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

geomemgrane，特别是称为HDPE（高密度聚乙烯）的新材料，有望被用作垃圾填埋场的衬垫。因为，从强度和化学生存能力的角度来看，它优于普通橡胶。本课题的目的是通过土-高密度聚乙烯界面的直剪试验、土工膜形式埋地的拉拔试验和土与固结摩擦拉伸估算试验等试验，获得有助于制定设计方法的基础数据。下面的拉伸力由摩擦与废石固结而成。揭示了以下内容：直径为60mm的小尺寸试样会高估土- hdpe界面的抗剪强度。300mm的大样品尺寸优先考虑。2. 土- hdpe界面的摩擦强度效率为0.3 ~ 0.6，低于土-土工织物界面。3. 推导了土工膜拉出试验中拉出力与变形之间的关系式。结果表明，在一定的拉拔力作用下，摩擦系数越高、覆盖土越厚所产生的变形越小。4. 利用离心分离机测定土工结构中摩擦固结引起的抗拉力，可以大大节省试验时间。例如，只有12小时的离心机试验相当于2年的实际现场行为。5. 高岭土固结摩擦对HDPE产生的弹性力平均为0.06kgf/cm2。这太低了。实际的废物，如炸灰，可能会导致更高的数值。预计将对这些材料进行测试。

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.