US3111811A - Method for the construction of a tunnel or tunnel-part and a tunnel or tunnel-part obtained by pursuing said method - Google Patents

Description

3,1 1 1,81 1 UNNEL-PART INED NOV- 26, 1963 A. EGGINK ETAL METHOD EOR THE CONSTRUCTION OE A TUNNEL OR T ANO A TUNNEL OR TUNNEL-PART OBTA BY PURSUING SAID METHOD 2 Sheets-Sheet l Filed Dec. 9, 1957 FIG.1

ANTON EGGINK HENRICUS CORNELIS HENIINK BIZE STAMHUIS IN VENTORS Nov. 26, 1963 A. EGGINK ETAL 3,111,811

METHoD EUR THE CONSTRUCTION oF A TUNNEL oa TUNNEL-PART AND A TUNNEL 0R TUNNEL-PART OBTAINED By PUEsUING sAID METHOD 2 Sheets-Sheet 2 Filed Deo. 9, 1957 INVENTOR` ANTON EGGI'NK HENRICUS ,CORNELIS WENTINK BY EIZE STAMHUIS Eands Fiied Dec. 9, 1957, Ser. No. 701,562 Claims priority, application Netherands Een. i5, i955 i Claims. (Cl. 51-42) The invention relates to a method for the construction of a tunnel or tunnel-part to be built under water or under the ground-water level and to a tunnel or tunnel-part obtained by pursuing this method. rJhe invention can be used if the work is performed according to the open trench method or according to the sinking method.

As a rule the invention will serve for the construction of trarlic tunnels, either for motor-car, railway, tramway, bicycle or pedestrian traflic, or for a combination of this kind of trailic. Nevertheless it will also be possible to construct other kinds of tunnels in parts or over their whole length by means of the method of the invention.

The construction of tunnels or tunnel-parts in various forms of the cross-prole (circular, rectangular, etc.) in a trench which has been drained temporarily or by means of the sinking method is well-known. The inner tunnel-space, necessary for traiiic, ventilation, ducts, etc. is enclosed by a wall which should be strong enough to receive the :loads present, should have suiiicient weight against buoying up and should be water-tight, Any tunnel-construction should meet these three demands.

With the known embodiments all the loads are received by one single wall of reinforced concrete, which either possesses sutlicient weight against buoying up or is surrounded by an additional weight of ballast concrete. The water-tightness is obtained by a separate water-tight coating or layer. If the work is performed according to the sinking method it is inevitable with the existing embodiments that the water-tight iaycr consists entirely or for a considerable part of an expensive, welded steel mantle. With the open trench method the water-tight coating consists of a cheaper yielding layer, for which generally asphalt-immersed fabric is used. Furthermore the tunnels according to the known constructions should be built almost entirely in the open air, so that the work depends f on the 'weather conditions and the further conditions at the site. Since these conditions are not equally important for each building phase, the proceeding of the whole work is determined by the phase which is iniiuenced most in a detrimental sense by the said conditions. As a rule this is the production of the water-tight layer, upon which of course high demands should be made. Finally the water-tight layer should be protected against chemical and mechanical iniluences such as rustingwith the use of a steel mantle-and damaging by dragging ships anchors. This protection renders in many cases special provisions necessary, as a result of which the costs of the water-tight layer, which are often already high, are even increased.

With the invention quite a new style is adapted, consisting in the iirst place in that the wall is composed of two parts, which make each a suitable contribution with respect to the requirements as to strength, weight and water-tightness and furthermore such, that the advantages of prefabricated building are obtained and the drawbacks inherent in the existent constructions are obviated.

The most important component which lies behind the State tet calculation of strength of the wall is the soil-stress. From soil-mechanics it is known that this soil-stress (ag) is composed of the grain-stress (ak) and the water-stress (aw) according to the law ag=ak+aw.

