MXPA98010606A - Rigidizers covered with mixed concrete and metal material for metal plate arch type structures - Google Patents

Abstract

A reinforced corrugated metal arch structure of mixed concrete comprises: a first set of corrugated metal plates formed interconnected in a manner to define a base arch structure with the corrugations extending transversely of the length of the arch; Corrugated metal layers formed interconnected in a manner to cover the first set of interconnected plates of the base arch, the second series of plates has at least one corrugation extending transversely of the length of the arch with the channels of the corrugation of the second. series of plates secured to the ridges of the first group of plates, the interconnected series of the second plates and the first set of plates define an individual cavity, which extends transversely and with a continuous cover, said cavity is filled with concrete to define a concrete interface covered by the metal inner surfaces of the second series of ridges and the first set of channels: the internal surfaces of the cavity for each of the first and second plates have means for providing a cut flexure at the concrete-metal interface to provide individual curved beams running through the arch where the structure provides a positive and negative bending resistance and a combined axial load and bending resistance to the overload loads

Description

RIGIDIZERS COVERED WITH MIXED CONCRETE AND METAL MATERIAL FOR METAL PLATE ARCH TYPE STRUCTURES FIELD OF THE INVENTION The present invention relates to arch type structures of corrugated metal plate reinforced with concrete, such as those used in elevated bridges, water conduits or overpasses, capable of supporting large superimposed loads under low-lying decks such like heavy vehicular traffic and very particularly a structure that can be replaced by standard concrete structures or steel beam.

BACKGROUND OF THE INVENTION Over the years, corrugated metal sheets or plates have proven to be a durable, economical and versatile engineering material. Flexible arch-type structures made of corrugated metal plates have played an important role in the construction of culverts, river water collector, subdivisions, landfills, unevenness, conveyor conduits and service tunnels; for highways, roads, airports, municipalities, recreation areas, industrial parks, flood and conservation projects, depletion of water pollution and many other programs.

One of the main design challenges with respect to the arc-type structure of underground corrugated metal is that a relatively thin metal shell is required to withstand the relatively large load around its perimeter, such as the lateral pressures of the earth, underwater pressure, overload pressure as well as other live and / or dead loads in the structure. The capacity of this structure to resist perimeter loading, apart from being a function of the resistance of the surrounding soil, is directly related to the corrugation profile and the thickness of the shell. Since perimeter loads are distributed evenly, such as earth and water pressures, they generally do not create instability in an installed structure, the structure is more susceptible to uneven or localized load conditions such as the distribution of ground pressure. uneven during filling, or live loads in the installed structure due to vehicular traffic. The distribution of uneven ground pressure during the filling of the arch structure causes the structure to deform or peaks, giving the shape of the finished structure different from its structurally sound solid form. The live loads at the top of the structure, on the other hand, create a localized load condition that could cause a failure in the roof portion of the structure. A localized vertical load such as a live vehicular load imposed on an arc-type structure will create the bending stresses and axial stresses in the structure. The bending stresses are caused by the downward deformation of the roof, thereby generating positive bending moments in the crown portion of the structure and negative bending moments near the skirt portions of the structure. Axial stresses comprise stresses caused by a component of the live load acting along the fiber in cross section of the arc structure. In a design of an underground metal arc structure, the ratio of the bending stress to the axial stress experienced under a specific vertical load varies according to the thickness of the overload. The overload will be thicker as more vertical load is distributed when it reaches the arc structure and the structure is subject to less bending. The tension in an arc structure under a heavy overload is therefore mainly an axial tension. Corrugated metal sheets tend to fail more easily under bending than under axial compression. The conventional corrugated metal arch type design faces flexural stresses created by live loads by increasing the thickness of the overload, thus spending the live charges located in the thickness of the overload and on a larger surface in the arc, the bending stress in the arc is therefore brought to a minimum and most of the load is converted into axial forces . However, it is obvious that, by increasing the thickness of the overload, the pressure of the earth in the structure increases and therefore stronger metal plates are required. The need for a heavy overload also creates severe design limitations, such as the limitation on the size of the overhang under the structure or the approach angle of a highway to the structure. In a situation where the thickness of the overload is limited and has low height, the problem of live load is traditionally solved by locating an elongated tension discharge slab, usually made of reinforced concrete, near or immediately below the highway. which extends above the low fill area. The elongated slab will act as a load dispersion device so that the localized vehicle loads are distributed over a larger area on the metal arc surface. The problem with the stress relief slab is that it requires a fabrication site that involves additional manufacturing time and substantial labor and material costs. Also, in areas where concrete is not available, this is not a viable option. Attempts have been made to stretch a corrugated metal arch structure by the use of reinforcement ribs. In the patent of E.U.A. No. 4,141,666, reinforcement members are used on the outside of a box culvert to increase their cargo transportation capacity. The problem with said invention is that the sections of the structure between the reinforcement ribs are considerably weaker than in the reinforcement ribs and therefore, when loaded, there is a differential deflection or a rippling effect along the structure . To reduce this problem, the longitudinal members are secured to the interior of the culvert to reduce ripple, particularly along the crown and base portions. However, it is evident that when these structures are used in current beds or the like, it is not desirable to include any junction within the structure due to their tendency to be destroyed by ice flows and floods. In the patent of E.U.A. 4,318,635, multiple arc-shaped reinforcement ribs are applied to the interior / exterior of the culverts to provide reinforcement of the sides, crown and intermediate shoulder or skirt portions. Although said separate reinforcement ribs improve the strength of the structure to resist the loads, they do not solve the problem of undulation in the structure and can add unnecessary weight to the structure by superfluous reinforcement. In addition to the above drawbacks, the reinforcing ribs of this type of structure often require time and are complicated in their installation, adversely affecting construction costs. In addition, where widely spaced rib stiffeners are used, structural design analysis becomes difficult for such structures. The discontinuity of reinforcement and therefore, the variation in stiffness in the length of the structure makes it difficult to develop the total plastic moment capacity of the section, thus resulting in a design that is usually unnecessarily conservative and not very economic The Patent of E.U.A. 3,508,406 a Fisher describes a mixed arch structure having a flexible corrugated metal shell with concrete supports extending longitudinally on either side of the structure. Specifically, it is taught that in the case of a wide interval arc structure, the concrete bras can be connected with additional stiffener members that extend into the upper portion of the structure. Similarly, in the U.S. Patent. 4,390,306 to the same inventor, an arc structure is taught in which a stiffness and load distribution member is structurally fixed to the crown portion of the arc extending longitudinally for most of the length of the structure. It is also provided that the mixed arch structure should preferably include longitudinally extending bras that distribute the load on either side of the arch structure. The stiffener and brassieres extending longitudinally at the top may be made of concrete or metal and may even consist of sections of corrugated plate having their edges extending in the length direction of the culvert.

