EP1596011A1 - Process and apparatus for producing an immersed tunnel on subsea ground - Google Patents

Abstract

The method involves constructing a submerged tunnel (1) on a submarine ground by utilizing a machine. The machine is advanced in the water on the ground, upon request, along the way planned for the tunnel. The tunnel is maintained watertight along its entire construction. Communication is established between a constructed part of the tunnel and a workspace of the machine for permitting installation of a new section of the tunnel. An independent claim is also included for a device for implementing a submerged tunnel constructing method.

Description

The invention relates to the realization of a submerged tunnel under a body of water.

Many techniques have been proposed to achieve a tunnel under a body of water, usually an expanse of marine water.

Some techniques are related to the case where the tunnel must be done primarily in the underlying terrain at the bottom of the body of water, as illustrated for example by publications DE 50 882, JP 9 316 901, GB 348 204, EP 0 899 422, JP 09-273382, JP 2,024,489, US 1,441,698, US 4,889,448.

In fact, a common solution in this case is to use a tunnel boring machine to drill the ground, evacuate material drilled to the rear of the tunnel boring machine and build the tunnel to progress by successive sections, as for the construction of a tunnel through a mountain range.

A tunnel thus realized under the bottom of the mass of water has the advantage of offering no obstacle to the traffic but against other disadvantages, requires to make access works all the more long as the tunnel is located at a deep level under the bottom of the sea.

The present invention relates to the case where the tunnel must be carried out partially or totally in the water, on underwater or sub-fluvial land, natural or man-made, and in what follows the expression underwater soil will be interpreted as covering all these cases.

The publication DE 33 33 850 describes a technique where the tunnel is realized by successive sections which are prefabricated in a waterproof excavation and pushed gradually into the water up to their location service.

Another common technique is to build in surface (on land or on a ship) tunnel sections rings, to bring them to the installation site, then to fail on the underwater ground in their final position and to to assemble them.

This technique requires having a site likely to host a dock for the realization of sections, or a launching facility of prefabricated sections on land, and generates genes important for maritime traffic, including the fact that the sections usually have a long length of several tens of meters, even up to a hundred meters and more.

An object of the invention is notably to avoid the construction of heavy terrestrial infrastructures (darse or launching facility), to considerably reduce obstacles to navigation, and to reduce costs and construction times.

One aspect of the invention is a method characterized in that the current submerged section is constructed underwater (natural, prepared or artificial, whether result from preliminary backfilling or dredging) means of a machine capable of functioning in immersion and that it is made to move in the water, on the underwater soil, to the request, along the planned path for the tunnel, this machine having a pressure-tight work space under pressure Atmosphere suitable for staff and equipment required for the construction and in-situ laying of the section, in what is kept tight the tunnel as and when its construction, in that one ensures between the part of the already completed tunnel and the machine work space a sufficient communication to allow the construction and laying a new section, and in that we use the tunnel, as it was built, to transport to the request in the room the constituent elements of the sections.

• on construit le tunnel par tronçons courts successifs d'au plus quelques mètres de longueur, de préférence d'une longueur individuelle inférieure à 3 mètres ;
• on utilise la machine pour préparer partiellement ou totalement le sol sous-marin, à l'avancement, en vue de la pose du tunnel, au moyen d'outils intégrés à ladite machine ;
• on prépare le sol en nivelant le sol ou une couche rapportée sur le sol ;
• on réalise par dragage un fond de souille le long du trajet prévu pour la pose, avec s'il y a lieu apport de matériaux d'assise, et on nivelle ce fond ;
• on réalise un traitement de consolidation ou d'amélioration de la capacité portante du sol à l'avancement à l'aide de moyens intégrés à ladite machine ou depuis l'intérieur du tunnel déjà réalisé ;
• on déplace par étape la machine sur le sol sous-marin en avant du dernier tronçon posé pour dégager chaque fois l'espace nécessaire à la mise en place du tronçon suivant et à l'injection de son assise définitive ;
• on fait avancer la machine sur le sol sous-marin par poussée vers l'avant en prenant appui sur la partie de tunnel déjà réalisée ;
• on exerce cette poussée au moyen de vérins ;
• on exerce sur la machine une traction de retenue dirigée vers la partie de tunnel déjà réalisée, en tant que de besoin pour faciliter le guidage de la machine, comprimer les joints d'étanchéité transversaux, et assurer la stabilité temporaire des derniers tronçons posés lorsque la poussée frontale hydrostatique sur la machine est insuffisante ;
• on exerce cette traction au moyen d'un dispositif tracteur relié à la machine par un câble courant dans la partie de tunnel déjà réalisée ;
• on munit la machine d'un compartiment ballastable pour régler la force d'appui de la machine sur le sol et faciliter son guidage dans le plan vertical ;
• on dispose les outils de préparation du sol et/ou de traitement de consolidation ou d'amélioration de la portance de sol dans la chambre ballastable ;
• on utilise la machine pour réaliser également les tronçons d'accès non immergés, partiellement immergés et/ou peu immergés du tunnel.