This law is applied to the present problem, to such an extent that the water-tight layer is supported by a construction which mainly resists the water-stress, while the other loads are received by a second construction. The wall is therefore composed of two parts, of which one part, the inner wall, is adapted to resist entirely or substantially entirely the water-stress, the other loads being borne by an outer wall. The inner wall is constructed of water-tight material or is provided with a water-tight coating. The resultant of the water-stress on the inner wall, being the buoying force, is here larger than the weight proper of this wall and the construction parts to be mounted inside. The difference between the two forces is the reaction force which is received by the outer wall in addition to the grain stress and the other loads. To that end the outer casing does not only possess sufiicient strength, but also sutlicient weight. Since the inner wall need not meet the demand of sufficient weight against buoying up but only the demands of water-tightness and strength against only part of the loads, a light construction is obtained and it becomes possible to prefabricate this wall, ir necessary together with the watertight layer, in elements or sections of transportable weight and satisfactory length in a factory or work-shop. Consequently it will be possible to construct these sections with more care, if necessary more rapidly and possibly more cheaply than at the site of the tunnel or the tunnelpart in a trench or, if the work is performed according to the sinking method, in a dock or on a slipway. In this way the advantage is gained that a large part of the building need no longer take place in the open air and that the provision of a possibly required water-tight layer does no longer determine the procedure of the whole lwork. The sections of the inner wall are interconnected in a water-tight manner.

In order to cause the water-stress on the inner wall to be even and complete from the onset, a porous layer is applied to the outside of this wail or on the water-tight layer-if present-or a free space is kept between the inner and outer wall, which layer or space is connected with the water surrounding the tunnel.

If the material, of which the inner -wall is constructed, is not water-tight in itself, it is surrounded by a watertight layer of yielding material, which is ultimately enveloped by the outer wall and, as a result, is protected thereby in such a way that the work can also be performed according to the sinking method.

The fact that the invention offers considerable advantage as compared with the existing sunk tunnels is a result of the particular construction shape, which is such, that the heavy outer wall has strength-properties, by which it can receive the forces during the transport and the sinking of the tunnel-parts and offers at the same time suiiicient protection against damaging of the watertight layer by dragging ships anchors. Another advantage is thus that a separate protection of the yielding layer can also be left oit if the work is done according to the open trench construction.

Y The inner wall may consist of different material or material with a composition other than 'the composition of the outer wall. Thus it will lbe possible 'for instance to choose for :the inner wail `a construction of prestressed concrete or of reinorced concrete, for the outer wai-l ya reinforced concrete construction or a concrete yconstruction provided with a `light reinforce-ment. in order to reduce the num -ber yand thus :the costs of the connections or joints between the sections of the inner wall as much as possible the Patienten uw. as, tsss` einen length of the separate sections should be as great as possible. rf'his implies that the weight per unit of length be as small as possible, since the total weight of one section is limited by the admissible load of the means of transport. This is attained by ltaking the following measures, if necessary combined:

(a) The sections of the inner casing are constructed of prestressed concrete and obtain the shape of thin shells, which are borne by reinforcing rings at their ends and/ or elsewhere divided over the length.

(b) The circumference of the shells mentioned under a has the shape of -a closed differentiable curve. For it is known from the mechanics of shells that such a shaped tube profile is kept in equilibrium by membrane stresses, provided that rafters are present, to which the shell transmits the load by means of shearing stresses. The shell is then only subjected to normal stresses and shearing stresses, while the reinforcing rings should moreover receive bending stresses as a result of moments. Edge disturbances occur in the neighbourhood of the reinforcing rings, as a result of which the shell is no longer entirely :bending-free on said spot over a ycertain Zone. Since the reinforcing rings are enclosed on all sides in the outer casing they have a high degree of stability against bending when they have this shape.

(c) The reinforcing rings are dimensioned corresponding with the load conditions during the building stages and are subsequently connected to the outer wall in such a way that it cooperates in receiving the bending moments, cross-forces and normal forces as a result of the definite loads. ln this way also the reactions of the inner and outer wall are transmitted very favourably. The connection between reinforcing rings and o-uter wall is effected by steel anchors and/ or cams.

`(d) During the building stages the reinforcing rings are reinforced by the provision of temporary spokes or drawbars (principles of the spoke-wheel).

In order to transfer the forces of the reinforcing rings on the outer casing, while the watentightness on the spot is maintained, the yielding water-tight layer around the inner casing near the reinforcing rings is interrupted by a steel coating, which is connected to the yielding layer, while the steel coatings of the end-reinforcing rings of the connecting Amembranes are connected with each other in a water-tight manner.