In Fisher's Patents, continuous reinforcement is provided along the structure by the crown stiffener and brassieres. The bras are designed to provide stability to the flexible structure during the installation stage, that is, before the structure is completely buried and supported by the filling. These provide consolidated material lengths in locations to resist distortion when compaction and filling equipment are used, allowing the filling process to continue without altering the shape of the structure. The upper stiffener with internal steel reinforcement bars acts to compress the upper part of the structure to prevent ripples from forming during the first stages of filling and compaction and as a load dispersion device that helps to distribute the vertical loads in the structure , thus reducing the minimum overload requirement. The upper stiffener in the length direction of the structure stiffens the upper portion of the arch using cut-off pins to structurally connect the concrete beam to the steel arch to provide a positive bending resistance in the upper part of the arch. This multi-component stiffener moves towards a structure that allows the use of a reduced overload but can not provide a large reduction in the thickness of the overload or for very large spaces in the design of the arcs. The main reason is that the Fisher's top stiffener is not designed to withstand the negative bending moments typically found in the skirt portions of low-rise roof arches and wide-spaced arches. The purpose of the transverse members separated between the upper stiffener and the lateral supports is to provide some rigidity to the structure to avoid distortion during the filling step. These are not members designed to resist negative moments. In addition, since an installed flexible arc structure is subjected to positive bending moments in the corona under live load conditions, it undergoes negative bending moments in the same location during filling when it receives pressure from the sides and top It is distorted by the spikes. In Fisher's upper stiffener, since it is designed to take advantage of a cutting link connection between concrete and steel to resist positive bending moments in the upper portion of the arch, negative bending moments in the same region during the filling is simply resisted by the provision of reinforcement bars on top of the concrete slab, thus requiring in situ training and bar work, adversely affecting construction costs. In the same way, since the upper stiffener and the lateral supports have significant sizes, the weight of the finished structure is substantially increased.

In Sivachenko, U.S. Patent 4,786,541, a method of forming corrugated steel plates of flat plate storage for use in construction, among other things, metal arc structures is disclosed. The specific reference was made to the additional strength advantage of a double corrugated plate configuration where the plates are joined along opposite channels, either directly or with spacers between them. It is noted that the double plate assembly can be hollow or can be filled with concrete or a similar material. The concrete between the plates can be reinforced with conventional reinforcing steel bars that can be oriented parallel to the corrugations of the plates. It is evident that when the concrete is placed between the plates without reinforcement, it will only act as a filler and will not improve the strength characteristics of the assembly. Even when the concrete is supplied with reinforcing re-bars, the bars are not designed for the connection of cutting link between the concrete and the corrugated steel plates and with the assembly is subjected to flexing, the concrete and the steel plates work independently of each other. Such a system is moved towards a stiffening method of a corrugated metal plate structure by the use of a double plate assembly with a typical concrete filling center and a sandwich type support structure. In the case of a buried arc structure with multiple curves, the installation of the re-bars according to Sivachenko will become an even more difficult task. In the patent of the U.S.A. 5,326,191 reinforcement of the continuous corrugated metal sheet is ensured until at least the crown of the culvert extends continuously along the culvert. This culvert design solves the problem associated with transverse reinforcement separated from the prior art and is inherently capable of resisting positive and negative bending moments. However, continuous reinforcement in wide interval structures can be prohibitively expensive and difficult to install.

