HDPE土工格栅加筋土结构的筋材长期强度研究

Research on the Long-Term Tensile Strength of HDPE Geogrids in Reinforced Soil Structure

土工格栅筋材长期强度是加筋土结构设计中的重要参数,其受土工格栅在施工及其使用过程中的施工损伤、蠕变和生物化学侵蚀等因素的影响.为了确定高密度聚乙烯(HDPE)土工格栅筋材在加筋土结构使用过程中的长期强度,进行了相关室内外试验研究,分析了土工格栅在土体介质和空气介质中的拉伸强度及拉伸速率对其强度特性的影响,计算了5种不同级配填料介质中土工格栅施工损伤折减系数,确定了典型土工格栅的蠕变试验方法及蠕变折减系数,探讨了土工格栅的老化折减系数.

The long-term tensile strength of geogrids in reinforced soil structure is an important design parameter.The reduction factors of geogrids,such as installation damage,creep,chemical and microbiological degradation during construction and using in the soil must be considered to decide the long-term tensile strength.According to the indoor and outdoor tests,the strength of geogrids in soil-confined and in air is compared,and the tensile properties of high-density polyethylene(HDPE)geogrids with different strain rates are studied.In addition,the installation damage reduction factor in five poorlygraded granular fill is calculated.The creep test method and creep reduction factor are raised with typical geogrids.Finally,the durability reduction factor is discussed.