Study on Functional Characteristics of Geomembranes as New Construction Materials by Centrifugal Model Tests

土工材料，特别是高密度聚乙烯（HDPE）新材料，有望用作垃圾填埋场的衬垫。因为，从强度和耐化学腐蚀性的角度来看，它比普通橡胶更好。本课题的目的是通过对HDPE土界面的直剪试验、土工膜埋置地基的拉拔试验和垃圾固结摩擦拉力估算试验，为设计方法的发展提供基础数据。随后的拉力通过摩擦与固结的废物。揭示了以下几点：1.小尺寸样品（如直径60 mm）可能高估土壤-HDPE界面的剪切强度。最好是300 mm的大样品尺寸。2.土-HDPE界面的摩擦强度系数为0.3 ~ 0.6，低于土-土工织物界面的摩擦强度系数。3.推导了土工膜拉拔试验中拉拔力与变形的关系式。结果表明，对于给定的拔出力，摩擦系数越大，覆盖土越厚，变形越小。4.用离心机估算固结摩擦引起的土工膜拉伸力，可大大节省试验时间。例如，在离心试验中只有12小时对应于2年的实际现场行为。5. HDPE中高岭土固结摩擦力的平均值为0.06kgf/cm ~ 2。太低了。实际废物，如油炸灰，可能导致更高的价值。希望对此类材料进行测试。

The geomemgrane, especially new material called HDPE (High Density Poly-Etylen), is expected to be employed as a liner of waste landfill. Because, it is preferable to ordinary rubber from a point of viev of strebgth an dchemical survivability. The object of this project is to get basic data which are useful to develop a design method by performing the experiments such as direct shear tests for soil-HDPE interface, pull-out tests of geomembrane form embedding ground and tests for estimating of tensile force by friction with consolidation fo waste. the following of tensile force by friction with consolidation of waste. the following are revealed : 1. Small size sample such as 60-mm diameter can over-estimate a shear strength of soil-HDPE interface. Large sample size of 300-mm is preferable. 2. The efficiencies of frictional strength for soil-HDPE Iinterface is 0.3 - 0.6, which is lower than those of soil-geotextile interface. 3. Equation showing a relation between pull-out force an deformation at fromt of geomembrane in a pull-out test was derived. It suggests that the higher a friction coefficient and the thicker the cover soil, the smaller a deformation for a given pull-out force. 4. Use of centrifuge for estimating a tesile force in geomemgrane induced by friction with consolidation can save the testing time considerably. For example, only 12 hours in cetrifuge tests corresponds to 2 years in actua field behavior. 5. The tnsile force in HDPE induced by friction of kaorin clay's consolidation is 0.06kgf/cm2 on the average. This is too low. Actual waste such as fry-ash may result in higher vales. It is expected to do a test for such the materials.