BRIEF DESCRIPTION OF THE INVENTION The concrete reinforced corrugated metal arch type structure of this invention faces several of the above problems. Mixed concrete and metal beams, when provided by this invention, improve the strength of the structure at the moments of positive and negative bending induced in the structure by the low height overload that supports live heavy vehicle traffic or during the filling of the arch type structure. Each cavity filled with continuous concrete defined by interconnecting an upper plate and a lower corrugated plate of this invention will act as a concrete beam covered with mixed metal that functions as a curved beam column stiffener with, friction moment and capacities of axial load to provide greater design flexibility in the arc structures provided with low height overload. According to one aspect of the invention, a reinforced corrugated metal arch structure of mixed concrete comprises: i) a first set of corrugated metal plates formed, interconnected in a manner to define a base arch structure of a cross section of defined interval, height and length; the base arch having a crown section and apron sections appended to the interval cross section and the corrugated metal plates of defined thickness having corrugations extending transversely from the length to provide a plurality of columns of curved beams in the base arch; ii) a second series of metal plates formed, interconnected in a manner to cover and contact the first set of interconnected plates and the base arc, the second series of interconnected plates extends continuously in the transverse direction to include at least one corona of arc and securing directly to the first set of interconnected plates; iii) the interconnected series of the second plates and the first set of plates defining a plurality of individual cavities, transversely extending, continuously covered, each cavity being defined by an inner surface of the first set of plates and an opposite inner surface of the second series of plates; iv) the concrete filling of each continuous cavity from end to end of the cavity as defined by the transverse extension of the second series of plates, the cavity filled with concrete defines an interface of the concrete covered by the metal interior surfaces of the second interconnected series of plates and first set of plates; v) the interior surfaces of the cavity for each of the first and second plates having a plurality of shear bending connectors at the mixed concrete / metal cover interface, the mixed shear connectors are a rigid part of the First and second plates to ensure that the concrete and the metal act on the unisomno when a load is applied to the arc structure, the shear bending connectors provide a plurality of curved beam column stiffeners to improve the bending strength and the combined positive and negative axial load resistance of the base arc structure, there being a sufficient number of the second series of plates to provide a sufficient number of curved beam column stiffeners to withstand the anticipated loads imposed on the structure.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention are described with respect to the drawings in which: Figure 1 is a perspective view of a re-entrant arch structure in accordance with an aspect of this invention; Figure 2 is an end view of the structure of the bridge of Figure 1; Figure 3 is a section along line 3-3 of Figure 1; Figure 4 is a section along line 4-4 of Figure 1; Figure 5 shows an alternative embodiment for the cutting connectors of Figure 3; Figure 6 is an enlarged view of a cutting connector secured to the inside of one of the corrugated plates; Figure 7 is a section similar to Figure 3 showing a socket for introducing concrete into the cavity; Figure 8 is a section of the corrugated plate having an alternative embodiment for the cutting section devices; Figure 9 is a section of the corrugated plate showing another alternative embodiment for the bending cutting devices; Figures 10, 11, 12, 13, 14, 15 and 16 are sections through the first and second corrugated plates showing alternative modalities for the second series of plates in relation to the first set; Figure 17 is a section through a prior art structure having a relief slab; and Figure 18 is a section through the prior art structure having superior reinforcement and support reinforcements.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES In accordance with the present invention, a wide interval arc type structure is provided wherein the structure is constructed of corrugated steel plates. The broad range is intended to encompass, according to the preferred embodiments, the arc intervals in excess of 15 m and most preferably in excess of 20 m. The structure of this invention with intervals of this scale can withstand large loads, such as loads of heavy vehicular traffic with a minimum overload cover and do not require a concrete reinforcement earthenware or any other type of voltage reinforcement or distribution devices. above the arch structure. It is understood that the arc structure of this invention can be used for lower ranges where they dictate the particular specifications, or taking into consideration the characteristics of the structure of this invention, the substantially thinner steel plate can be used. Alternatively, other lower strength metals can be substituted for steel such as aluminum alloys by improving the load carrying characteristics of the preferred structure. With reference to Figure 1, one aspect of the invention is described as being used in an arc type structure commonly referred to as a re-entrant arc. It is understood that the structure of this invention can be used with a variety of corrugated arch type designs including ovoids, box culverts, round culverts, elliptical culverts and the like. The structure 10 has a range, as indicated by line 12, and a height, indicated by line 14. The cross-sectional shape of the arch in combination with a height dimension and an interval dimension, defines the relief cover for the arch structure that is designed to accommodate the uneven traffic such as cars, trucks, trains and similar. Alternatively, the arch 10 can be used to bypass a river or other type of water passage. The base portion 16 of the arch is placed on suitable foundations in accordance with standard arc engineering techniques. The arch 10 is constructed by interconnecting a first set of corrugated steel plates formed generally indicated by the numeral 18, wherein the joint is defined by the dotted line 20. The first set of interconnected plates defines the base arch structure providing the cross section interval 12 and height 14 desired. The direction of arc length is indicated by line 22, which determines the number of interconnected plates needed to provide the desired arc length. The arc length is mainly determined by the upper step amplitude. The first set of corrugated interconnected plates having the individual corrugations provide a corresponding plurality of curved beam column. Each corrugation 21 is transverse in the arc functions as a curved beam column that resists the moments of positive and negative bending in the axial load in the structure of the base arc. As will be shown in more detail with respect to Figure 3, the plates are of corrugated metal, preferably steel, of a defined thickness having ridges and channels extending transversely of the length 22 of the arch. The channels of the second set of plates are secured to the ridges of the first set of plates. According to this particular embodiment, the second set of plates ends at 26 where the lines 28 indicate the joining of the second interconnected set of plates. As will be described with respect to Figure 2, the second set of plates can extend the total cross section of the arch to a larger portion thereof depending on the design requirements of the