Patent Publication Number: US-2017356156-A1

Title: Caisson

Description:
OBJECT OF THE INVENTION 
     The present invention relates to the field of civil construction and more specifically to that of maritime works. 
     It is proposed a caisson for maritime works comprised of a plurality of voussoirs of polymer material forming horizontal segments which are joined to each other to form the lateral wall of the caisson, and a base joined to the lateral wall and which may be of any type of material, preferably metallic or polymeric. 
     BACKGROUND OF THE INVENTION 
     In the field of maritime works is of particular note the construction of seawalls in ports, which are structures that enable the reduction of the action of the sea swell on the ports where they are installed. 
     Among this type of construction are known, for example, vertical seawalls which are vertical walled that are monolithic and have impermeable walls. This type of seawall is generally constructed with reinforced concrete caisson and has a gravitational performance, that is, the stability of the caisson is based on its own mass. 
     The differentiating characteristic of vertical seawalls with respect to other types of seawall (such as, for example, embankments consisting of differently-sized artificial and/or natural riprap and generally with concrete shoulders) is that they reflect the practical entirety of the sea swell energy, reflecting the swell action as a rigid vertical monolithic wall. Vertical barriers must be sufficiently resistant to sliding and overturning. 
     Caissons for vertical seawalls may also be employed for the construction of barriers and quays for the mooring of ships. Likewise they may be used as filling containment for obtaining surface platforms. 
     Currently, concrete caissons are manufactured directly in the sea, afterwards are transported and sunk at their desired location. The most important technical problems associated with this procedure concern the large quantity of resources and machinery required for the construction of the caissons directly in the sea. 
     Different proposals for materials and construction methods of the caissons for maritime works to be used in the construction of vertical seawalls are known in the state of the art. Known examples are the caissons fabricated by the union of voussoirs laterally linked to each other and anchored into a slab. 
     The technical problem associated with this solution is that, for some embodiments, particularly the embodiments where the caissons have a very high height, the caisson obtained is not sufficiently resistant. This is due to the fact that in some cases the voussoirs of which it is comprised present sagging problems. 
     Another technical problem associated to this embodiment in the cases described is that the difficulty of the transport from the factory to the port of the elements forming the caisson is increased since the voussoirs have a great height. 
     DESCRIPTION OF THE INVENTION 
     The caisson for maritime works described herein is especially designed to be installed in vertical seawalls, and allows solving the problems described above. 
     This is a prefabricated caisson formed by a base and a plurality of voussoirs which generate a plurality of horizontal segments to be joined together to form thus a lateral wall of the casing which is attached to the base. 
     In other words, an important essential characteristic of the caisson of the present invention is that at least one lateral wall of the caisson is comprised of a plurality of voussoirs joined to each other, forming horizontal segments. This is to say, the total height of the caisson is obtained by joining, one above the other, a plurality of horizontal segments. 
     In order to prevent the existence of leaks from and into the interior of the caisson, it is necessary that all the joints between the voussoirs forming the horizontal segments are perfectly sealed. Likewise, it has to be guarantee the correct seal at the joints between the horizontal segments. 
     Due to the fact that the lateral sides of the caisson are formed by horizontal segments, the links between voussoirs are simplified, substantially improving their structural performance and their construction. 
     Furthermore, as the height of the voussoirs is less than that of the casing because the total height of the casing is obtained by the union of several horizontal segments, the transport of said items may be performed in a simpler and more economical manner. 
     Besides, in an example of a preferred embodiment, the sections are fabricated in polymeric material reinforced with fibre and the base is fabricated in a metallic material. The base is preferably metallic as it is used as lost formwork with a lower cost than fabricating it in polymer material as is the case of the lateral wall. 
     In an example of an embodiment, the caisson further comprises a plurality of vertical columns attached to the voussoirs and which may be used as stiffeners or as formwork to be filled with reinforced concrete, and which transmit to the base the loads generated by the placement of a slab of concrete, should this be required, as a cover for the main space to be filled with ballast. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       As a supplement to the description made herein, and for the purpose of aiding the better understanding of the characteristics of the invention, in accordance with a preferred example of a practical embodiment of the same, a set of drawings is attached wherein, by way of illustration and not limitation, the following is portrayed: 
         FIG. 1  shows a perspective view of the caisson for maritime works with a plurality of voussoirs arranged so as to form vertical joints leading from the upper extremity of the caisson to the base of the same. 
         FIG. 2  shows a perspective view of the caisson for maritime works with the lateral wall sections arranged in a staggered manner. 
         FIG. 3  shows an exploded view in which the horizontal segments formed by adjacent voussoirs. 
         FIG. 4  shows an exploded view of the caisson for maritime works of  FIG. 1 . 
         FIG. 5  shows a perspective view of the caisson for maritime works where the vertical columns are used as formwork and are filled with reinforced concrete. 
         FIG. 6  shows a perspective view of the caisson for maritime works where some of the vertical columns are used as stiffeners and others as formwork filled with reinforced concrete. 
         FIG. 7  shows a view of a horizontal chemical joint between voussoirs of contacting horizontal segments. 
     