The method of the invention, in its implementation, may still have one or more of the following advantageous characteristics, combined or not:

• the tunnel is constructed in successive short sections of not more than a few meters in length, preferably of an individual length of less than 3 meters;
• the machine is used to partially or totally prepare the underwater soil, in progress, for the installation of the tunnel, by means of tools integrated in said machine;
• the soil is prepared by leveling the soil or a layer added to the soil;
• a bottom of soil is dredged along the path provided for laying, with the provision of bedding materials, and this bottom is leveled;
• a consolidation or improvement treatment of the bearing capacity of the ground is carried out with the aid of means integrated in said machine or from inside the tunnel already made;
• the machine is moved step by step on the submarine ground in front of the last section laid to free each time the space necessary for the installation of the next section and the injection of its final seat;
• the machine is advanced on the submarine ground by pushing forward by building on the tunnel part already made;
• this thrust is exerted by means of jacks;
• a pulling traction is applied to the machine directed towards the tunnel part already made, as necessary to facilitate the guiding of the machine, to compress the transverse seals, and to ensure the temporary stability of the last sections laid when the hydrostatic frontal thrust on the machine is insufficient;
• this traction is exerted by means of a tractor device connected to the machine by a running cable in the tunnel part already made;
• the machine is equipped with a ballastable compartment to adjust the force of support of the machine on the ground and facilitate its guidance in the vertical plane;
• the soil preparation and / or consolidation treatment or soil lift enhancement tools are disposed in the ballastable chamber;
• the machine is used to also make the access sections not immersed, partially immersed and / or little immersed tunnel.

Each section of tunnel can be built by any appropriate method, such as in particular the assembly of prefabricated parts and in-situ concrete pouring.

In a particular embodiment, each stretch like a ring obtained by assembling segments of section by means of a fixed or movable device placed inside the sealed workspace, joints sealing rings being arranged between the segments.

According to the invention, to compensate locally for the absence or the possible lack of hydrostatic pressure on the tunnel or the front of the machine in access areas where the tunnel is not or little immersed and enhance stability of a current section, it is planned to ensure the compression of the seals arranged between segment segments by transverse prestressing of this section after its establishment.

The invention also relates to a device for implementation of the method.

• une machine apte à fonctionner en immersion qui comporte un espace de travail étanche intérieurement sous pression atmosphérique apte à abriter le personnel et le matériel requis pour la construction d'un tronçon, cet espace ouvert sur la partie de tunnel déjà réalisée permettant de construire un nouveau tronçon ;
• des moyens pour assurer l'étanchéité autour de l'ouverture entre l'espace de travail et le dernier tronçon construit et posé ;
• des moyens pour préparer l'assise du tunnel ;
• des moyens pour provoquer à la demande un déplacement contrôlé de la machine vers l'avant sur le sol sous-marin afin de dégager l'espace requis pour la construction d'un nouveau tronçon ;
• des moyens pour assurer l'étanchéité du tunnel au fur et à mesure de sa construction ;
• des moyens pour contrôler la force d'appui de la machine sur le sol sous-marin et contre le tunnel ;
• des moyens pour apporter à la machine, au travers du tunnel, les constituants et les énergies nécessaires à la construction des tronçons.