arch by providing suitable stiffeners for the curved beam columns of the structure. of base. The second set of plates extends over an effective arc length to support the load. It is understood that by providing overload, depending on the angle of repose or shape of the sides of the overload, a portion of the base arc can extend beyond the overload and since it is not supporting any load, it does not require a second set of plates in said region of the crown and / or skirt sections of the base arch. As will be described in more detail with respect to the following figures, the cavities defined between the ridges in this embodiment of the second plates and the channels of the first plates, which extend from the termination section 26 for each region of the skirt of the arch, they are filled in by completing the open end of each cavity with an appropriate outlet 30. The holes 32 are then formed in the crests of the upper plates to allow the injection of concrete into the covered cavity, as indicated by arrow 34. It is understood that several holes 32 can be provided along the cavity to facilitate the injection of the concrete to fill the cavity and prevent the formation of voids in the cavities so that a suitable mixture, steel and concrete interface is provided, as will be described in Figures 3 and 4. Once the cavities are filled with concrete, the openings 32 are optionally connected with suitable taps 36. The arc 10, as shown in Figure 2, is of a reentrant arc design having a crown section, as defined by the arc 38 and opposite skirt sections, as defined by the respective arcs 40. The first set of plates 18 defines the base arch extending from the foundation 42 suitable to a first end 44 to the second end 46 provided in the foundation 48. The second set of plates 24 extends continuously over the crown section 38 and on the portions of the skirt sections. The extension of the second set of plates in the portions of the skirt section 40 depends on the requirements of the design. According to this embodiment, the second set of plates 24 extends over a large part of the skirt section above the surface 50 of unevenness. It is understood, however, that the second set of plates can be extended to the base portions 44 and 46 of the arch or can extend only to the skirt sections depending on the design requirements to withstand the positive and negative bending moments. and the axial loads. As shown in Figure 2, the lines 20 indicate the connection region of the first set of plates and the lines 28 indicate the interconnection of the second set of plates. When a highway is provided through the arch structure, Highway 50 is constructed in accordance with the standard highway specifications. The foundations 42 and 48 are placed in the compact filler 52. Above the compact padding is a layer of compact granular material 54. Expressway 50 can be a layer of reinforced concrete and / or compact asphalt 56. Interval 12 and height 14 are selected to define a sufficient draft cover to allow the designated vehicular traffic, the passage of water or the like to pass under the arch 10. Above the arch 10, the area is filled with compact filler 58 having a relatively minimal overload in the region 60. Normally with the interval steel structure broad, the concrete discharge slabs or the like, as will be described with respect to Figure 17, are positioned to support in conjunction with the steel arch 10 the heavy live loads as the vehicular traffic on the upper surface 62. With the structure of this invention, such discharge slabs or other forms of concrete reinforcement in the upper part of the crown section 38, as shown in the figure 18, are not needed where a minimum amount of overload 60 is required. This is significantly beneficial in designing the upper surface 62 because the tilt of the access 64 is greatly reduced. The upper surface 62 is constructed in the normal manner where the section 66 has the usual compact layer of granulated material and an upper layer of concrete and / or asphalt. According to this invention, by providing continuous curved stiffeners extending transversely in circumferential shape, defined by the discrete contained cavities, said structure provides a reinforced arch supporting a heavy live vehicular traffic load in the overpass 62. The concrete covered metal in the cavities Discrete, defined between the first and second plates, provides a mixed arc structure of unified design to resist bending and axial loads superimposed on the arc structure. The mixed reinforcement stiffener of this invention is provided in the contained cavity defined by the coating of the first and second set of plates 18 and 24. As shown in section 3-3 of figure 3, the corrugated steel plate of the first set defines a channel 68 as opposed to a ridge 70 of the second plate. According to this particular embodiment, the first and second corrugated plates have a sinusoidal corrugation that is identical for the first and second plates 18 and 24. The first and second plates are interconnected where the apex of the ridge 72 of the first plate is it contacts the apex of channel 74 of the second plate. The plates can be secured in this region by various types of pins. Preferably, the use of screws 76 that extend through the aligned openings and the first and second plates are secured by suitable nuts 78. The cavity 80, as defined by the inner surfaces 82 of the first plate and 84 of the second plate extend from the terminating ends 26 of the second plates in a continuous transverse shape of the arch. The concrete 86 fills the cavity 80 to define a mixed interface 88 at the junction of the concrete 86 with the internal surfaces 82 and 84 of the respective plate walls 90 and 92. When the arc structure is loaded, the metal / concrete interface acts in a form of mixed reinforcement by means of the devices 94 provided on the internal surfaces 82 and 84 of the first and second plates that provide a cutting bend at the interface 88, between the metal plates 90 and 92 and concrete 86. The cutting resistance of the devices 94 is selected depending on the design requirements of the arc bridge 10. It is understood that the cutting connector device 94 may be integral with the plates 90 and 92 or be secured thereto by resisting cutting at the interface 88. According to the particular embodiment of Fig. 3, the cutting connecting devices 94 are individual bolts 96 secured to the inner surfaces 82 and 84. In this particular embodiment , the bolts 96 are secured to the apex 98 of the channels 68 and the vertex 100 of the ridge 70 of the second set of plates. Said locating of shear bending connectors improves the strength of the curved beam by providing a cutting flexure in the external and internal fiber of the stiffener where the cutting tension is at maximum during bending. The strength characteristics of the individual adjacent curved stiffeners is shown in more detail in Figure 4. The first and second plates 18 and 20 define the continuous concrete cover 86 to provide a mixed concrete / steel member through the cutting connectors. 