Catchwater drain, excavating structure and method of construction

Claim 1

A process for construction of catchwater drains, drain ribs, supporting ribs or similar structures comprising the steps of: (a) making a first trench-section having a bottom and side faces to its full depth in the soil along a proposed traceline of said catchwater drain; (b) placing a first inflatable hose of a temporary supporting structure into said first trench-section; (c) inflating said first hose to an internal pressure sufficient to ensure stability of the faces of said first trench-section; (d) making a second trench-section to its full depth in the soil adjacent to said first trench-section along said traceline; (e) placing a second inflatable hose of said temporary supporting structure into said second trench-section; (f) inflating said second hose to a desired internal pressure, thereby ensuring temporary stability of faces of said second trench-section; (g) deflating said first hose in said first trench-section; (h) removing the first hose and placing at the bottom portion of the volume occupied by said deflated first hose a first water collecting-aquiferous block laid on the bottom of said first trench-section, said block being placed at least partly in a relatively impermeable soil layer thereby filling out a substantial portion of the lower area of said first trench-section; (i) placing at least one first suction body on top of said first water collecting aquiferous block, said suction body consisting of granular material filled into a filter bag, said filter bag filled to an upper part of said first suction body in the vicinity of the groundsurface; and (j) making another trench-section using the steps (a) to (i) along the traceline until the catchwater drain is completed.