13 and, owing to the continuity of the circular outer wall, said gradual increase or decrease in the height of the embankment above the concrete wall ensures a better absorption of the threshold effect in the passage of the structure. Obviously, the invention is not limited to the details of the modality just described and may present variations or improvements without departing from the protection framework defined by the claims. Particularly, in order to construct the upper element 33, conventional reinforced concrete technologies, especially prestressing, can be used in order to shorten the height of the reinforcement rib. The number of ribs associated with each element can also be increased. In addition, in the embodiment of figure 1, the lateral elements 2, 2 'have a center of curvature 01 placed on the bottom 11, in order to increase the height of the curved part 24 for a given relationship between the width L and the height H of the track. The side element however could have another shape as shown, for example, in Figure 3. In general, the height e of the rib should be sufficient to provide the upper element 3 with the necessary bending strength while ensuring the clearance of required way. In addition, in accordance with that described in patent EP-0 081 402, a concrete foundation plate that allows the load to be distributed over a large surface area can be connected to the internal edges of the bases 22, 22 'of the side elements. The reference signs inserted after the technical features mentioned in the claims are only for the purpose of facilitating the understanding of said claims and do not limit their extension in any way.

Claims

CLAIMS A passage structure below an embankment (12) comprising a tubular wall (1) with a longitudinal axis (o) and consisting of numerous concrete elements prepared in advance and juxtaposed along longitudinal and transverse joints, where said elements are assembled at the site of the construction in order to offer a tubular wall (1) comprising, as cross section in relation to its axis, at least three prefabricated elements, respectively an upper element (3) with two lateral sides (31, 31 ') parallel to the longitudinal axis (o) and two lateral elements (2, 2') spaced between them and each containing a base (22) that rests on the floor (11) and a side wall (23) ) with an upper part (29) curved towards the internal part of the section, with an upper edge (21) parallel to the longitudinal axis (o) while the upper element (3) is supported by its lateral sides (31, 31 ') ), along the longitudinal joints (4, 4 ') on the upper edges (21, 21') of the side elements (2, 2 '), characterized in that each upper element (3) comprises a wall (30) with a transverse profile with double curvature comprising a central part of small curvature (33) extended by two end parts (34, 34 ') each with the same radius of curvature as the upper curved part (24, 24') of the corresponding lateral element (2, 2 ') , with the object of tangential connection with said element, while said wall with double curvature (30) is connected with at least one reinforcing rib (32) capable of absorbing the stresses resulting from the own weight of the upper element (3) and of the load applied by the embankment (12) covering the tubular wall (1). A structure below an embankment according to claim 1, characterized in that the curve of the central part (33) of the upper element (3) is determined in such a way that the total height of the structure, in the crown, does not exceed a given limit and that the reinforcement rib (32) has a sufficient moment of inertia to provide the upper element (3) with the necessary bending strength, taking into account the distance between the lateral sides (31, 31 ') to hold loads applied. A structure below an embankment according to one of the previous claims, characterized in that the lateral sides (31, 31 ') of the upper element (3) and the upper edges (21, 21') of the lateral elements (2,
2) ') are fitted with corresponding support parts, respectively recess parts and projecting parts, to provide two articulated longitudinal joints (4, 4'), while the tangential connection of the support parts of the upper element (
3) with the elements laterals (2, 2 ') determine the transmission of the support stresses, in each longitudinal joint, along directions inclined with respect to the horizontal axis, with a horizontal component directed outwards. A structure below an embankment according to one of the previous claims, characterized in that the longitudinal joint face between the upper edge of the lateral element and the lateral edge of the upper element that rests on the previous one passes through a center of curvature common and is inclined approximately 45 ° in relation to the longitudinal axis. A structure below an embankment in accordance with one of the previous claims, capable of providing a clear rectangular path (G) of height (H) and width (L), characterized in that the sizes of the elements are determined in such a way that, after installation, the longitudinal joints (4, 4 ') between the elements are located approximately at the upper corners of the track clearance (G), so that the reinforcing ribs (32) of the upper elements (3) they have a lower face placed at a level corresponding approximately to the height (H) of the track clearance (G) and the longitudinal joints (4, 4 ') are spaced by a distance corresponding approximately to the width (L) of the clearance of via (G).