96. The cutting connectors 96 ensure in the mixed interface 88 that the concrete and steel act in unison when a load is applied to the structure. With this design, according to the invention, the improved stiffeners in the arc can withstand the moments of positive and negative bending in the arc caused by the movement of higher loads such as the vehicular traffic load. Other designs can not be inherently provided in the structure positive and negative significant bending resistances. Other designs require the use of relief slabs or steel bars reinforced above the structure to reduce or provide a positive and negative bending resistance. Other benefits flowing from the mixture according to this invention is that there may be a reduction in the thickness or weight of the metal used in the construction of the first and second plates. Metals other than steel, such as aluminum alloys, can be used in the plates. The steel stiffeners, mixed concrete adjacent adjacent can also accommodate considerably higher intervals and have a reduced deflection, but more importantly, allow the use of a lower overload in the arc design, since they require less experience in filling operation of the arch structure or alternatively are capable of accommodating a lower grade filler material. The provision of the first and second plates connected in a manner to define the cavities contained for the concrete greatly facilitate the lifting of the structure by providing greatly increased intervals for the structure, as will become apparent from the following examples when analyzing the comparative resistance of the construction. To ensure that the concrete in the cavity 80 functions as a mixed support structure, as shown in Figure 4, the cutting connector bolts 96 are separated from one another by engaging the respective channels 68 of the first plate and ridge. 70 of the second plate. In addition, the opposing sets of bolts alternate in relation to each other to optimize the cutting flexure at the interface 88 of steel and concrete. As shown in Figure 5, an alternate arrangement is provided for the bolts 96 connectors. The channel 68 has sides 102 with downward inclination and the ridge 70 has sides 104 with upward inclination. The bolts 96 cutting connectors are then positioned on said sides with downward inclination of the channel and the sides with upward inclination of the ridge to thereby increase the number of connecting bolts within the cavity 80 while at the same time provides a desired space in the direction that extends transversely of the cavity. With reference to Figure 6, the preferred pins 96 with a portion 106 and an elongated head portion 108, have their strength in base portion 110 welded to the first wall 90 of steel plate. According to this embodiment, the resistance welds 112 consume some base metal 113 when connecting the cutting pins 96 in place. The section of figure 7 shows the cavity 80 which is filled with concrete 86 through a take-off nozzle 114. The take-off nozzle has a coupling 116 which is secured to the wall 92 of the plate 24. The coupling has an opening 118 where the concrete is injected into the cavity 80 in the direction of the arrow 120 by connecting the concrete pump line to the coupling 116. Once the filling of the cavity with the concrete 86 is completed, a suitable socket 124 is provided. it can pass through the coupling to close the opening 118 to complete the installation of the concrete. It is appreciated that other techniques can be employed to fill the cavities with concrete to adapt the end of the concrete pump line with a releasable coupling that is momentarily connected to an opening in the wall 92 of the plate for filling purposes and then removes and a plug or the like is secured to the opening of the plate 92. As previously described, various types of shear bending devices can be formed on the inner surfaces of the first and second plates. Figure 8 shows separate cut bending connectors 126 formed in the wall 90 of the plate of the first plate 18. The integral cut bending connectors are preferably formed along the apex of the channel 98. The connectors 126 can be stamped in the wall 90 of the plate and projecting in with defined peaks 128. Since the concrete places the integrally formed peaks 128 projecting inward into the cavity, it provides the necessary cutting flexure with the inner surface 82 of the plate. Similarly, with the alternative embodiment of Figure 9, the first plate 18 has formed on its inner surface 82 a plurality of protrusions 130. The protrusions 130 are formed integrally on the inner surface and have a sufficient depth to provide a cutting flex with the concrete when it is pumped and placed inside the cavity of the assembled structure. Figures 10, 11 and 12 show alternative arrangements for the first and second plates to provide several spaces for the curved beams in the length direction of the arch. In Figure 10, the base of the arch is provided by a plurality of interconnected plates 18. At the selected positions along the base of the arch, a series of second plates 24 is connected to position the channel 68 opposite the ridge 70. of the second plate when defining the cavity 80. One or more of the channels 68 can be skipped with the second series of plates 24 to thereby provide separate arc stiffeners interconnected by the corrugations of the base plates 18. Alternatively, as shown in FIG. shown in Figure 11, the second series of plates 24 may include multiple corrugations, providing multiple ridges 70 and thus multiple cavities 80. One or both of the multiple cavities in each series of the second plates 24 is filled with concrete as shown in FIG. indicated by shear bending connectors 96. With the structures of Figures 10 and 11 the curved stiffeners carry the load where the corrugations of the base plates 18 interconnect these beams to provide a unitary structure. It is appreciated that depending on the anticipated or designed loads, the spacing of the beams can be determined in this way to provide the necessary positive and negative bending resistance and the axial load resistance throughout the structure. It is also appreciated that the second plate 24 may have 3 or more coars. However, for a steel plate 75 cm wide, of a thickness of approximately 3 to 7 mm, it is difficult to form more than 2 corrugations of sufficient depth and distance. Alternatively, if an aluminum plate 120 cm wide is used, it is possible to provide at least three and up to four corrugations because the aluminum is easier to form. With the embodiment of Figure 12, the series of second plates 24 is continuously provided in the base plates 18. The plate assemblies are interconnected by screws 76 where some locations of up to 4 plate thicknesses are interconnected. Although this complicates the assembly, the resulting structure having each adjacent cavity of the first and second opposed corrugated plates filled with concrete provides a firm structure to optimize the positive and negative bending resistance and axial loads in the arch when supporting the Superimposed loads or support the structure during filling. One of the advantages in the structures described with respect to figures 10 and 11, is that the series of interconnected second plates do not overlap, thus avoiding situations where up to 4 plate thicknesses have to be interconnected, as with the embodiment of Figure 12. Figures 13 and 14 show alternative modalities with respect to the distance variation of the corrugation in the first and second plates in relation to each other. In Figure 13, the second plate 24 has a distance to the sinosoidal corrugations where the ridges 70 are separated 1/2 away from the channel 68 of the first plate 18. This arrangement provides less corrugations in the first plate, which it can be of a material thicker than the second plate that has a greater number of corrugations per unit width of the second plate. The cutting flex connectors 96 are provided in the cavities 80 in the manner shown to form the curved beam stiffener to reinforce the base arch structure. Alternatively, as shown in Figure 14, the second plate 24 may have fewer corrugations than the first plate 18. In essence, it is the opposite of the cross section of Figure 13, only that the depth for the first and second plates is increases, as indicated by the distance between the screws 76. As with the embodiment of Fig. 13, the cut-off connectors in the form of bolts 96 are provided in the cavities 80 to provide the metal and mixed concrete stiffeners. It is evident from Figures 13 and 14 that the cavity 80 can take a variety of cross-sectional shapes when forming the concrete stiffener covered in mixed metal. Another