NZ203069A - Modular hollow conduit of segmental components:flattened base:laterally adjacent components varying in curvature,material or thickness:methods of use - Google Patents

Description

203069 Priority Date{s): J J.6. % P./.3 3. ? Complete Specification Filed: ( '. /.S3 Cfass: Jf. (t?.^. .67.03£Z/QQy £~.Q3F.3JQQ;.. JE.O.O. H3.J< D.J... £?AQJ.Qj.Q.Q:t. £3JDJJ.J.QQs.3Q(3£> Publication Date: ... .^-1.

P.O. Journal, No: ^c^SST.

Patents Form No. 5 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION "HOLLOW STRUCTURES AND METHOD OF PRODUCING HOLLOW STRUCTURES" I/WaK MARCEL MATIERE, a French citizen, of avenue Aristide Briand 15000 Aurillac, France, hereby declare the invention, for which i/wk pray that a patent may be granted to me/atsc, and the method by which it is to be performed, to be particularly described in and by the following statement:- 203069 FIELD OF THE INVENTION The present invention relates to a method for producing hollow structures of cylindrical or a similar concave configuration bearing on the ground along one of its generatrices.

Such structure are typically large cross-section conduits, for example large.r than the conventional indus- 2 trial fabrications of about 2 m , which may or may not be underground, for carrying water or other fluids, which may or may not be pressurized, or even for ducts for cables or passageways for pedestrian or vehicular traffic or standing.

The invention is also applicable to small cross- 2 sectional area conduits, for example up to 1 m . It is also applicable to the production of structures of similar configuration but relatively short in length for use as cellars, silos or bomb shelters.

Although the invention is essentially described with reference to large cross-sectional area conduits it is not limited to such a technical field.

PRIOR ART Various techniques are used for laying or installing conduits for, inter alia carrying water, transporting petroleum products, or carrying cables or other conduits.

The most commonly used technique comprises utilizing tubular sections of circular cross section which are assembled end to end by various methods. This technique has drawbacks which increase with the diameter of the conduit even if the lengths of the sections are shortened, viz., manufacture, transportation, handling and installation In any event, other than the problems of fabrication, pro blems of shear size are posed once you reach an outer diameter of 2.5 m which corresponds to the normal limit for road transportation. For carrying very large quantities of fluids a plurality of parallel conduits must be provided, which is an expensive solution, or the conduit may have to be fabricated at the construction site in accordance masonry construction techniques or work carried out in underground galleries which is also expensive and time-consuming for fabricating or building.

Moreover, as is known, conduits of circular section are best adapted to high internal pressures. Such a cross section is the easiest to produce when sections corresponding to the entire cross-section or contour of the conduit are fabricated. On the other hand, such a circular cross section has drawbacks for other uses. A conduit of circular cross section produces stresses in the bearing ground having a pronounced maximum in the median region. Consequently, if the soil is loose,considerable differential subsidence may occur after the conduit is laid. Circular cross sections are poorlysuited for good use of crowded space in an urban environment. Finally, the weight of the conduit is comparatively high; indeed, the constituent material is in the case of unitary sections covering the entire cross section or contour uniformly distributed along the entire periphery whereas the stresses are not so distributed.

To overcome these various problems it has been proposed, to construct conduits having cross sections flattened at their base by assembling on site previously prepared longitudinal members, each corresponding to a part of the contour or cross section of the conduit and made of corrugated sheet metal. Such structural components have a low mechanical 5 strength with, respect to external forces so that one is unsure of maintaining the contour and the fluidtightness of seals. Further, the corrugations increase flow resistance .

U.S.. patent 2,400,0 71 10 disclos techniques consisting in assembling a large number of small dimension components each having a transverse flange for assembling adjacent components. The large number of components means they have to have identical configurations which leads to adopting a cross section of circular 15 contour and in this case the stress resistance requires that the junctions alternate in the longitudinal direction. U.S. patent 2,400,0/1 provides taking into account the stresses exerted on the conduit wall and using for the upper part of a tunnel, components having lower strength 20 than those for the lower part. Yet an assembly of alternating joints of components of different characteristics is of uncertain strength and in addition this introduces a 1 j further complication in the assembly of a great number of small components which is difficult to execute satisfacto-25 rily with unskilled workers.

OBJECT AND SUMMARY OF THE INVENTION Thus, it appears that there is an unsatisfied want for a method for producing cylindrical hollow structures or the like bearing on the ground along a generatrice having cross-sectional shape with a flattened base, in particu-v*- SI i' 2 9 NOV 1985 jj .4?/ A- 203069 lar large cross-sectional area conduits, which method produces structures having a high mechanical strength, and fabrication, transportation and installation costs considerably reduced with respect to current techniques.

According to one aspect of the invention there is provided a method for producing an elongate hollow body in the form of a cylinder bearing on the ground along a flattened base by assembling and joining on site a series of modules formed of previously prepared longitudinal segmental components each corresponding to a part of the cross section of the hollow body, said components bearing one another along longitudinal joints, in which the inner surfaces of the adjoining components are flush said method comprising preparing at least two types of components, in cross section, respectively a lower component with a flattened base and an upper component, at least one structural characteristic of said laterally adjacent components, selected from the curvature, the thickness and the material, being different and then forming a module by first positioning the lower component and then the upper component and assembling said components together so as to permit limited relative displacement therebetween and assembling adjacent modules one to the other along transverse joints so as to permit limited relative displacement therebetween and then after stabilizing the surrounding ground and the completed hollow body, assembling the adjacent components permanently and rigidly.