An embodiment of the invention is hereinafter `described. In the embodiment chosen the cross profile of the inner wall is of an oval shape. It stands to reason that it is also possible to have an embodiment in which the cross prole has in the main a different shape, for instance a circle, rectangle or a rectangle with rounded corners. The oval shape has been chosenalthough as far as is known, this shape has never been appliedsince it offers a more satisfactory solution, as is apparent from the above; at least for 'the solution chosen here for a two-way traflic tunnel for ordinary traffic or for railway traflic.

FIGURE 1 shows a cross-profile of a tunnel or tunnel part for a two-way traic tunnel for ordinary traffic according to the invention; FIGURE 2 a corresponding cross-profile of a tunnel for railway trafiic.

FIGURE 3 shows part of a length proiile of a tunnel or tunnel-part corresponding with FIGURE l or 2, in which the construction parts within the walls have been left out. The prefabricated parts of the inner wall are constructed of prestressed concrete, as shells supported by end-reinforcing rings.

FIGURE 4 shows a detail of a longitudinal section of the `two walls on an enlarged scale.

FIGURE 5 shows .la joint between the reinforcing rings of adjacent intersections.

In the figures reference numeral l represents the inner wall consisting Iof prestressed concrete, 2 the yielding water-tight layer, 3 the outer wall consisting of reinforced concrete.

In FIGURE 1 reference numeral 4 represents the tralhc space, '5 and 6 ducts for the supply yand discharge of air respectively, 7 a duct for cables and lines.

In FIGURE 2 reference numeral d represents the traffic s ace and the ballast bed.

In FIGURE 3 reference numeral 9 represents lthe endreinforcing rings of [the inner casing constructed as a shell and l@ the steel coatings of the said reinforcing rings.

ln FIGURE 4 reference numeral ll represents the porous water-carrying layer or hollow space.

In FIGURE 5 the construction of reinforcing rings 9 are illustrated. The steel protection lo protects the concrete of reinforcing ring 9 and also serves as a convenient fastening point for the anchors which reinforce the connection `with the concrete of outer wall 3. The asphalt i ersed `fabric is fastened on the edge of the steel pro teo on lo by means of strips l2. A water type connection is provided between the two sections by rubber strip i3.

T he two tunnels have been designed for the crossing of an ocean ship canal with a water-depth of 15 m. The dimensions of rthe walls are for both tunnels entirely the same; the inside height of the inner wall is 8.90 m., the inside width is 10.60 m.; the outside height of the outer Wall is 16.80 m., the outside breadth 12.90 m. The FlGURES l and 2 represent -the cross-sections over the deepest point of the tunnels, where the ground-coating is approximately 1.50 m. The waterstress on the inner coating proceeds linearly wit-h the height ybetween the Ilimits 17.3 and 26.5 t./sq. rn.

The weight of the inner `construction parts is evenly distributed over fthe lower part of the inner wall, the trathc loads too. These loads have the effect of a reduced water-stress over this part of the inner wall.

The thickness of the shell amounts to 0.14 m. The .reinforcing rings have been dimensioned by taking the measures mentioned above under c and d. The average weight per metre run of the inner wall amounts to 14.5 tons. In connection with the admissible load of 90 tons of the means of conveyance available the length of the sections has, 'for the time being, been assumed at 6 m. With a larger admissible load the length is enlarged proportionally and, if necessary, the sections are provided with intermediate reinforcing rings.

Since, owing to the Water-stress, there occurs :already a tangential pre-stressing in the shell only a pre-stressing in `an axial direction is applied in this shell, the size of which is determined by the edge disturbances. However, these edge disturbances are reduced considerably since the reinforcing rings are pre-stressed tangentially.

The outer wall is made of reinforced concrete, the thickness amounts to (LSG-1.00 rn., the percentage of reinforcement is low as a result of the favourable shape against `all-sided stress. Forces and moments in axial diection from sag Idifferences are received by the longitudinal reinforcement.

rl`he water-:tight coating consists of asphalt layers which have been reinforced by fabric, said layers having been glued in asphalt, the porous layer being made of heavy felt-paper, the outside of which coating having been covered with a means which prevents cement water from penetrating into the layer during the time the wall is poured.

The members of the inner wall are constructed in a factory or workshop, |for which Ionly a few wall moulds and only a very small team of skilled labourers are required. Also the vvatentight coating and the porous layer are `mounted in the factory.

