砂土围压下的废轮胎拉拔试验评估

Experimental research on pullout test of waste tire with sand confinement

由于轮胎具有高强度与耐久特性,将废旧轮胎作为加筋土壤结构物的加筋材料,应是21世纪处理废轮胎的一个方向。由于轮胎为一立体结构材料,其所造成的边界影响将不同于普遍使用的平面式土工织布与土工格栅,藉由柔性前壁可有效改善砂土挤压所造成的前壁效应。以完整和一侧被切割轮胎进行试验,在前壁与侧壁效应良好的控制下,经切割的废轮胎能与砂土紧密夯实并增加受正向应力面积,其拉出阻抗优于完整轮胎。当轮胎减少一侧的胎唇钢丝,切割轮胎发生的变形量大于完整轮胎的变形量。以不同的连接材料评估两个轮胎的加筋成效,其结果显示轮胎与轮胎间的拉伸变形将影响其拉拔阻抗,需藉由低延伸性材料与刚性夹片限制轮胎的变形。因此,采用废旧轮胎进行加筋填筑时,需注意轮胎产生的沉陷变形量,此工法可用于边坡或路堤的加筋工程。

Since tire have characteristics of extremely high strength and high durability,using the waste tires to adopt as the reinforced element in the reinforced structure will be a good application to treat the waste tires.Pullout resistant behavior is the major topic to be evaluated in this reinforcement application.Since the 3D geometry of tire is different from traditional planar geosynthetics（such as geotextiles and geogrids）,the boundary condition and interface interaction are also be different from current theoretical models.To evaluate the performance of waste tire as reinforcing element,the large size of pullout test system is therefore to be need in this study.Tires with and without one side wall cut are tested and compared in this study for their performances.Flexible materials were also used in this study to eliminate the extrusion of filled sands caused by front wall effects.After the front wall effects has been successful studied and controlled,the test results showed the cut-tire provide better compaction performance of filled sands and increase the area subjected to normal stress.It exhibits the significantly better pullout resistance than the reinforced soil mass with the tire without cut.When the cut-tire to reduce the side of bead wire,it results the larger deformation than tire without cut.To evaluate the reinforcing effect of two connected tires,the tensile elongation from the inter-zone of two tires is the major influence.Needs to restrain the tire deformation by lower elongation materials and rigid clips for connection.The findings provide some better knowledge to adopt the waste tires in reinforced earth application.In addition,from the results observation,significant settlement may be occurred during reinforcement construction process.This will be also a important consideration for the design approach.