According to another aspect of the invetnion there is provided an elongate hollow body in the form of a cylinder, constituted by the assembly and joining on site of a series of modules formed of previously prepared longitudinal segmental components each corresponding to a part of the curved cross section of the body, said components bearing on one another along longitudinal joints in which the inner surfaces of adjoining components are flush and said modules being connected by transverse joints, and wherein each module cctnprises, in curved cross section, at least two components, respectively a lower component with a flattened base and another component, at least one structural characteristic selected from the curvature Aandthe thickness of laterally adjacent said ccitponents forming the curved cross section of the module being different, said longitudinal and transverse joints initially permitting limited relative displacements between the adjoining component, said canponents being permanently and rigidly assembled after stabilizing the surrounding ground and the oanploted-hollow body. 203069 O Kj Preferably, the shape of the longitudinal components is determined so that at least some of the longitudinal joints between adjacent components are located proximate to "stress nodes", i.e. points where the absolute value of transverse stresses on the passes through a minimum.

In most cases the joints of structures, according to the invention, are not alternately arranged. On the contrary,the longitudinal joints are continuations of one another to either side of each transverse joint.

A first advantage of the method according to the invention over the current technique is ease of transportation. Assuming that the maximum permissible dimension is 2.5 m, the current techique permits the transportation of one section having an outer diameter at most 2.5 m. If the components of the invention each correspond to a quarter of the ultimate conduit, the latter may have a diameter of about 3.5 m, or twice the cross-sectional area, and if the components each correspond to one-sixth of the ultimate conduit, the latter may have a diameter of about 4.4 m or triple the cross^-sectional area. Further, for a height of t 2.5 m there is available within the same volume space for a considerable number of unitary components stacked on one another whereby the transporting vehicle may carry its maximum useful load. On the other hand the total length S'* £ N *■ v \ \ 2 03 0 of the junctions to be effected by welding or otherwise is obviously increased. It should be observed that they are normally straight joints which are much easier to produce or carry out than circular joints and the number of joints may, on the contrary, be reduced owing to the 5 greater unitary length of the components which is permitted ^ by the reduced unitary weight.

Another advantage of the invention results from the noncircular contour of the structure, the drawbacks of conduits of circular contour having been given above. ■""-s 10 Furthermore, owing to the cross section being / flattened at the base, a considerable improvement of the distribution of the stresses produced in the subjacent ground, and the movements thereof may be greatly diminished. Another advantage of such cross-sectional shapes or pro-15 files is a lesser height for a given cross-sectional flow area, thereby reducing the excavation costs (digging, shielding and holding back subterranean water, etc.). On the other hand, when the consistency of the bearing ground so •'6v>". requires (aquifers in particular) ballast may be incorpo-20 rated on the conduit by means of masses of metal or concrete which are suitably bolted under bottom wall of the ^ conduit. The weight of the ballast is, of course, calcu lated as a function of the actual properties of the particular site and each of the ballast elements may also 25 be prefabricated. The conduit may also be anchored to the ground by the same bolting procedure which is made easier from within owing to the flattened shape of the bottom wall.

Further, the previous calculation of the stresses o 2 030 to which the conduit components are subjected and the use of the results of the calculations to determine the thickness of each component, the variation of the thickness of the transverse section from one point to another, the constituent material of the component and the location of the longitudinal joints, offer important advantages: Frequently the upper part of a conduit only has a protective function and is subjected to limited stress. On the other hand the weight of the fluid carried when it is water or another free flowing liquid, obviously bears more on the lower part than at the top of the conduit. Further, the fluidthightness at the assembly joints permits the conduit to withstand internal pressure and for this reason used for carrying pressurized fluid. It will also be noted that since the ultimate configuration of the conduit is uniform and effectively integral, it will not be necessary to provide abutments for changes in direction wbich^are sources of longitudinal thrust. The possibility of adapting the thickness and the constituent material of the component enables large savings to be realized on the production costs and transportation.

As indicated above, the various components may be of different thicknesses depending on the result of the stress calculations. They may be of different materials on condition, however, that, whenever appropriate, necessary precautions are taken to avoid corrosion caused by electrochemical couples.

Among the materials preferred owing to their relatively low• cost and their availability and ability to be assembled by. 203069 welding or other methods there may be cited ductile cast irons, but other materials may be envisaged alone or in combination, such as steel, aluminum alloys, other metals, fiber-reinforced or non fiber-reinforced plastics, pre-5 stressed or non prestressed, reinforced or non reinforced concrete. In the latter two cases it is obvious that the welds mentioned above are to be replaced with suitable connections.

In case of conduit components cast in a single 10 piece or by continuous profiling, notably, by extrusion, of materials such as ductile cast iron, steel, reinforced concrete, reszns, etc., a mold or die is used having a transverse section shaped to reproduce, by acting on the inner surface of the conduit component the aforesaid 15 variations of optimum profile and also the transverse variation of the thickness.

The changes of direction are obtained by curved or angled prefabricated components which are specially calculated and adapted to the requisite geometry. 20 The fabrication of the conduit according to the invention, i.e., of (part-cylindrical) components corresponding to only a part of the contour or cross section but which, by compensation, may be of great length, poses specific problems at the time of assembly. The problems 25 have been solved by the following assembly procedure which is therefore closely linked to the main feature of the invention. According to this procedure the components are initialy assembled by connecting them both longitudinally and transversely together by means permitting limited 203069 relative displacement of adjacent components and a flexible sealing member is inserted therebetween, and then rigid assembly of the components is effected after the surrounding ground and the entire conduit have been stabilized. Preferably, the initial assembly of the components to one another is effected by means of bolts traversing an corresponding enlarged aperture in at least one of the components.