    
    
     PREFERRED EMBODIMENT OF THE INVENTION 
     An example of an embodiment of the present invention is described below with the aid of  FIGS. 1-7 . 
     As may be observed in  FIG. 1 , a caisson for maritime works is proposed, comprising a base ( 1 ) and at least one lateral wall ( 2 ) attached to the same and formed by a plurality of voussoirs ( 3 ) within which a main space ( 4 ) is defined, intended to receive ballast material.  FIG. 2  shows a caisson as the one of  FIG. 1 , but where the voussoirs ( 3 ) are arranged in a staggered manner. 
     The voussoirs ( 3 ) have an upper side ( 5 ), a lower side ( 6 ) and lateral sides ( 7 ) and are arranged with the lateral sides ( 7 ) of adjacent voussoirs ( 3 ) attached to each other forming horizontal segments ( 8 ), as may be observed for example in  FIG. 3 . Said horizontal segments ( 8 ) are joined to other identical horizontal segments ( 8 ) to define the lateral wall ( 2 ) of the casing by means of the union of the upper sides ( 5 ) and lower sides ( 6 ) of the voussoirs ( 3 ) forming the same. Preferably, the voussoirs ( 3 ) are fabricated in a fibre-reinforced polymer material. More specifically, the fibre in the polymer material may be selected between glass fibre and carbon fibre, with epoxy, polyester or vinylester resin. 
       FIG. 4  shows an exploded view of the caisson wherein the voussoirs ( 3 ) and the base ( 1 ), which are the essential elements, can be seen. Other elements comprised by the caisson in preferred embodiments, such as the vertical columns ( 9 ) and the primary stiffeners ( 10 ) in the base ( 1 ) can also be seen. 
     The base ( 1 ) has a geometric shape which coincides with the geometric shape of the horizontal segments ( 8 ). In an example of an embodiment, the base ( 1 ) has a polygonal configuration and the lateral wall ( 2 ) has a polygonal prismatic configuration. In a preferred embodiment of the invention, the lateral wall ( 2 ) has a cylindrical configuration and the base ( 1 ) has a circular configuration. In another embodiment, the base ( 1 ) further comprises primary stiffeners ( 10 ) in order to increase its structural strength. 
     Preferably, the base ( 1 ) is fabricated in parts which are attached together to form a single item. In an example of a preferred embodiment said base ( 1 ) is fabricated in a metallic material. In another embodiment the base ( 1 ) is fabricated in a fibre-reinforced polymer material. 
     To reinforce the caisson it comprises a plurality of vertical columns ( 9 ) joined to the voussoirs ( 3 ). Said vertical columns ( 9 ) may be reinforcing elements acting as stiffeners or may be used as formwork. In this second case, where the vertical columns ( 9 ) are used as formwork, they may be permanent formwork or temporary formwork with an empty cavity in their interior intended to be filled with reinforced concrete (this concrete may be reinforced with fibres or with structural steel). In this way, a concrete column is formed, which enables transmission of the loads of the caisson. More specifically, at the upper surface of the caisson a concrete slab is laid, this being the element which covers the main space ( 4 ) formed between the lateral wall ( 2 ) and the base ( 1 ) of the caisson. The vertical concrete columns ( 9 ) enable the transmission of loads from the upper slab (which is also of concrete) to the base ( 1 ) of the caisson, allowing the voussoirs ( 3 ) of the lateral wall ( 2 ) acting enclosing the ballast in the main space ( 4 ) of the caisson. 
       FIG. 5  shows a view of the caisson in an embodiment comprising a plurality of vertical columns ( 9 ) arranged within the main space ( 4 ), acting as formwork and filled with reinforced concrete.  FIG. 6  shows an embodiment where some of the vertical columns ( 9 ) are being used as formwork, with reinforced concrete in their interior, and others are acting merely as stiffeners. 
     The joints between the voussoirs ( 3 ) may be mechanical joints or chemical joints ( 11 ). Chemical joints are comprised of adhesives, and more specifically, brine-resistant adhesives. This type of joint may be seen for example in  FIG. 7 , where the horizontal joint formed by the coupling of two voussoirs ( 3 ) arranged one above the other has been depicted. Moreover, mechanical joints preferably comprise the use of rivets or bolted couplings. The arrangement of the voussoirs may be performed in such a way that the joints between voussouirs forming stacked horizontal segments are aligned, or said stacking may be performed so that the assembly of different horizontal segments generates a staggered arrangement of the joints between the voussoirs (as may be seen in  FIG. 2 ). Likewise, in a preferred embodiment, the joints between the vertical columns ( 9 ) and the voussoirs ( 3 ) are chemical joints or mechanical joints. 
     An example of an embodiment of the caisson it further comprises a plurality of secondary stiffeners arranged within the main space, joined to the voussoirs. This enables an increase in the strength of the caisson and an improvement in its structural resilience. 
     Likewise, a procedure for the assembly of a caisson for maritime works as described above is also an object of the present invention. 
     In a first example of an embodiment, the procedure for the assembly of the caisson comprises the following stages:
         joining a voussoir ( 3 ) to the base ( 1 ) by its lower side ( 6 ),   joining voussoirs ( 3 ) adjacent to the aforementioned voussoir by their lateral sides ( 7 ) and to the base ( 1 ) by their lower sides ( 6 ) so as to form a first horizontal segment ( 8 ),   joining a voussoir ( 3 ) by its lower side ( 6 ) to the upper side of the voussoirs ( 3 ) of the horizontal segment ( 8 ) immediately below,   joining voussoirs ( 3 ) adjacent to the aforementioned voussoir by their lateral sides ( 7 ) and to the horizontal segment ( 8 ) immediately below by their lower sides ( 6 ) so as to form the next horizontal segment ( 8 ),   repeating the above stages until the lateral wall ( 2 ) is completed.       

