Method for making permeable conduits in subterranean lines of drainage

Claim 1

THE METHOD OF FORMING A PERMEABLE CONDUIT IN AN OPEN TRENCH IN THE FOUNDATION FOR A SURFACE STRUCTURE, WHICH CONDUIT COMPRISES A CORE OF RELATIVELY COARSE INTERSTITIAL MATERIAL, SUCH AS GRAVEL, SEPARATE FROM THE TRENCH WALLS BY LAYERS OF DENSER INTERSTITIAL FILTER MATERIAL, SUCH AS SAND, WHICH COMPRISES THE CYLINDRICAL REPETITION OF THE FOLLOWING STEPS: LAYING AGAINST THE BOTTOM WALL OF THE TRENCH AND CONTINUOUSLY ACROSS THAT ENTIRE WALL A BOTTOM FILTER LAYER OF RELATIVELY DENSE INTERSTITIAL PARTICULATE MATERIAL, SUCH AS SAND, DENSIFYING AND FORMING A CENTRAL CORE PORTION OF SAID BOTTOM LAYER OF SUBSTANTIALLY UNIFORM VERTICAL THICKNESS, LAYING AGAINST THE RESPECTIVE SIDE WALLS OF THE TRENCH, IN SUCH FASHION AS TO BE CONTINUOUS WITH SAID BOTTOM LAYER, SPACED FILTER LAYERS OF THE SAME RELATIVELY DENSE INTERSTITIAL PARTICULATE METERIAL, WHILE MAINTAINING THE RESULTANT SIDE WALL LAYERS OF RELATIVELY DENSE MATERIAL IN POSITION AGAINST THE SIDE WALLS OF THE TRENCH, LAYING A CORE LAYER OF COARSE INTERSTITIAL PARTICULATE MATERIAL THAN SAID RELATIVELY DENSE MATERIAL, SUCH AS GRAVEL, DIRECTLY UPON THE CENTRAL CORE PORTION OF SAID BOTTOM WALL LAYER AND BETWEEN SAID SIDE WALL LAYERS, FINALLY TO PROVIDE SUPPORT OF THE SIDE WALL LAYERS BY DIRECT CONTACT WITH SAID SIDE WALL LAYERS, AND DENSIFYING THE CORE AND SIDE WALL LAYERS, THE STEPS OF LAYING, DENSIFYING AND FORMING THE BOTTOM WALL LAYER PRECEDING THE STEPS OF LAYING THE SIDE WALL AND CORE LAYERS.

Claim 2

THE METHOD OF FORMING A PERMEABLE CONDUIT IN AN OPEN TRENCH IN THE FOUNDATION FOR A SURFACE STRUCTURE, WHICH CONDUIT COMPRISES A CORE OF RELATIVELY COARSE INTERSTITIAL MATERIAL, SUCH AS GRAVEL, SEPARATE FROM THE TRENCH WALLS BY LAYERS OF DENSER INTERSTITIAL FILTER MATERIAL, SUCH AS SAND, WHICH COMPRISES THE CYLINDRICAL REPETITION OF THE FOLLOWING STEPS: LAYING AGAINST THE BOTTOM WALL OF THE TRENCH AND CONTINUOUSLY ACROSS THAT ENTIRE WALL A BOTTOM FILTER LAYER OF RELATIVELY DENSE INTERSTITIAL PARTICULATE MATERIAL, SUCH AS SAND, DENSIFYING AND FORMING A CENTRAL CORE PORTION OF SAID BOTTOM LAYER OF SUBSTANTIALLY UNIFORM VERTICAL THICKNESS, LAYING AGAINST THE RESPECTIVE SIDE WALLS OF THE TRENCH, IN SUCH FASHION AS TO BE CONTINUOUS WITH SAID BOTTOM LAYER, SPACED FILTER LAYERS OF THE SAME RELATIVELY DENSE INTERSTITIAL PARTICULATE METERIAL, WHILE MAINTAINING THE RESULTANT SIDE WALL LAYERS OF RELATIVELY DENSE MATERIAL IN POSITION AGAINST THE SIDE WALLS OF THE TRENCH, LAYING A CORE LAYER OF COARSE INTERSTITIAL PARTICULATE MATERIAL THAN SAID RELATIVELY DENSE MATERIAL, SUCH AS GRAVEL, DIRECTLY UPON THE CENTRAL CORE PORTION OF SAID BOTTOM WALL LAYER AND BETWEEN SAID SIDE WALL LAYERS, FINALLY TO PROVIDE SUPPORT OF THE SIDE WALL LAYERS BY DIRECT CONTACT WITH SAID SIDE WALL LAYERS, AND DENSIFYING THE CORE AND SIDE WALL LAYERS, THE STEPS OF LAYING, DENSIFYING AND FORMING THE BOTTOM WALL LAYER PRECEDING THE STEPS OF LAYING THE SIDE WALL AND CORE LAYERS.