alternative is shown in Figure 15, wherein the second plate 24 has a polygonal shaped corrugation, which according to this embodiment, has a square shape, although it is understood that the second plate 24 may have other shapes of polygons, such as a triangular trapezoidal and the like. As with the other embodiments, the cutting pin connectors 96 are provided in the cavities 80 to form the mixed and desired concrete metal stiffeners in the reinforcement of the base arch structure. With the arrangement of Figure 15, the second plate 24 with the polygonal shaped corrugations allows a greater amount of concrete to be found above the plane of the ridges of the first plate 18. The arrangement of Figure 16 provides a second plate 24 flat connected to the first plate 18. At this point, the flat plate 24 is in the plane defined by the vertices of the ridges 72 of the first plate. The cutting pin connectors 96 can be provided in the cavity 80 in the manner shown where each of the cavities 80 can be filled. The use of a second flat plate in the series of second plates facilitates the special shapes that can be necessary to cross the arch, for example, in regions of the arch where the radius of curvature is relatively small, the second flat plate 24 may be bent further to engage the curvature of the first plate 18. With the various embodiments of the figures 10 to 16, it is evident that the design of the cavity in the cross-sectional shape can vary greatly. It is understood that by providing the most efficient form of mixed concrete metal stiffener for bending moment resistance, that the cavity should extend above and below the plane of the ridges of the first plate to thereby define the greater possible distance between the external and internal fibers of the stiffener, that is, the greater section module for the stiffener. At this point, the preferred shape for the first and second plates is the one described with respect to Figures 10 to 12, wherein the opposing ridges of the second plate are separated as much as possible from the opposite channels of the first plate to carry the maximum in this way the section module of the individual mixed metal and concrete stiffeners. A surprising benefit flowing from the various embodiments of this invention in providing the stiffeners is that the intervals of the structure can be greatly increased over the traditional types of steel arch structures having other types of stiffeners. By providing a unique curved stiffener of mixed metal and concrete material that has a cutoff bend at the interface, very significant modifications can be made to the arch design to provide new clearance covers. None of the prior art structures allows modification of the standard arch design because such standard arch designs have restricted shapes that were believed to be only ways to resist bending moments in the structure. When the second series of plates extends from the base of one side of the arch to the base of the other side of the arch, the increase in combined axial and bending capacity will extend through the entire arch structure. Such unique mixed curved beam columns where the concrete is covered with metal allows the design engineer to provide unique shapes to the curved structure to provide different types of relief covers, minimal overload and less marked access inclinations. Normally, such alternative designs can not only be achieved with fully reinforced poured concrete bridge structures. The structural features of this invention therefore take the standard type of arc design for corrugated metal components in a completely new area by providing alternatives for expensive fully reinforced standard concrete bridge designs. Another benefit that flows from the capacity to the new design ridge covers for the arch structure is to provide regions under the arch, but outside the upper passage area of the clearing deck, whose regions function as water passages, sidewalks, drainage, auxiliary access for pedestrians, animals, and less vehicular traffic such as bicycles. Although spaces for these additional features can be provided in more expensive formed concrete bridges, the metal arc type structure of this invention fulfills these characteristics at a considerably lower cost. The following description of the prior art standard structures of Figures 17 and 18 in combination with the following structural analysis of said standard structures together with that of the new arc structures reveal many significant benefits of the new design. A superimposed localized load, like live vehicle load, will generally create two types of stresses in a flexible arc structure. Figure 18 shows the typical deformation 154 suffered by an arch structure 146 of the U.S. patent. 4,390,306 under a localized load. Due to the downward load 148 on the crown 150 of the structure, positive bending moments 152 are created in the crown portion of the structure and negative bending moments 154 are induced in the skirt portions. This particular design attempts to resolve the positive bending moments by providing a slab 155. However, the bras 158 do nothing to resist the negative bending stresses in the skirt portions, because the structure can flex in that direction. The vertical live load will also find its way into the fiber in cross section of the structure that transmits the vertical axial load 159 to the foundation 156 of the structure. The ratio of the bending stresses to the vertical stresses in said structure for a defined vertical load varies according to the thickness of the overload. Generally, the thinner the overload, the more localizable the live load will become when it reaches the surface of the arc structure, the more deformation occurs in the roof, the higher the bending stresses in the structure. The arches 132 of standard flexible corrugated metal of Figure 17 are particularly weak in the strength of the flexural stresses. Traditional design tends to limit the amount of flexure in the structure by trying to disperse as much as possible localized live load 134 in the structure. The most obvious way is to increase the thickness of the overload floor 136. A load point acting on the overload floor will be distributed in the thickness of the floor according to the voltage distribution cover 138 as shown in the dotted line in figure 13. When the load reaches the crown surface 140 of the metal arc shell, a load will act on a wide area of the shell surface. The greater tension in the structure therefore becomes axial tension rather than bending stress. In the traditional buried arc flexible design, a standard minimum overload cover must be provided. In a situation where the thickness of the overload is limited and is less than the minimum requirement, a voltage discharge slab 142 should be provided to further expand the voltage distribution cover 144 above and outside the structure. The voltage discharge slab 142 can be positioned in the upper part of the arc 132, in the surface 135 or in any intermediate position. Since the slab 142 is positioned near the top of the arch, the shape of the voltage distribution cover will obviously change. In any case, the amount of concrete used in the stiffener design of this invention is considerably less than that which has to be used in a discharge vessel. The following engineering analysis demonstrates the surprising benefits derived from the design of this invention. A mixed structure was designed of corrugated metal arch type reinforced with concrete of the type shown in figures 1 and 4. The first set of corrugated metal plates formed was made of 3 ga of steel thickness in a re-entrant base arch profile with an interval of 19,185 m and a height above the foundation of 8,708 m. A second series of formed corrugated metal plates made of 3 ga of steel thickness was interconnected in a form to cover the first set of interconnected plates of the base arch.