Nevertheless other modes of assembling the components may be found to be more advantageous, in particular in joints where high stresses require large wall thicknesses. In such cases one or more of the following methods is preferred.

To effect the longitudinal junction and optionally the transverse junction of conduit components, recessed or projections are provided in corresponding edge zones of adjacent components and in form and/or force mating relation for providing the necessary transverse and longitudinal joints* To provide longitudinal joints, a rib is formed on each one of the edges of two components to be joined and clamping means are clamped on the ribs at spaces locations • The clamping means are rigid or relisient U-shaped members; The clamping means are fixed by rigid or resilient shims force-fitted between the inner surface of the clamping means and the flank of the corresponding rib- or by resilient deformation of the actual clamps? The gaskets or sealing members having a section 203069 shaped to correspond with the edges of the transverse and longitudinal joints, are interposed between the edges and their fluidtight sealing action is ensured by means of the clamps or by collars, hoops, prestressing cables or other means; In case the components are made of weldable or bondable materials the longitudinal and transverse joints are effected by additional amounts of corresponding welding or bonding material.

According to an interesting procedure, for faci-litatingthe installation and stabilization of the conduit, stabilizing members of triangular longitudinal section are provided on the side of the lower surface of the conduit. These stabilizing members have a planar horizontal side which is approximately at the level of the bottom of the conduit, an approximately vertical or inclined planar side, and a side which mates with that of the conduit. The stabilizing members are preferably discrete and at spaced locations along the conduit for preventing the lower component from swinging about its longitudinal axis after installation.

The stabilizing members may be secured by bolting, welding or other means on the corresponding structural components of the conduit. In case the-conduit is cast (e.g. in concrete) they may also be integrally formed therewith.

Other than their interest for stabilizing the entire conduit the stabilizing members are advantageous in case the conduit is formed of components of which some bottom -1-.

* O 2 03 D 6 9 and others the sidewalls having a generally vertical orientation. By fixing the stabilizing members beforehand on the sidewall components or forming them in one piece with the sidewall components the latter are able to remain 5 upright, bearing on the ground which facilitates the formation of their junction with the bottom wall components which were brought into position first. Then the upper wall components may be installed by bringing them to bear on the sidewall components.

In case the cross-sectional area of a hollow struc ture is relatively small e.g. a~conduit of about 1 to • 2 4 m , the entire contour may be defined by only two components, one corresponding to the lower part and the sides of the conduit and the other forms a cover. Such 15 components have at least a part which may be made of concrete or other cast or molded material.

According to another method of producing useful joints in case the components are made of concrete or other cast or molded material, there are provided on the 20 edges of the longitudinal components angle members of weldable or bondable material on which is fixed after positioning and preferably after stabilization flat sealing members of a material compatible with that of the angle members.

In certain cases, in particular when transporting or storing dangerous fluids, or for constructing bomb shelters, perfect sealing is required even in case of movements of the ground or a nearby explosion, and if the components are made of concrete or material which may crack or lose its fluidtightness in another manner, a 1. 20306 fluidtight lining or covering is advantageously provided which may or may not be fixed to the components of the structure.

In some cases the lining may form a part of permanent shuttering for the components of the structure. If the lining is made of metallic or non-metallic/or other weldable or bondable material flat members of the type indicated above may be welded or bonded to the joints of this lining, or the parts of the lining between the flat members may be welded or bonded directly thereto at the level of the joints.

If the structure, conduit or shelter, is formed of concrete components, the crush resistance is furnished by the concrete components and the inner lining of metallic or non-metallic sheet or of plastics material, welded bonded or coated provides absolute fluidtightness to radioactive or other contaminations or infiltrations, even if the movements due to the ground or to an explosion have deformed the structure.

The following examples are essentially relative to conduits of large cross-sectional area, but it will be readily understood that it is equally applicable to silos, shelters or other similar structures.

In case of a prefabricated bomb shelter longitudinal wall components are positioned which may likewise be for large cross-sectional conduits and the shelter is closed at its ends by 'planar or convex transverse walls.. Preferably, the shelter has a substantially flat bottom and the base and side components aare equipped with side 2030 stabilizing members integrated during fabrication or added subsequently so as to prevent the shelter from swinging about its longitudinal axis.

Advantageously an inner fluidtight lining is provided particularly if the shelter is built of concrete.

The shelter may be installed very fast, because it is made of separate components which may be easily transported for assembly at the desired site. It may be installed in an excavation which is then filled in or in certain circumstances it may simply be placed on the ground. It will be noted that the flattened dwelling configuration provides enhanced blast resistance compared with masonry shelters of cylindrical or parallelepipedic shape.