This device comprises:

• a machine capable of operating in immersion which comprises a sealed work space internally under atmospheric pressure able to house the personnel and the equipment required for the construction of a section, this space open on the part of tunnel already made allowing to build a new section;
• means for sealing around the opening between the working space and the last section constructed and installed;
• means for preparing the seat of the tunnel;
• means for causing on demand controlled movement of the machine forward on the subsea ground to clear the space required for the construction of a new section;
• means for sealing the tunnel as it is constructed;
• means for controlling the support force of the machine on the underwater ground and against the tunnel;
• means for bringing to the machine, through the tunnel, the constituents and energies necessary for the construction of the sections.

• la machine est équipée de moyens de préparation du sol pour parfaire localement l'état du sol sous-marin, en tant que de besoin pour la cosntruction des tronçons de tunnel ;
• lesdits moyens de préparation du sol comprennent des moyens de nivellement et/ou des moyens de consolidation du sol, robotisés ou non ;
• les moyens de nivellement comprennent des outils de réglage du sol initial ou d'une couche déposée préalablement sur ce sol et éventuellement, des moyens de contrôle et/ou de visualisation en cabine de pilotage de l'état de nivellement ;
• les moyens de nivellement comprennent des outils de nivellement portés par des bras montés à coulisse sur une ou des poutres horizontales ;
• pour régler la force d'appui de la machine sur le sol sous-marin, la machine comporte un compartiment ballastable,
• ledit compartiment ballastable est ouvert vers le bas, les moyens de nivellement étant logés ou retractables dans ledit compartiment ballastable et la machine est équipée de moyens permettant d'injecter à la demande de l'air comprimé dans le compartiment ballastable ;
• le dispositif comprend des moyens pour assurer la force d'appui de la machine sur le tunnel lorsque la charge hydrostatique frontale sur celle-ci est insuffisante ;
• lesdits moyens sont des moyens de traction qui appliquent à la machine une traction exercée vers l'arrière ;
• lesdits moyens de traction comprennent un dispositif tracteur situé à distance en arrière de la machine et relié à la machine par un câble qui court dans la partie de tunnel déjà construite ;
• la machine est équipée de moyens pour exercer sur la machine une poussée afin de la déplacer vers l'avant et maítriser sa trajectoire dans le sens du trajet de pose du tunnel ;
• ledit espace de travail est équipé de moyens pour manipuler et poser des segments préfabriqués de tronçons en vue de construire un tronçon de tunnel ;
• la machine est équipée de vérins disposés pour établir une poussée sur la machine en prenant appui sur le dernier tronçon construit ;
• ledit espace de travail est équipé de moyens pour manipuler des segments préfabriqués de tronçons en vue de construire un tronçon de tunnel ;
• ledit espace de travail étanche est équipé de moyens pour injecter un matériau de remplissage dans le vide laissé par la machine, lors de sa progression, entre le sol et la sous face des tronçons formant le tunnel ;
• la machine comprend un compartiment de lestage ;
• le dispositif comprend des tronçons de tunnel préfabriqués d'une longueur individuelle d'au plus quelques mètres ou des segments de tronçons pour construire de tels tronçons ;
• le dispositif comprend des tronçons de tunnel préfabriqués d'une longueur individuelle généralement inférieure à 3 mètres environ ou des segments de tronçons pour construire de tels tronçons.

In particular embodiments, this device advantageously has one or more of the following characteristics, combined or not:

• the machine is equipped with soil preparation means for locally refining the state of the underwater soil, as needed for the construction of the tunnel sections;
• said soil preparation means comprise leveling means and / or soil consolidation means, robotized or not;
• the leveling means comprise tools for adjusting the initial soil or a layer previously deposited on the soil and possibly control means and / or visualization in the control cabin of the leveling state;
• the leveling means comprise leveling tools carried by arms mounted to slide on one or horizontal beams;
• to adjust the support force of the machine on the underwater ground, the machine has a ballastable compartment,
• said ballastable compartment is open downwards, the leveling means being housed or retractable in said ballastable compartment and the machine is equipped with means for injecting compressed air into the ballastable compartment at the request;
• the device comprises means for ensuring the support force of the machine on the tunnel when the frontal hydrostatic load on it is insufficient;
• said means are traction means which apply to the machine a traction exerted towards the rear;
• said traction means comprise a tractor device located remotely behind the machine and connected to the machine by a cable running in the already constructed tunnel part;
• the machine is equipped with means for exerting on the machine a thrust in order to move it forward and control its trajectory in the direction of the laying path of the tunnel;
• said work space is equipped with means for manipulating and placing prefabricated segments of sections for the purpose of constructing a tunnel section;
• the machine is equipped with jacks arranged to establish a thrust on the machine by building on the last section built;
• said work space is provided with means for manipulating prefabricated segments of sections for constructing a tunnel section;
• said sealed working space is equipped with means for injecting a filler material into the vacuum left by the machine, during its progression, between the ground and the underside of the sections forming the tunnel;
• the machine comprises a ballast compartment;
• the device comprises prefabricated tunnel sections of an individual length of at most a few meters or segments of segments for constructing such sections;
• the device comprises prefabricated tunnel sections of an individual length generally less than about 3 meters or segment segments for constructing such sections.

• d'abri (et de support éventuel) pour la réalisation de la coque constituant le futur tunnel, ou de l'enveloppe externe de cette coque ;
• de déplacement progressif du personnel et du matériel au fur et à mesure de l'avancement du tunnel ;
• de base de travail pour les travaux annexes éventuels (réglage assise, dragage, bourrage sous radier, remblaiement, protection, traitement de sol,...)
• d'étanchéité provisoire entre la partie de tunnel déjà construite et corps de la machine elle-même.

Thus, in its most elaborate embodiment, the invention consists in constructing a tunnel on a submarine ground, in progress, with the aid of a specific submerged machine providing the functions:

• shelter (and possible support) for the realization of the hull constituting the future tunnel, or the outer envelope of this hull;
• progressive movement of personnel and equipment as the tunnel progresses;
• basis of work for possible ancillary works (seat adjustment, dredging, underfloor tamping, backfilling, protection, soil treatment, ...)
• Temporary sealing between the tunnel part already built and the body of the machine itself.

• elle peut notamment être tout ou partie constituée d'éléments préfabriqués ou coulés en place, précontraints ou non ;
• une ou plusieurs files de poteaux ou voiles de séparation peuvent être réalisés de façon à constituer un ou plusieurs files d'appui intermédiaire et/ou,dans le cas de voiles, de séparations étanches à l'air;
• elle peut, comme les tunnels classiques, être constituée de tronçons reliés entre eux par des joints assurant étanchéité et la flexibilité vis-à-vis des déformations de toutes natures du tunnel.
• un second voile peut être réalisé en étanchéité ou en rigidification ;
• elle peut, comme les tunnels classiques, être constituée de tronçons reliés entre eux par des joints assurant étanchéité et la souplesse vis-à-vis des déplacements différentiels.

The structure of the tunnel may be different from that of conventional submerged tunnels, since the constraints are no longer the same:

• it may in particular be all or part of prefabricated elements or cast in place, prestressed or not;
• one or more rows of columns or separation webs can be made to form one or more intermediate support rods and / or, in the case of sails, airtight separations;
• it can, like conventional tunnels, consist of sections interconnected by seals ensuring tightness and flexibility vis-à-vis deformations of all kinds of the tunnel.
• a second web can be made in sealing or in stiffening;
• it can, like conventional tunnels, consist of sections interconnected by seals ensuring sealing and flexibility vis-à-vis the differential movements.

• la figure 1 est un schéma en long d'un exemple de tunnel à réaliser selon l'invention ;
• la figure 2 est une coupe longitudinale d'une partie de tunnel déjà réalisée et de la machine conçue et utilisée selon l'invention pour réaliser le tunnel, et
• les figures 3 à 5 sont des coupes transversales selon les plans 1-1, 2-2 et 3-3 de la figure 2 ;
• la figure 6 est une coupe transversale d'un tronçon courant d'un tunnel terminé, et
• la figure 7 est un schéma longitudinal du tunnel en cours de construction sur lequel est représenté le système de traction vers l'arrière.