On the site of the tunnel-trench, dock or slipway, depending on the construction method chosen-the sections which have thus been prefabricated are mounted one behind the other at the correct height and place, the joints are closed, lthe reinforcement of the outer wall is mounted, the casing of this wall is provided and the yconcrete thereof is poured. In this Way it is possible to form tunnelsparts of the desired length. Since the inner wall also serves as inner casing of the outer Wall only one casing is required at the site, viz. the `outer casing of the outer Wall.

If the construction parts present withinthe inner Wall Iare absent the tunnel Will float, the completely nished tunnel sinks, and the position of floating lies in between. Lf the Work is `carried out according to the sinking method the sinking Weight can consequently be controiled by simple auxiliary means-small floaters for example-by previously mounting part of the interior parts.

We claim:

1. A method for the construction of a tunnel, comprising the steps of prefabricating `a plurality of thin-Walled shell-shaped, tubular sections of concrete, having an outer reinforcing ring at each end, `coating all ott the outer surface of said sections except `at said rein-forcing rings with a yielding layer of Waterproof material such as asphalt, joining said sections water-tight end to end and casting `an outer Ilayer of `concrete around said joined sections, said outer layer being only connected to said sections at said reinforcing rings and being `further spaced from said sections by said yielding intermediate layer.

2. A `method for .the construction of a tunnel, comprising the steps of prefabricating la plurality of thin-Walled, shell-shaped tubular sections of concrete, reinforced by outer reinforcing rings, lying in axially spaced planes perpendicular to the axis of the sections, `coating 'all of the outer surface of said sections except at said reinforcing rings with a yielding layer of Waterproof material such as asphalt, joining said sections Water-tight end to end, and `casting an outer layer of concrete around said joined sections, said outer layer being only `connected to said sections -at said reinforcing rings and being yfurther spaced from said sections by said yielding intermediate layer.

3. A tunnel according to :claim 2 wherein said sections have an outer reinforcing ring `at each end thereof, said sections being joined `at said reinforcing rings.

4. A tunnel `comprising a plurali-ty of thin-Walled, shellshaped, tubular sections, said sections being joined end to end Eby Water-tight joining means, each of said sections having at least one outer reinforcing ring, a yielding intermediate i'ayer of waterproof material such `as asphalt on the outer surface of said sections except at said reinforcing rings, and an outer wall of yconcrete surrounding said sections and said reinforcing rings and spaced from said sections by said layer of Waterproof material, said sections being supported within `said outer Wall by said reinforcing rings.

References Cited in the tile of this patent UNITED STATES PATENTS 485,983 Powell Nov. 8, 1892 822,705 Wilson June 5, 1906 1,549,406 De La Mare Aug. 11, 1925 1,741,049 De La Mare Dec. 24, 1929 1,831,322 Porter etal Nov. 10, i931 2,568,010 Kieser Sept. 18, 1951 2,731,800 Collins Jan. 24, 1956 2,808,851 James Oct. 8, 1957 FOREIGN PATENTS 244,664 Germany Mar. 14, 1912 557,225 France Apr. 28, 1923 115,493 Switzerland Iuly 1, 1926 132,082 Austria May 25, 1955 294,289 Australia May 10, 1956 OTHER REFERENCES Engineering News Record, Oct. 17, 192.9, pp. 600 to 696.

Claims (1)

1. A METHOD FOR THE CONSTRUCTION OF A TUNNEL, COMPRISING THE STEPS OF PREFABRICATING A PLURALITY OF THIN-WALLED SHELL-SHAPED, TUBULAR SECTIONS OF CONCRETE, HAVING AN OUTER REINFORCING RING AT EACH END, COATING ALL OF THE OUTER SURFACE OF SAID SECTIONS EXCEPT AT SAID REINFORCING RINGS WITH A YIELDING LAYER OF WATERPROOF MATERIAL SUCH AS ASPHALT, JOINING SAID SECTIONS WATER-TIGHT END TO END AND CASTING AN OUTER LAYER OF CONCRETE AROUND SAID JOINED SECTIONS, SAID OUTER LAYER BEING ONLY CONNECTED TO SAID SECTIONS AT SAID REINFORCING RINGS AND BEING FURTHER SPACED FROM SAID SECTIONS BY SAID YIELDING INTERMEDIATE LAYER.

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