The invention will now be described in greater detail with the help of non-limiting embodiments illustrated in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figs. 1 to 3 are schematical cross-sectional views of conduits according to the invention? Fig. 4 is a fragmentary sectional view illustrating a mode of assembly? Fig. 5 is a shematic perspective view of a conduit having its various sections formed of longitudinal components with the joints represented? Fig. 6 illustrates an embodiment of a conduit component having a gradual reduction of radial thickness toward the center? Fig. 7 illustrates an embodiment of a conduit 203 component having a gradual increase of transverse thickness from left to right; Fig. 8 shows a cross-sectional view of a longitudinal joint with ribs and clamping means; Fig. 9 shows an embodiment of interfitting edges between two conduit components for forming a longitudinal or transverse joint; Fig. 10 illustrates an embodiment of a lap joint between the edges of components for forming a longitudinal or transvers joint; Fig. 11 illustrates yet another configuration of edges of components for forming a longitudinal or transverse joint; Fig. 12 illustrates an embodiment of an interfitting transverse joint the fluidtightness of which is ensured by an annular sealing member or gazket of special profile which is compressed by a suitable hoop; Fig. 13 is a cross-sectional view of conduit of Fig. 12, showing the hooping of the sealing member or gasket; Fig. 14 shows a joint for componentsmade of reinforced concrete; Fig. 15 shows a diagram illustrating the results of stress calculations; Fig. 16 is a cross-sectional view through part of a hollow structure of reinforced concrete corresponding to the illustrated results of stress calculations of Fig. 15 ; Fig. 17 illustrates another embodiment specially adapted to small section conduits; 2 03 0 69 Fig. 18 illustrates a mode of providing the fluid- thightness for a joint; Fig. 19 illustrates tightening a joint; and Fig. 20 illustrates another mode of providing sealing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Fig. 1 shows, in solid line, the cross section of a conduit 1 produced in accordance with the invention and by comparison in dashed line the cross section of a conduit 2 having a circular cross section and the same interior cross-sectional area. The conduit according to of the invention comprises five components/the same length assembled together.

Two base components 3 are substantially flat; two side components 4 are of variable curvature greater at the bottom than the top; the conduit profile or cross- section is completed by an accurate upper component 5.

The illustrated example corresponds by way of example to 2 an interior cross-sectional area of 10 m . The overall height H is 2.40 m and the width L is 5.00 m, compared with the diameter D of the corresponding circular conduit which is 3.57 m. The excavation necessary for the conduit that according to the invention is wider at the base than/ of the circular cross-sectional conduit but it is not as deep; all in the volume excavated for the conduit of the invention may be less, and the work may be easier.

Fig.2 shows another embodiment of the conduit according to the invention in which the base components 3a are slightly cambered and there are two upper components 5a instead of one. 203069' Fig. 3 shows yet another embodiment which has the peculiarity of a central trough or gutter 6 along the bottom wall component 3b. The trough or gutter 3b is provided in the middle of component 3b and is slightly flared so that the components 3b are identical and stackable for transport, but other arrangements are possible. According to a conventional technique the provision of such a trough or gutter poses a nearly insoluble problem.

Fig. 4 illustrates a mode of joining two components 4,5 arranged like components 4a and 5a in Fig. 2.

In a first step the component 4 is provided with a connecting plate 7 fixed by a weld 8 which may be done at the factory or at the site. Plate 7 has enlarged apertures 9 which, during assembly, come into register with the enlarged apertures 10 in component 5. On assembly a flexible sealing member or gasket 11 of elastomer or the like, is interposed between component 5 and plate 7 and then securement follows by means of a bolt 12 and nut 13.

When the series of components corresponding to the following section of the conduit is assembled, slight relative movements may occur between components 4 and 5, for example under the action of variations of the level of the excavation. Such slight movements may also be the consequence of consolidation of the subjacent ground. All these movements are made possible by the enlarged configuration of apertures 9 and 10. When these movements have ceased the final joining of the components o 203069 may be effected by a weld 14. The bolt 12 and nut 13 may thereafter be removed, and apertures 9 and 10 or only one of them may be closed off with a weld.

Fig. 5 illustrates in schematic perspective view 5 a conduit made by the method according to the invention. The conduit comprises longitudinal components such as Al, Bl, CI etc. for the first section, A'l, B'l, C'l, etc»for the second section and so on. These components -? .v • are connected to one another by longitudinal joints JL1, 10 JL2, JL3, JL4, etc. and transverse joints JT1, JT2, JT3, JT4, etc.

The method according to the invention comprises a first step of calculating in a known way, the optimum cross-sectional profile of the conduit as a function of 15 known parameters concerning the installation site, the inherent properties of the conduit per se and its conditions of use. In the calculation the forces acting on the conduit are taken into account, including : - the weight of the conduit alone, - the weight of fluid flowing through the conduit, - the pressure established in the conduit, - the possible overpressures resulting of the use • , of hydraulic apparatuses e.g. valves, - the hydrostatic pressure of the subterranean 25 water in which the conduit may possibly be located, - the load of fill covering the conduit, - fixed overload which may possibly be present on the fill, / # 203069 - moving overload which may be caused by the fill, - temperature and hygrometric variations, - reaction bearing forces, etc.

As indicated in the preamble of the description it is interesting to obtain a profile in which the lower part 5 is rather flat and the upper part corresponds to a curve resulting of the optimization of the calculus of the stresses.

The second step comprises dividind the resulting optimum cross-sectional profile into adjacent sections 10 each corresponding to a longitudinal component, such as Al, Bl, etc., together providing a substantially continuous interior surface, designated by S in Fig. 5.

