with the blocks equipped with coupling means for the plinth block 950 said rectangular prisms 100 are separated by two trapezoidal prisms 200 whose cross section is a rectangular trapezoid 201 this being its profile with the face of said trapezoidal prism 200 corresponding to the angled side 202 of the rectangular trapezoid 201 profile facing downwards trapezoidal prisms 200 are arranged opposite to each other on one of their faces said faces corresponding to the minor base 203 of the rectangular trapezoid 202 profile of each trapezoidal prism 200 between said faces there is a cavity 204 in the central part of the bottom surface of the plinth block 950 corresponding to the lower faces of the trapezoidal prisms 200 two slopes 205 are formed at an angle that opens and rises from the ends of the plinth block 950 towards its center where the cavity 204 is said slopes 205 not crossing with the top surfaces of the trapezoidal prisms 200 the lowest point of the slopes 205 is elevated relative to the lower edge 121 of the two rectangular prisms 100 so that when placing the plinth block 950 on the plinth surface 800 the lower edge 121 of the two rectangular prisms 100 is laid directly on said plinth surface 800 without any intermediate space but leaving a space between said plinth surface 800 and the surface of the slopes 205 thereby forming a cavity 300 between the plinth surface and the slopes 205 where.