Hereinafter, schematically, an embodiment of the invention will be described with reference to the figures of the attached drawing in which:

• FIG. 1 is a schematic diagram of an example of a tunnel to be produced according to the invention;
• FIG. 2 is a longitudinal section of a tunnel part already made and of the machine designed and used according to the invention for producing the tunnel, and
• Figures 3 to 5 are cross sections along the planes 1-1, 2-2 and 3-3 of Figure 2;
• FIG. 6 is a cross section of a current section of a completed tunnel, and
• Figure 7 is a longitudinal diagram of the tunnel under construction on which is represented the rearward traction system.

Figure 1 very schematically represents a tunnel (1) submerged on a floor (2) under a sheet of water (3). This tunnel has two access portions (1a, 1b) open the tunnel in the open air, for example on the banks (4) and (5) of the water table (3), and a main portion immersed (1c). After construction, the tunnel was covered a protective embankment (K) (optional).

The immersed portion, and preferably also the access to open air portions and low immersed portions of the tunnel consist of successive sections of which the cross-section is determined according to the use of the tunnel, in a manner known per se.

For the example, we have shown on the cuts transverse lines in FIGS. 2 to 6, the current section of a two-way two-way double tunnel with transverse profile in bezel shape.

According to the invention, the tunnel is constructed in sections successive ones of an individual length of the order of one meter.

FIG. 2 shows six sections T1-T6 already in place and the beginning of setting up a new section.

The machine (M) used according to the invention has not been represented only very schematically in Figure 3 but of sufficiently for the skilled person.

R-shaped trailers in FIG. 7 are installed at the back of the machine and hitched to it. These trailers, in a manner known in the art of earth tunneling machines, support auxiliary equipment necessary for the operation of the machine, the supply logistics of any kind such as for example the filling mortar, the compressed air, electricity, water, ventilation, voussoirs ... etc.

This machine capable of functioning in immersion includes a work area (6) and a ballastable chamber (7) and if applicable, a load compartment schematized in L. ballast is intended to compensate locally and temporarily insufficient weight of the tunnel with regard to thrust Archimedes.

The work space (6) is peripherally sealed and at the front (in the direction of advancement of the tunnel) and it is connected by a waterproof skirt (27) to the tunnel portion already performed. The workspace is designed to house the staff and all that is needed at least for build the current section to achieve.

For example, the current stretch of tunnel is a ring consisting of prefabricated sectors (or "voussoirs"), these sectors are provided to the workspace, from the shore and as needed, through the tunnel portion already completed, and the workspace is equipped with appropriate (including erector arms) to grasp the voussoirs and put them in place so as to constitute a annular section.

These means may be similar to those used in earth tunneling machines designed to make and install the voussoirs constituting a tunnel ring in a massif drilled.

So we were content in Figure 2 to schematize these means of construction and installation by a pivoting arm transverse (8) slidably mounted on a longitudinal support (8 ') and designed to grab a segment segment and put it on his place of service.

For the sake of clarity, we did not represent the stock of voussoirs waiting to be apprehended and posed.

Only shown in section in Figure 2, one of the voussoirs V of the ring T7.

In the embodiment shown by way of example, the ring consists of eleven voussoirs V spotted (V1) to (V11) in Figure 5 and a central vertical partition (12) which separates the two tubes of the tunnel.

Seals (not shown) ensure way in itself known in the technique of construction by voussoirs of terrestrial tunnels sealing between voussoirs and between sections.

• à pousser la machine vers l'avant pour dégager l'espace nécessaire à la pose d'un tronçon annulaire de tunnel ;
• à l'orienter et la guider sur le sol ;
• à exercer une force de précontrainte longitudinale sur les parois du tunnel en vue de maintenir comprimé les joints entre anneaux et de contribuer à la stabilité longitudinale des derniers anneaux posés.

The work space (6) is equipped with P jacks for:

• pushing the machine forward to clear the space needed to install an annular tunnel section;
• to orient it and guide it on the ground;
• to exert a longitudinal prestressing force on the walls of the tunnel in order to maintain compressed the joints between rings and to contribute to the longitudinal stability of the last rings set.