The third step comprises giving the transverse section of at least some of the components a variable 15 thickness for adapting the component to stresses exerted at different points thereon. As illustrated in Figs. 6 and 7 the transverse sections of the conduit components show the thickness of the wall of the component may vary. This feature is extremely important for the fabrication, trans-20 portation and assembly of the component since the amount of material and therefore the weight and the production cost are defined as accurately as possible as a function of the parameters geverning the construction of the ultimate conduit. If the application of the invention to the 25 construction of very long pipelines for carrying petroleum or water, etc. is considered, the effect of a saving in weight on the ultimate profitability of the construction of the pipeline will be readily appreciated. 2 030 69 The conduit components according to the invention may be made of different materials and fabricated by different processes accordingly. Thus it will be possible to envisage the fabrication of elements such as Al, Bl, CI, etc. of metal such as ductile cast iron, nodular cast iron, steel, aluminum alloys, etc. For such materials it is possible to use different processes such as casting piece by piece, continuous casting, extrusion, forging, differential rolling, etc. All these processes permit the production in a uniform manner of the recesses and projecting portions which are to be used subsequently, for assembling the components, in making the longitudinal and transverse joints as will be explained below.

It is also possible to construct the conduit components of other materials, namely, reinforced concrete, fiber recinforced or non-reinforced plastics or resin materials, etc. under these circumstances the elements are made by casting by means of molds or forms which also permit the aforesaid recessed and projecting portions to be obtained.

All the processes of using the above-defined materials for making conduit components according to the invention require the tooling, dies, molds, shuttering, forms, etc., which must take into account the features of the method for producing the conduits according to the invention in the following conditions : - the interior surface of the fabricated conduit component must correspond to the optimum cross- 203069 sectional profile of the conduit, determined by calculation as a function of the known parameters concerning the type of installation, the conditions of use of the conduit and its inherent characteristics. The term "optimum cross-sectional profile" is intended to mean, in the case of external conditions which vary little, an average cross-sectional profile for a given length of the conduit; - each component must have overall dimensions permitting its assembly with other conduit components and the different thicknesses of the components must be calculated to withstand the stresses to which they are to be subjected.

The final sealing is obtained by various means corresponding to each material which is used. It is achieved from the inner space of the conduit after definitive stabilization (settling, compensation of dilatations, compacting etc...) We shall now describe how to assemble the various 20 components to form a conduit, with reference to Figs. 8 to 12 which illustrate several embodiments of longitudinal and transverse joints. Thus, in cross-sectional view in Fig. 8, is illustrated a longitudinal joint provided between conduit components Al and Bl. In this case there is 25 provided to opposite sides of the joints defined by the two surfaces 71 and 72 of components Al, Bl, respectively external longitudinal ribs 73, 74 which extend along the entire length of the corresponding conduit components Al and A2. These ribs may be formed during the casting, extrusion, rolling or molding of the corresponding components or they may be fixed thereto by welding in which case they may be discontinuous. The two ribs permit, as shown in Fig. 5 8, the simple and efficacious securement by a U-shaped clamping member 79 in cooperation with wedges or shims 76, 77 which are force-fitted into position between the clamp and the corresponding ribs by hammering or any other similar procedure.

To absorb any. .forces'.exerted in' a "plane--?— —i-r perpendicular to the cross-sectional profile of the conduit, it is appropriate to provide the lateral edges or surfaces delimiting the conduit components Al, Bl, etc with configurations which permit them to withstand stresses in 15 the best possible way, taking into account the parameters related to the conditions of fabrication and use of the conduit and also the constituent material. Thus, by way of non-limiting examples, there are given in Figs. 8, 9, and 10 several different models of cross-sectional profiles 20 of the lateral edges or surfaces delimiting the conduit components. In Fig. 8, the edges.or surfaces 71 and 72 of delimitation are inclined with respect to the plane perpendicular to the cross-sectional profile of the conduit J components. Such a configuration of the lateral surfaces 25 of the joint are suitable, for example when the static loads exerted on the conduit predominate.

In Fig. 9 the lateral edges or surfaces 79 and 80 of the conduit components Al, 31 have complementarily -« 1 / ; s- o - 14 APR 1986 ^ 203069 rounded shapes so as to absorb the reaction forces exerted in both directions in the plane perpendicular to the cross-sectional profile of the section.

In Fig. 10 is represented step-like lateral edges 5 or surfaces 82 and 83 to form a lap joint or interfit.

In Fig. 11 are illustrated cross-sectional profiles 33 and 34 defining a pocket which may be filled with a sealing material, for example, cast resin.

It is to be noted that these lateral edges or 10 surfaces of the conduit component may be made by any of the foregoing processes. To establish good fluidtightness, in each case there is provided between the lateral edges or surfaces corresponding to the aforesaid longitudinal joints, grout, calking, mastic, cement, liners or other 15 sealing means, namely, of natural or synthetic rubber, as indicated respectively at 78 in Fig. 8, 81 in Fig. 9 and 84 in Fig. 10.

In this respect it should be noted that these joints ensure fluidtightness under pressure.

In Fig. 14 a longitudinal joint is illustrated which is provided between two conduit components Al, Bl made of reinforced concrete. References 20 and 21 designate the respective reinforcements of components Al, Bl.

To provide a connection therebetween, the reinforcements 25 20, 21 are allowed to protrude beyond their components during casting or forming, and once the components are in position at the site of installation of the conduit, the . / 2 03 0 6 9 free ends of the protruding parts of the reinforcements are connected to each other,as shown at 22, then by using suitable formwork or shuttering such as at 26, sealing or anchoring mortar 23 is poured into the existing space 5 to form the sought after longitudinal joint.

