Structural performance of plastic pipe used for landfill leachate collection
With the development of stricter regulations pertaining to the siting and design of sanitary landfills, the current trend has been toward increasing the height of existing landfills to accommodate the disposal of solid waste. The increased height of the landfill translates into a higher load on the leachate collection pipes at the base of the landfill. The purpose of this project was to apply large loads to 6 inch diameter PVC and HDPE plastic pipes. These loads, applied in increments of approximately 15 tons, reached a maximum exceeding 200 tons, simulating a landfill height of approximately 175 assuming a waste density of 60 pcf. These loads were applied by two hydraulic cylinders mounted on a large steel frame. These pipes were tested in typical landfill installation modes. Six inch PVC, Schedule 80 perforated pipes were tested in both the positive and negative projection mode, and a 6 inch HDPE, SDR 11 perforated pipe was tested in the positive projection mode. Strains in the longitudinal and circumferential directions were measured at approximately the midspan of the pipe. The deflection was measured by rotating a LVDT near to the section at which the strain gages were placed. The output voltages from these devices were recorded using a portable data acquisition system. The PVC pipe tested in the negative projection mode and the HDPE pipe tested in the positive projection mode showed maximum deflections of 7.76% and 3.65%, respectively. These measured deflections were compared to deflections predicted using the Modified Iowa Formula. Thrusts and bending moments in the pipe wall were also determined. The thrusts exhibited negative values at most sections of the pipe. The bending moments reached maximum values at the pipe crown of 186 lb*in/in and 81.57 lb*in/in for the PVC and HDPE pipe, respectively.
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:negative projection mode hdpe pipe tested landfill leachate perforated pipes
Date of Publication:01/01/1992