These cylinders are supported on the one hand on a partition frontal (14) which constitutes a shield in front of the space of work and, on the other hand, on the last section laid. Fact to install a new segment segment, we maintain the pressure cylinders on the segment segments preceding the exception of the one behind the new segment to pose, as seen in Figure 2 where the cylinder P1 has been retracted for the installation of the V segment.

In practice, as seen in Figure 4, there is preferably at least two jacks per segment of section.

In front of the working chamber (6), the machine comprises a ballastable chamber (20) open towards the bottom and towards the front, and which contains arms (21) pivotally mounted back and forth, and movable on one or horizontal beams (22).

These arms carry leveling tools (23).

Most often, as we see best on the FIG. 6, after having prepared a bottom (2) of soil, by example by dredging from the surface, lay a layer excess seat (24) on this bottom and use the leveling tools of the machine to chase forwards and laterally the excess surface portion (24a) of this layer as seen in Figure 2, by adjusting thus the bottom of form.

After laying a section and simultaneously to the progress of the machine, a support layer of the tunnel (25) is injected under the section (fig.5) from the machine which is equipped for this purpose (equipment not shown on figures), to compensate for the thickness of the rear skirt (27) of the machine (see figure 7).

In the working chamber (6) there is provided a device (26) for injecting compressed air into the chamber ballastable, above the water that is there.

This injection makes it possible to control the inclination and the guiding the machine in the vertical plane and adjusting the force of support of the front part of the machine on the ground.

To ensure the pressure of the machine on the tunnel and the compression of the seals arranged between the tunnel sections, in the absence of a hydrostatic thrust sufficient on the front of the machine (in the case of weak tunnel depth and, in any case, in where the tunnel is not immersed or weakly submerged), pulls the machine towards the tunnel, the means of a jack or winch device (28) arranged in the tunnel or on the departure bank and connected to the machine, by example by cables (29).

These means have only been shown schematically in FIG.

When the hydrostatic load on the section is insufficient, we put in place a transverse prestressing sections, schematized by cables (30) in the figure 6.

The sections are eventually linked together, by example by connectors to interlocking, by bolting and / or by bars or cables of temporary prestressing or definitive (31), schematized by points in Figure 6.

The tunnel, normally intended to connect two banks has two access portions which preferably are also carried out by means of the machine.

The invention is not limited to the examples which have been described.

Claims (35)