     In an example of an embodiment, said assembly procedure is comprised of the following stages:
         joining the mutually adjacent voussoirs by their lateral sides ( 7 ) to form the horizontal segments ( 8 ),   joining one horizontal segment ( 8 ) to the base ( 1 ) by the lower sides ( 6 ) of the voussoirs ( 3 ) forming said segment,   joining together the remainder of the horizontal segments ( 8 ) to form the lateral wall ( 2 ).       

     In another example of an embodiment, said assembly procedure is comprised of the following stages:
         joining adjacent voussoirs together by their lateral sides ( 7 ) to form the horizontal segments ( 8 ),   joining together the horizontal segments ( 8 ) by the upper sides ( 5 ) and lower sides ( 6 ) of the voussoirs of which they are formed, so as to form the lateral wall ( 2 ),   joining the lateral wall ( 2 ) to the base ( 1 ) by joining the lower sides ( 6 ) of the voussoirs ( 3 ) forming the lowest horizontal segment to the base ( 1 ).       

     The procedure may further comprise a stage of placing vertical columns ( 9 ) within the main space ( 4 ) of the casing and attaching the vertical columns ( 9 ) to the voussoirs ( 3 ). These vertical columns ( 9 ) are arranged and attached to the voussoirs ( 3 ) to reinforce the joints and to increase structural strength. 
     Likewise to improve the structural strength of the caisson, the assembly procedure may include a stage of joining the primary stiffeners ( 10 ) to the base by means of chemical or mechanical joints. 
     Finally, the assembly procedure may comprise, subsequent to the stages of assembly of the caisson at the port (as described above), the following stages:
         launching the caisson in the sea,   ballasting the caisson, partially filling the main space ( 4 ),   towing the caisson by sea to its final position,   sinking the caisson by filling the main space ( 4 ).       

     Therefore, as has been described above, the caisson is assembled at the port, this being the location closest to the final position in which it is to be installed (this being in the sea). Thus, the elements which form the caisson may be transported independently from the factory to the port. This enables speeding up the transport operations as the items to be transported are much smaller and lighter than the complete assembly. This facilitates travel operations and reduces associated costs, in addition to reducing timings. 
     Subsequently, once at the port, the assembly of the caisson is executed; once assembled, it is launched in the sea and taken to the final location for its installation. Said assembly could also be executed at the factory in the event that the users should prefer this for a particular reason.