In recent decades, considerable attempts through geotechnical study have been made to reduce plastic waste by recycling and reuse. The aim of this study was to reuse waste plastic mixed with sand for geotechnical application. To this end, large-scale oedometer experiments were carried out to examine the compressibility of Bandar-e Anzali sands stabilised with plastic-waste-originated high-density polyethylene (HDPE). Bandar-e Anzali is a populated coastal city in the vicinity of the Caspian Sea (northern Iran). Large-scale oedometer and direct shear tests were performed to study the applicability of HDPE chips mixed with sand at various HDPE contents (0, 2, 4, 6 and 8%). Based on the experimental tests, the addition of plastic waste to the soil improved the soil's strength, significantly raised its compressibility and decreased the undrained elasticity modulus. By adding 8% HDPE, the constrained compression modulus decreased to 50% at a pressure of 300 kPa due to the elastic deformability of HDPEs. However, at higher relative density, adding HDPE by more than 4% did not affect the coefficient of lateral earth pressure at rest.

中文翻译：

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砂-HDPE混合物的压缩特性及侧向土压力系数

近几十年来，人们通过岩土工程研究进行了大量尝试，通过回收和再利用来减少塑料废物。本研究的目的是将与沙子混合的废塑料重新用于岩土工程应用。为此，进行了大规模的里程计实验，以检查用塑料废物来源的高密度聚乙烯 (HDPE) 稳定的安扎利港砂的可压缩性。安扎利港是里海（伊朗北部）附近人口稠密的沿海城市。通过大型流量计和直剪试验来研究不同 HDPE 含量（0、2、4、6 和 8%）的 HDPE 碎片与沙子混合的适用性。根据实验测试，向土壤中添加塑料废物提高了土壤的强度，显着提高其压缩性并降低不排水弹性模量。添加 8% HDPE 后，由于 HDPE 的弹性变形能力，在 300 kPa 压力下约束压缩模量下降至 50%。但在较高相对密度下，HDPE添加量超过4%并不会影响静止侧向土压力系数。