Experimental Study On The Spherical Bulging Deformation Of Geomembrane Under Hoop Constraints

The plain reservoir due to leakage problems more serious, the geomembrane has becomeengineering measures for a new promotion. Although the geomembrane anti-seepageperformance is good, has the advantages of strong adaptability to deformation, corrosionresistance, frost resistance performance is good, but for the bottom of the geomembranehorizontal impervious (reservoir seepage) dams plain reservoir in the initial impoundment ofthe reservoir, the underground water level, seepage, reservoir up wait for a variety of reasons,often easy to make the gas saturated soil aggregation, higher non membrane, and a pressure gasformation in the geomembrane, the geomembrane flatulence phenomenon, even failure, whichcaused inconvenience to the reservoir seepage. A study on the late geomembrane deformationcharacteristics, especially in the geomembrane deformation of spherical bulge under theconstraint of the rings involved too few.This paper analyzes the characteristics and influencing factors of geomembrane bloatingdeformation, based on routine test reference geotechnical membrane device, independentlydeveloped a set of geomembrane bloating deformation testing device, and on the basis of thegeomembrane ring test on deformation to the constraint spherical bulge. Through thegeomembrane inflatable large deformation experiments, summarized the geomembranebloating deformation, the geomembrane bloating deformation of bursting strength,understanding the factors influencing the geomembrane bloating deformation, the mainresearch contents and results are as follows:(1) Geomembrane hoop constraint spherical bulge test apparatus was developed. Thedevice is composed of inflatable device, pressure system, measurement and control systemthree parts. Inflatable device is divided into two parts under film container and flange, betweengeomembrane samples were placed in the membrane under the container and flange, ringconstraint is applied through the flange of the geomembrane samples. Pressurization systemconsists of pneumatic pump supply pressure gas source, and can be adjusted. Measurement andcontrol system is mainly for pressure measurement Wacom top height value.(2) The geomembrane bloating deformation theory analysis, provides the geomembranebloating deformation stress and bending deformation. Through the indoor experiment, summarized the geomembrane bloating deformation. Study of the geomembrane flatulenceunder different test conditions the deformation of the bursting strength, draw the conclusion:the thickness of geomembrane0.1mm burst occurred when the bursting strength of0.0196MPa,broken strain of about0.23, the thickness of geomembrane0.35mm burst occurred when thebursting strength of0.084MPa, broken strain of about0.27, the thickness of the geomembrane0.6mm burst occurred when the bursting strength of0.128MPa, burst strain is about0.33.(3) Experimental study on test equipment aperture, geomembrane thickness, the loadingrate of geomembrane hoop constraint spherical bulge deformation, in-depth analysis ofdifferent factor deformation membrane bulging of soil stress strain relationship, crown heightand bursting strength. According to the influence of experiment equipment aperture ofgeomembrane deformation, recommended diameter of test equipment for20cm geomembranedeformation test equipment.