In Fig. 14, are shown at 24 and 25 angular and recessed configurations for connecting edges for components Al, Bl. These edge configurations are intended to facilitate the attachment of the sealing mortar 23 and also to perfect 10 the fluidtightness of the joint by forming discontinuities for eleminating local leak passages. References 27 and 28 designate members for holding the formwork or shuttering 26 which are secured into position by means of nuts 29,30.

In Fig. 12 is illustrated an embodiment of a trans-15 verse components such as Al, etc. and A'l etc. of joint between adjacent two sections of the conduit. References 15 and 16 designate transverse edges or surfaces of the transverse joint. In the illustrated embodiment a peripheral joint designated overall by reference 17 is provided com-20 prising a radial bead which is fitted in the annular space between the transverse edges or surfaces 15, 16 and a peripheral ring whose inner surface bears against the outer surfaces of the respective conduit components. The peripheral ring comprises along its outer peripheral surface relief 25 portions or protrusions 19 adapted to be flattened by compression by means of a hoop or collar as shown in Fig. 13 which is a cross-sectional view of the conduit of Fig. 12. In the illustrated embodiment of Fig. 12, given by way of non-limiting example the relief portions or protrusions ...V...... 203069 n 19 may have a dovetail section and dividers in the dovetail recesses so as to define labyrinth type joints. The hoop or collar comprises two parts 18Ar 18B connected together by tensioning means 31, 32 which are adjusted to provide 5 the ultimate tightening.

It should be noted that although all the embodiments of joints between conduit components do not utilize bolts, bolting is certainly not excluded and flange or rim like portions may be formed or fixed on the conduit compo-10 nents and then assembled together by means of nuts and bolts or similar fasteners.

In some applications it is possible, within the purview of the invention, to provide a conduit of composite structure, i.e. some components being formed of a first 15 material such as reinforced concrete in a first part of the conduit, for example the base between the longitudinal joints JL1 and JL4 in Pig. 5, and other components being formed of a second material, for example, a metal or a fiber-reiAforced or non-fiber reinforced plastics material, 20 in the rest of the conduit. Such a composite structure may be recommended for a water supply work in an open ditch, that is, without high loads on the top of the conduit, in a remote area where it is profitable to fabricate the lower part of cast reinforced concrete at the construction site 25 and have the upper part of thin components prefabricated in a factory and transported to the construction site.

Fig. 15 shows, in solid line, the shape of the neutral axis of a conduit section according to the invention 2 G30 6 9 (curve I), in dashed line (curve II) the distribution of the bending moment corresponding to the vertical force exerted by the ground, and in chain-dotted line, (curve III)-the distribution of the bending moment corresponding to the lateral force of the ground. The complete calculation also comprises the determination of a certain number of similar curves, corresponding, for example, to the internal pressure, the weight of the conduit itself, etc. The calculation then comprises the combination of the results each corresponding to a type of stress.

It will be observed that the complete cross-sectional profile or shape of the section comprises four "nodal" zones, located in the lower part of the conduit and in the upper part of the conduit.

Fig. 16 shows a half cross-sectional view of a conduit formed of four reinforced concrete components.

It is noted that the thickness (h^, h2) in the zones corresponding to the highest stresses in Fig. 15, i.e., at the middle of the base and along the sides is about 50 % greater than the thickness h3 at the top. The joints JL1, JL2 between components have been placed in the "nodal" zones. In this figure the reference fl designates the reinforcement members embedded in the concrete of the components fabricated beforehand and reference f2 designates the anchoring members which arebent over one another before being embedded in the concrete during the construction of the structure.

Fig. 17 shows an embodiment adapted for a relative 2 small cross-sectional area conduit: about 1.5 to 4 m .

For the sake of simplification, the section of the conduit 2 030 6 9 is divided into two components which may be transported separately without particular difficulties by reason of their small dimensions. The lower component 4 0 is cast in concrete and comprises a flat-bottom base and the sides. 5 It will be observed in addition that the lower component 40 comprises stabilizing members 41 which are integrally formed therewith and facilitate installation in a flat-bottom ditch. The stabilizing members 41 are of generally tricingular cross-section with their lower sides horizontal. 10 For the sake of lightening the weight of the structure the stabilizing members do not extend along the entire length of the component 40. The upper component 42 of the conduit is of simpler shape, being of inverted gutter shape with a very small curvature. The upper component 43 15 may be cast, molded or extruded. In case the lower component 40 is to be extruded it is plain that the stabilizing members 41 will have to be fixed subsequently, but before installing the conduit, by bolting, welding or any other suitable means.

In Fig. 16 is illustrated a stabilizing member 41.

This figure reveals another advantage of the stabilizing member in the case of a structure having a section formed of more than two components. Indeed, it will be noted that the side component A2 provided with the outer stabilizing 25 member 41 is self-supporting in its ultimate position.

Provisional support during the formation of the joint JL2 with the base component A3 is therefore unnecessary.

It is also noted in the case of a structure bearing on the ground, the stabilizing member increases the resistance to lateral forces tending to overturn the structure, . _r 203 which is advantageous in the case of a bomb or other type of shelter which may be supported on the ground and exposed to the effects of a blast.

Fig. 18 shows a method of making fluidtight joints 5 in the case the components are not weldable nor bondable, z being made of concrete for example.

Each component Al, A2 has along its edges angle members 43 of weldable or bondable material, e.g., ferrous metal, which are secured in place during casting if the 10 component is so fabricated. The flat connecting members 44 of ferrous metal or other material weldable or bondable= on the angle members 42 are welded or bonded to the latter, possibly after being stabilized on the ground.

Fig. 19 shows another assembly method for structures 15 according to the invention.