The second series of plates was installed in segments with two corrugations extending transversely from the length of the arch with the channels of the corrugation of the second series of plates secured to the ridges of the first set of plates as shown in figure 11 Prior to the zinc coating, the cutting pins, as shown in Figure 1, were coupled with resistance welds to the first and second set of corrugated metal plates. The cutting bolts are 12 mm in diameter by 40 mm long and 800 mm in the center. The cutting pins alternate between the first and second plates, as shown in Figure 4. A take-off nozzle is provided in the crown of the second set of plates, as shown in Figure 7, the concrete filling with a 25 MPa compressive strength was introduced into the cavity through the intake nozzle after the ends of the cavity had been connected. Site conditions required a deck height for this 1.13 m structure, while contemporary bridge design standards required a minimum deck height of 3.82 m with a non-mixed metal arch structure. In order to achieve the height of 1.13 m of roof, a non-mixed metal arch structure will require the use of a 1 ga thick steel for the first set of formed plates and a 1 ga thick steel for the second set of reinforcement plates. The non-mixed metal arch did not have a concrete fill void and had no cutting bolts. However, it required a concrete relief slab 300 mm thick by 20 wide extending the entire length of the structure installed on the road surface. The reinforced mixed concrete structure of this invention was able to meet the design requirements for the relatively low minimum value of overload without the prior problems of the prior art structures. The reinforced corrugated metal arch structure of mixed concrete reinforcement provides considerable savings in material and manufacturing costs. The cost of steel 3 ga thick with a bolt was considerably less than the cost of a 1 ga thick steel without bolts cutting. In addition, the amount of concrete to fill the voids was considerably less than the amount of concrete used to build the relief slab. It is estimated that the cost of the unreinforced corrugated metal arch structure together with the concrete relief slabs is at least 20% more than that of the mixed structure of the present invention. The present invention overcomes the problems associated with live loads in arch structures with low roofs by increasing the bending moment capacity of the arch structure in the crown and skirt portions. The provision of a continuous curved stiffener in the structure allows the structure to resist the moments of positive and negative bending. In addition, during the stage of installation of the structure, the worsening in the crown portion could occur due to the soil pressures acting on the sides. In this situation, negative bending will occur in the crown portion of the structure, which the concrete / metal composite arc structure of the present invention is equally capable of resisting. This presents a significant advantage in any prior art which is designed primarily for the limited strength of the positive moment and which is not able to withstand the negative moments simultaneously without elaborate further reinforcement means. In addition, by increasing the bending moment capacity in a curved beam column subjected to combined bending and axial loads, the combined axial and bending load capacity of the column is also increased. Although the preferred embodiments of the invention are described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.

