FIELD AND LABORATORY INVESTIGATION OF DESIGN CRITERIA FOR DRAINAGE WELLS

DESIGN SYSTEMS WERE ANALYZED FOR DRAINAGE WELLS TO CONTROL UNDERSEEPAGE AND PREVENT SAND BOILS LANDSIDE OF LEVEES LOCATED ON PERVIOUS FOUNDATIONS. A SUMMARY OF THE PRINCIPLES OF ANALYSES AND DESIGN OF WELL SYSTEMS ARE PRESENTED AND SPECIFICALLY, FACTORS PERTAINING TO INDIVIDUAL WELLS. A DRAINAGE WELL MUST BE DESIGNED TO: (1) OFFER LITTLE RESISTANCE TO FLOW OF WATER INTO AND OUT OF THE WELL, (2) PREVENT INFILTRATION OF SAND INTO THE WELL AFTER INITIAL PUMPING, (3) WITHSTAND THE EARTH PRESSURES, AND (4) RESIST THE DETERIORATIVE ACTION OF THE WATER AND SOIL. THE APPLICATION OF THESE CRITERIA WERE CONSIDERED TO THE DESIGN OF NON-METALLIC DRAINAGE WELLS. FIELD AND LABORATORY TESTS WERE CONDUCTED ON THE FOLLOWING FOUR TYPES OF DRAINAGE WELLS: (1) BRASS WELL SCREENS, (2) PERFORATED NONMETALLIC PIPES WITH FILTERS, (3) POROUS CONCRETE DRAIN PIPE, AND (4) GRAVEL-FILLED WELLS. THE DISCHARGE EFFICIENCY WAS DETERMINED OF VARIOUS TYPES OF WELLS, THE MAXIMUM SLOT OR MESH SIZE OF BRASS WELL SCREENS AND THE SIZE AND GRADATION OF GRAVEL FILTERS THAT WILL SAFELY DRAIN A GIVEN FOUNDATION SAND. VARIOUS WELLS WERE INSTALLED IN DIFFERENT SAND FOUNDATIONS CONTAINED IN A SEALED CIRCULAR METAL TANK. VARYING PRESSURE HEADS WERE THEN APPLIED AT THE OUTER CIRCUMFERENCE OF THE SAND FOUNDATION AND THE RESULTING FLOW OF WATER AND INWASH OF SAND MEASURED. THE PERFORMANCE OF VARIOUS COMMERCIAL BRASS WELL SCREENS, POROUS CONCRETE PIPES, PERFORATED (CLAY, WOOD, CONCRETE, IRON, AND CEMENT-ASBESTOS) PIPES WITH FILTERS, AND GRAVEL-FILLED WELLS, WAS CHECKED BY A FIELD INSTALLATION OF EXPERIMENTAL DRAINAGE WELLS. PERFORATED OR POROUS NONMETALLIC PIPES WERE SUCCESSFUL AS DRAINAGE WELLS. MATERIALS OF WHICH THE PERFORATED WELLS WERE CONSTRUCTED HAD NO EFFECT ON THEIR RELATIVE DISCHARGE EFFICIENCIES. PROPER INSTALLATION WAS MOST IMPORTANT OF A CORRECTLY DESIGNED FILTER AROUND THE PIPE AND SUFFICIENT PERFORATED AREA. THE PRACTICAL USE OF THE NONMETALLIC TYPES OF DRAINAGE WELLS WAS DEMONSTRATED BY THEIR EFFICIENT OPERATION, BOTH AS TO SAFETY AND DISCHARGE, WHEN PROPERLY DESIGNED AND INSTALLED. DESIGN CRITERIA ARE PRESENTED FOR THE GRAVEL FILTERS FOR THE PERFORATED PIPES. GRAVEL-FILLED WELLS APPEAR TO HAVE A LOW DISCHARGE EFFICIENCY. THIS IS BECAUSE OF THE FRICTIONAL RESISTANCE ENCOUNTERED BY THE WATER FLOWING UPWARD THROUGH THE GRAVEL IN THE WELL, AND THE RESISTANCE ENCOUNTERED IN FLOWING TO AND THROUGH THE RELATIVELY FEW PERFORATIONS IN IN THE CASING. THE EFFECT OF FRICTION AND VELOCITY HEAD LOSSES IN THE RISER AND DISCHARGE PIPES OF A WELL SCREEN ON REDUCING ITS DISCHARGE EFFICIENCY WAS DEMONSTRATED. THE PRACTICALITY WAS DEMONSTRATED OF DRAINAGE WELLS FOR REDUCING SUBSTRATUM PRESSURES AND CONTROLLING UNDERSEEPAGE. THE SPACING OF THE DRAINAGE WELLS WAS OBSERVED TO HAVE A MATERIAL EFFECT ON THE EFFICIENCY OF THE SYSTEM. THE DISCHARGE FROM THE DRAINAGE WELL SYSTEM WAS FOUND TO BE PROPORTIONAL TO THE RESERVOIR POOL ELEVATION, PROVIDED THE TAIL WATER BELOW THE DAM REMAINED CONSTANT.

  • Supplemental Notes:
    • No 195-1, 24 FIG, 7 TAB, 25 PHOT
  • Publication Date: 1942-10-1

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  • Accession Number: 00204139
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 18 1994 12:00AM