Method for producing a tunnel partially or totally immersed on a subsea ground, natural or artificial, in which the tunnel is produced by successive tunnel sections, characterized in that a submerged section running on the submarine ground is constructed at means of a machine capable of operating in immersion that is advanced in the water on the submarine soil, on demand, along the path provided for the tunnel, this machine having a sealed work space, under atmospheric pressure, able to house the personnel and the equipment required for the construction and the in-situ installation of the section, in that the tunnel is kept watertight as it is constructed, in that it ensures between the part of the tunnel already made and the workspace of the machine sufficient communication to allow the construction and laying of a new section, and in that the tunnel is used, as and when it is built , for tra nsporter on demand into the machine the constituent elements of the sections. Process according to claim 1 in which one builds the tunnel in successive short sections, preferably one length less than three meters. A process according to claim 1 or 2 wherein prepares the underwater soil by dredging a bottom of soil along the intended path for laying, and then leveling this bottom. Process according to Claim 3, in which seating materials to prepare the underwater soil. A process according to claim 3 in which use is the machine to partially or totally prepare the soil submarine, to the progress, with a view to laying the tunnel, to means of tools integrated in said machine. Method according to one of claims 1 to 5 wherein a soil consolidation treatment is carried out or improvement of the lift of the soil, the progress, by means integrated into the machine or from inside the tunnel already realized. Method according to one of the preceding claims in which the machine is propelled on the underwater ground by push by taking support on the tunnel already made. Process according to claim 7, in which this thrust by means of jacks. Method according to one of the preceding claims in which is exerted on the machine a traction traction directed to the already realized tunnel part, as necessary, to facilitate the guiding of the machine, to compress transverse sealing joints, and ensure the temporary stability of the last sections laid, when the hydrostatic front thrust on the machine is insufficient. A process according to claim 9 in which one exercises this traction by means of a tractor device connected to the machine by cable running in the tunnel part already performed. Method according to one of the preceding claims in which the machine is equipped with a ballastable compartment, to adjust the force of support of the machine on the ground and facilitate its guidance in the vertical plane. A method according to claim 11 wherein is disposed leveling and / or treatment tools consolidation or improvement of soil lift in the ballastable room. Method according to one of claims 1 to 12 wherein each in-situ section is made by assembling segments of sections by means of a fixed or movable device placed at inside the sealed workspace, joints sealing rings being arranged between the segments. The method of claim 13 wherein, strengthens the individual stability of a current stretch and ensures the compression of the seals arranged between segments of the section by transverse prestressing of this stretch after its establishment. Process according to one of Claims 1 to 14 in which is moved step by step on the underwater ground in front of the last stretch laid to clear each time the space needed to set up the next section and to the injection of its final seat. Method according to one of claims 1 to 15 wherein the machine is used to make non-accessible access sections immersed, partially submerged and / or immersed in the tunnel. Device for carrying out a process according to one of Claims 1 to 16, characterized in that it comprises: a machine (M) capable of operating in immersion and which comprises a sealed working space (6) internally under atmospheric pressure, able to house the personnel and the material required for the construction of a section, this open space on the part tunnel already built to build a new section; means (27) for sealing around the opening between the work space and the last constructed section; means (21-23) for preparing the seating of the tunnel; means (P) for causing on demand a controlled movement of the machine forward on the subsea ground to clear the space required for the construction of a new section; means (28, 29) for controlling the machine support force on the subsea ground and against the tunnel; means (R) for supplying to the machine, through the tunnel, the constituents and energies necessary for the construction of the sections. Apparatus according to claim 17 wherein said machine is equipped with soil preparation means (21-23) to improve locally the state of the submarine soil, with a view to the construction of the tunnel sections. Apparatus according to claim 18 wherein said means of soil preparation include means of leveling (21-23) and / or soil consolidation means, robotic means or not. Device according to claim 19 in which the leveling means include adjusting tools (23) initial soil or a layer previously deposited on it ground. Device according to claim 19 or 20, wherein the machine comprises means of control and / or visualization of the leveling state. Device according to one of claims 19 to 21 in 5 which the leveling means comprise tools for leveling (23) carried by sliding arms (21) on one or more horizontal beams (22). Device according to one of Claims 17 to 22 in the machine comprises a ballastable compartment (7) to adjust the force of support of the machine on the underwater ground. Device according to claim 23 and wherein said ballastable compartment (7) is open down and towards the front, the leveling means (21-23) being housed or retractable in said ballastable compartment and the machine being equipped with means (26) for injecting the demand for compressed air in the compartment ballasted. Device according to one of claims 17 to 24 and the means to ensure the support force of the machine on the tunnel when the frontal hydrostatic load on it is insufficient. Device according to claim 25 wherein the said traction means comprise a tractor device (28) located behind the machine and connected to the machine by a cable (29) running in the tunnel part already built. Device according to one of claims 17 to 26 and which includes means (P) for exerting on the machine a push in order to move it forward and control its trajectory in the direction of the laying path of the tunnel. Device according to claim 27, the machine of which is equipped with cylinders (P) arranged to establish a thrust on the machine taking support on the last section built. Device according to one of Claims 17 to 28 in which said work space (6) is equipped with means for manipulate prefabricated segment segments (V) in order to build a tunnel section. Device according to one of Claims 17 to 29 or 30 wherein said sealed work space is equipped with means for injecting a filling material (25) into the emptiness left by the machine, as it progresses, between ground (2) and the underside of the sections forming the tunnel. Device according to one of claims 17 to 30 which comprises transverse prestressing means (30) tunnel sections. Device according to one of the claims 17 to 31 which comprises longitudinal prestressing means (31) tunnel sections. Device according to one of claims 17 to 32 and in which the machine comprises a ballast compartment (L). Device according to one of claims 17 to 33 and which includes prefabricated tunnel sections of one length individual at most a few meters or segments of sections to build such sections. Device according to claim 34 and which comprises prefabricated tunnel sections of individual length typically less than about 3 meters or segments of sections to build such sections.

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