Claims (9)

NOVELTY OF THE INVENTION CLAIMS

1. - A reinforced corrugated metal arch structure of mixed concrete comprising: i) a first set of corrugated metal plates formed interconnected in a form to define a base arch structure and a cross section of defined interval, height and length, said base arc has a crown section and appendage sections attached for said interval cross section and corrugated metal plates of defined thickness having corrugations extending transversely of the length of said arc to provide a plurality of curved beam columns in said base arc; ii) a second series of metal plates formed interconnected in a shape to cover and contact the first set of interconnected plates of said base arc, said second series of interconnected plates extending continuously in the transverse direction to include at least said crown of arch and securing directly to said first set of interconnected plates; iii) said interconnected series of second plates of said first set of plates defines a plurality of individual cavities, which extend transversely and are continuously covered, each cavity is defined by an inner surface of said first set of plates and an opposite inner surface of said second series of plates; iv) the concrete filling of each cavity continues from the end of the cavity to the end as defined by the transverse extension of said second series of plates, said cavity filled with concrete defines an interface of said concrete covered by the interior surfaces of metal of said second interconnected series of plates and first set of plates; v) said inner surfaces of said cavity for each first and second plates have a plurality of shear bending connectors in said mixed concrete-covered metal interface, said mixed shear bending connectors being in a rigid part of the first and second plates to ensure that the concrete and metal act in unison when a load is applied to said arc structure, said shear bending connectors provide a plurality of curved beam column stiffeners to improve the combined positive and negative bending strength and the axial load resistance of said base arc structure, there being a sufficient number of said second series of plates to provide a sufficient number of said curved beam column stiffeners to withstand the anticipated loads imposed on said structure.

2. An arc type structure according to claim 1, further characterized in that said second series of plates is flat.

3. An arc type structure according to claim 1, further characterized in that said second series of plates are corrugated metal plates with at least one corrugation, said corrugation of said second series of plates extends transversely from the length of said arc with channel portions of the second corrugated plate secured to the crest portions of the first set of plates.

4. An arc-type structure according to claim 3, further characterized in that said series of plates has a number of corrugations per plate unit width, greater than the number of corrugations for the same unit width of said first plate. .

5. An arc-type structure according to claim 3, further characterized in that said corrugations are round or polygonal in cross-sectional shape. 6 An arc type structure according to claim 3, further characterized in that said series of plates extends the range of said arc from a base portion of one of the skirt sections in said crown section to a base portion of the other of said skirt sections. 1 . - An arch type structure according to claim 3, further characterized in that said second series of plates extends over a greater portion of said structure range from a middle region of one of said skirt sections in said crown section to a middle region of the other of said skirt sections. 8. An arc-type structure according to claim 6, further characterized in that said structure is an ovoid culvert, a re-entrant arc, a box culvert, round culvert or elliptical culvert. 9. An arch type structure according to claim 7, further characterized in that said structure is an ovoid culvert, a re-entrant arch, a box culvert, a round culvert or elliptical culvert. 10. An arc-type structure according to claim 1, further characterized in that said shear bending connectors in said mixed interface comprise a plurality of integrally projecting ears formed on said first and second plates to resist movement. relative between said concrete and said first and second set of metal plates. 11. An arc type structure according to claim 1, further characterized in that the shear bending connectors in said mixed interface comprise inwardly projecting bolts secured to said internal surfaces of said cavity defined by said first set of plates and said series of second plates. 12. An arc type structure according to claim 1, further characterized in that said shear bending connectors in said mixed interface comprise the protrusion formed on the internal surfaces of said first and second plates. 13. An arc type structure according to claim 3, further characterized in that each series of plates has a single corrugation. 14. - An arc-type structure according to claim 3, further characterized in that each second series of plates has multiple corrugations to define a plurality of cavities that extend transversely adjacent, at least one of said adjacent cavities has said connectors cutting flexure and are filled with concrete to provide said curved beam column stiffener. 15. An arc type structure according to claim 14, further characterized in that each of said adjacent cavities has said shear bending connectors and is filled with concrete to provide adjacent groups of said curved beam column digidizers. 1

6. An arc type structure according to claim 3, further characterized in that a second set of corrugated plates covers said first set of plates, said second set of plates continuously covers in the longitudinal direction said first set of plates for a length that effectively supports the load, the selected cavities have said shear bending connectors and are filled with concrete to provide said sufficient number of said curved beam column stiffeners. 1

7. An arc type structure according to claim 16, further characterized in that the adjacent cavities have said shear bending connectors and are filled with concrete to provide the curved beam column stiffeners at said effective length of said structure. which supports the load. 1

8. An arc-type structure according to claim 15, further characterized in that said corrugated plate of each said first and second set of plates has the same sinosoidal profile by means of which each cavity is defined by adjacent ridges of said first set , screwing to align the adjacent channels of said second set. 1

9. An arc type structure according to claim 18, further characterized in that said bending and cutting connectors comprise bolts projecting inwardly secured to said internal surfaces of each cavity, said bolts are interspersed along opposite internal surfaces of said first and second plate assemblies. 20. An arc type structure according to claim 19, further characterized in that said corrugated plate has a sinusoidal corrugation profile of a selected depth of 25 mm to 150 mm and a selected distance of 125 mm to 450 mm. 21. An arc-type structure according to claim 20, further characterized in that said interval exceeds 15 m. 22. An arc type structure according to claim 21, further characterized in that the sockets are provided at each end of the cavity. 23. An arc-type structure according to claim 22, further characterized in that said cavity is filled with concrete through a plurality of holes in said second series of plates, each hole is covered after the filling is completed of concrete of each individual cavity.