One of the components Al comprises a threaded bore 45 which may be provided in a bush or insert 46. The threaded bore 45 is dereeted approximately perpendicular to the plane of the joint. The other component A2 has a shoulder 47 with a hole 48 in which a threaded fastener 49 is inserted and threaded into the bore 45, there being clearance between the shank of the fastener 49 and the hole 48.

Fig. 20 shows another embodiment for making the joint 25 fluidtight in which the concrete components Al, A2 are provided along their inner surfaces with a fluidtight liner or covering 50 of sheet metal defining permanent shuttering. A flat interior member 44 is then welded directly to the liner 50. An angle member similar to those shown in Fig. 18 may be provided on the other side of i • ; . v , r- -1- — — ._ .

O 203069 components Al, A2.

It is to be noted that certain of the above mentioned assembling dispositions are used for the installation of the conduit, and do not sustainalone essentially the hydrostatic pressure in the case of a pressurized conduit, 5 since in this case the hydrostatic pressur is partly compensated by the thrust of the packing.

For a better solidarization of the components of a conduit, shelter etc., and to make easier the obtention of the joints, one may provide, other than encirling 10 cables, prestress cables or bars which connect therebetween longitudinal components which are lengthwise adjacent.

Each of those cables or bars may connect at least two consecutive components. For instance a component may be connected to the following by a set of cables or bars, 15 and to the preceding by another set of cables or bars, thereby the prestress may by operated pregressively during Each the process of installation./prestress cable or bar may also connect three consecutive components or more.

Claims (1)

