System for excavating a trench in submerged ground and associated excavation method

Abstract

A system for excavating a trench in ground submerged in water is described. The system includes an excavation device comprising moving means capable of moving the excavation device on the submerged ground and excavation means capable of being supplied with pressurized water and excavating the submerged ground using the pressurized water, The system also includes control means configured to control the moving means and supply means configured to supply pressurized water to the excavation means, where the supply means can include at least one water-jet turbine.

1 . A system for excavating a trench in ground submerged in water, said system comprising:
 an excavation device comprising:
 locomotion means able to move said excavation device over the submerged ground, and 
 excavating means able to be supplied with pressurized water and to excavate the submerged ground using the pressurized water, 
   control means configured to control the locomotion means, and   supply means configured to supply pressurized water to the excavating means, wherein the supply means comprise at least one water-jet turbine, said at least one water-jet turbine being positioned on floating means adapted to position a water intake of said at least one water-jet turbine immersed in the water.   
     
     
         2 . The system of  claim 1 , further comprising at least one watercraft comprising said at least one water-jet turbine and the floating means. 
     
     
         3 . The system of  claim 1 , further comprising detecting means able to detect a pipeline positioned on the submerged ground, wherein the control means are able to control the locomotion means to obtain excavation of a portion of the submerged ground underneath the pipeline. 
     
     
         4 . The system of  claim 1 , further comprising:
 first acquisition means able to obtain a position of the excavation device, and   second acquisition means able to obtain a depth of the water at said position of the excavation device, via transmission and reception of acoustic waves, wherein the control means are able to control the locomotion means as a function of the position obtained and/or the depth obtained.   
     
     
         5 . The system of  claim 4 , wherein:
 the control means are positioned on a vessel,   the second acquisition means are positioned on a surface of the water at the position of the excavation device, wherein the second acquisition means are able to transmit the depth obtained to the control means via radio waves.   
     
     
         6 . The system of  claim 1 , wherein the excavation device is a trencher. 
     
     
         7 . The system of  claim 1 , further comprising first connecting means able to connect the excavating means to the at least one water-jet turbine, in the form of a line having a length shorter than thirty meters. 
     
     
         8 . A method for excavating a trench in ground submerged in water, the method comprising:
 controlling, by control means, locomotion means of an excavation device, to move said excavation device over the submerged ground, and   supplying pressurized water, by supply means, to the excavating means of said excavation device, the submerged ground being excavated by the excavating means using the pressurized water, the supply means comprising at least one water-jet turbine, said at least one water-jet turbine being positioned on floating means adapted to position a water intake of said at least one water-jet turbine immersed in the water.   
     
     
         9 . The method of  claim 8 , further comprising detecting a pipeline positioned on the submerged ground, the locomotion means being controlled so that the excavating means excavate a portion of the submerged ground underneath the pipeline. 
     
     
         10 . The method of  claim 8 , further comprising:
 obtaining a position of the excavation device, and   obtaining a depth of the water at said position of the excavation device, by transmitting and receiving acoustic waves, wherein the controlling of the locomotion means is performed as a function of the position obtained and/or the depth obtained.   
     
     
         11 . The method of  claim 8 , wherein:
 the control means are positioned on a vessel, and   acquisition of the depth is obtained by second acquisition means, positioned on a surface of the water at the position of the excavation device,   the method further comprising transmission of the depth measured by the second acquisition means to the control means via radio waves.