1. WHAT I CLAIM IS: 203069 1 .7 •vL*;3=;$r o;1. A method for producing an elongate hollow body in the form of a cylinder bearing on the ground along a flattened base by assembling and joining on site a series of modules formed of previously prepared longitudinal segmental components each corresponding to a part of the cross section of the hollow body, said components bearing one another along longitudinal joints, in which the inner surfaces of the adjoining components are flush said method comprising preparing at least two types of components, in cross section, respectively a lower component with a flattened base and an upper component, at least one structural characteristic of said laterally adjacent components, selected from the curvature, the thickness and the material, being different and then forming a module by first positioning the lower component and then the upper component and assembling said components together so as to permit limited relative displacement therebetween and assembling adjacent modules one to the other along transverse joints so as to permit limited relative displacement therebetween and then after stabilizing the surrounding ground and the oomplotod hollow body, assembling the adjacent components permanently and rigidly.;2. A method according to claim 1, in which said longitudinal components are devoid of corrugations.;3. A method according to any one of claims 1 or 2, wherein said components are molded in one piece or continuously formed by extrusion, the material being selected from ductile cast iron, steel, reinforced concrete, fiber reinforced or non-reinforced plastics or resin material.;4. A method according to any one of the preceding claims including locating said components such that at least some longitudinal joints between laterally adjacent components are situated where the absolute value of stresses transverse to the hollow body wall will be substantially nil.;- 30;• 203069;1 5. A method according to any one of the preceding;2 claims, wherein said components are assembled and joined;3 to other components adjacent in the longitudinal sense;>;4 by transverse joints and wherein longitudinal joints;5 between adjacent components are collinear on each side;6 of each transverse joint.;1 6. A method according to any one of the preceding;2 claims, wherein the components differ from one another;3 in respect of the material of which they are made, said;4 materials being selected so as to avoid corrosion caused;5 by electrochemical couples.;1 7. A method according to claim 6, wherein compo-;2 nents of the lower part of the hollow body are made of ^ 3 . concrete and components of the upper part are made of;4 metal.;1 8. A method according to preceding claims wherein the;2 initial assembly of adjacent components includes extending;3 bolts through an enlarged aperture in at least one of;4 the adjacent components.;1 9. A method according to any one of the preceding;2 claims, including effecting . joints between adjacent;3 components by interengaging recesses and projections of;4 complementary shapes in corresponding edge zones of;5 adjacent components.;1 10. A method as claimed in any one of the preceding;2 claims, including effecting longitudinal joints and transverse;3 joints between adjacent components by interengaging;4 recesses and projections of complementary shapes in;5 corresponding edge zones of adjacent components so shaped;6 as to absorb forces exerted ■;7 in a plane perpendicular to the cross-sectional profile of;8 the components.;1 11. A method according to any one of claimsl to 8;2 wherein longitudinal joints between laterally adjacent;3 components include a rib provided on each of the corres-;4 ponding edges of adjacent components, and assembling;5 clamping means on the ribs of said adjacent comjo^;6 at spaced locations.;31;2;1;2;3;4;1;2;3;1;2;3;4;5;6;1;2;3;4;5;1;2;3;1;2;3;4;5;1;2;1;2;3;1;2;4-',;5;203069;12. A method according to claim 11, wherein said clamping means are U-shaped members.;13. A method according to claim 12, including force-fitting resilient shims between the inner surfaces of the clamping means and the adjacent surfaces of the corresponding ribs.;.14- A method according to claim 12 , including securing said clamping means to the associated ribs by resiliently deforming the U-shaped members.;15. A method according to any one of the preceding claims wherein the hollow body can carry pressurized fluid, and assembling and clamping sealing members having a cross-section shaped to correspond with the cooperating edges of adjacent components between said cooperating edges to define sealed joints.;16. A method according to any one of claims 1-14, wherein the hollow body can carry pressurized fluid, said components being formed of weldable or bondable materials and said joints being defined by additional amounts of the corresponding welding or bonding material.;17. A method according to any one of the preceding claims, including after assembling said components stressing the hollow body longitudinally and/or transversally.;18. A method according to claim 1, including providing stabilizing members'of substantially triangular transverse section on sides of a lower component of the hollow body for facilitating installation and stabilization of the body. 1;19. A method according to claim 1, including providing a fluidtight lining on the components.;20. A method according to claim 19, wherein said fluidtight lining comprises permanent shuttering for the components of the hollow body.;21. A method according to claim 20, wherein said lining is made of a weldable or bondable material and including welding or bonding flat members of material compatible with that of the lining to edge parts of the lining to effect fluidtightness at joints between adjacent;32;•* vw-:»r. ~ ■ 4-; x rrari <i~ ■■• n a03069 6 components.. 1 22. A method according to claim 20 ( wherein 2 said lining is made of a weldable or bondable material, and 3 including welding or bonding parts of said lining directly 4 to each other at joints between adjacent components. 1 23. A method according to claim 1, wherein a 2 threaded bore is provided in one of the adjacent components 3 defining a joint and extends approximately perpendicular ^ 4 to the plane of the joint, and inserting a threaded 5 fastener in a hole in the other of the adjacent body 6 components and threadedly engaging it with the threaded 7 bore for assembling said adjacent components together. 1 24. A method according to claim 1, including fixing ballast 2 or anchoring means to a lower component defining -a- flattened 3 base of the hollow body. 1 25. A method according to claim 24 including 2 fixing said ballast or anchoring means to said lower 3 part by bolting from inside the hollow body. 1 26. A method according to claim 1, wherein said 2 hollow body is a conduit and including assembling modified 3 curved or angled prefabricated components therewith to 4 change directions of the conduit. 1 27. A method according to claim 18 wherein said 2 stabilizing members have a plane horizontal side substantially 3 level with the bottom of the hollow body and a plane 4 substantially vertical or inclined side and a complementary 5 curved side mating with an outer surface of the lower 6 component of the'hollow body. w' 1 28. A method according to claim 27, including 2 spacing said stabilizing members along the hollow body. •3 29. A method according to claim 27 including 4 securing said stabilizing members to a said lower component. 5 30. A method according to claim 2 7 wherein said 6 stabilizing members are molded or cast in one piece with 7 lower components of the hollow body. 1 31. A method according to claim 1, including 2 fixing stabilizing members of substantially triangular transverse section to sidewall components of the conduit 4 for maintaining said sidewall components in upright 4 APR 1936 33 position on the ground. 203069 32. A method according to claim 1 further comprising assembling at least two said longitudinal components in a relationship where they are lengthwise adjacent including connecting said at least two longitudinally adjacent components by tensioning prestressing cables or bars. 33. A method according to claim 32 including joining at least one of said components to a longitudinally following component by a set of prestressing cables or bars, and where the at least one of said components is connected to a longitudinally preceding component by another set of prestressing cables or bars. 34. An elongate hollow body in the form of a cylinder, constituted by the assembly and joining on site of a series of modules formed of previously prepared longitudinal segmental components each corresponding to a part of the curved cross section of the body, said components bearing on one another along longitudinal joints in which the inner surfaces of adjoining components are flush and said modules being connected by transverse joints, and wherein each module comprises, in curved cross section, at least two components, ■^respectively a lower component with a flattened base and inother component, at least one structural characteristic I lUft r^od&ricxl elected from the curvature and the thickness of laterally adjacent said components forming the curved cross section of the module being different, said longitudinal and transverse joints initially permitting limited relative displacements between the adjoining component, said components being permanently and rigidly assembled after stabilizing the surrounding ground and the completed hollow body. 35. A hollow body according to claim 34 characterized in that said lower part is constituted of three components, respectively a flat base component and two sidewall components. 36. A hollow body according to claim 35, characterized in that said sidewall components are provided with stabilizing members of substantially triangular transverse section, for maintaining said sidewall components in upright position on the ground without auxiliary supports, - 34 - —I • 203069 o 6 7 '8 9 10 1 2 1 2 3 1 2 3 1 • 2 3 4 5 6 1 2 3 4 5 1 2 3 4 1 2 3 1 2 3 said stabilizing members having a plane horizontal side substantially level with the bottom of the body and a plane substantially vertical or inclined side and a complementary curved side mating with an outer surface of the sidewall components of the hollow body. 37. A hollow body according to claim 36 wherein said stabilizing members are spaced along the hollow body. 38. A hollow body according to claim 37, wherein said stabilizing members are secured to a said sidewall component. 39. A hollow body according to claim 38, wherein said stabilizing members are molded or cast in one piece with sidewall components of the hollow body. 40. A hollow body according to one of claims 34 to 39 wherein said components are molded in one piece or continuously formed by extrusion, the material being selected from ductile cast iron, steel, reinforced concrete, fiber reinforced or non-reinforced plastics or resin material. 41. A hollow body according to claim 34 wherein said hollow body has a composite structure, at least one of said components being made of a first material and at least another of said components being made of a second material. 42. A hollow body according to claim 41, characterized in that the at least one lower component of the hollow body is made of concrete and the at least one upper component of the hollow body is made of metal. 43. A method for producing hollow bodies substantially as herein described with reference to any one of the embodiments shown in the accompanying drawings. 44. A hollow body substantially as herein described with reference to any one of the embodiments shown in the accompanying drawings. i4APRW86 BAIEWIN, scar &[ CAREY 35