Geogrid Creep Performance

Geogrid is a new type of geosynthetics,which has good properties including light weight ,strong strength ,low rate of elongation, resistivity against acidity and basicity.It can achieve better economic results for the use of geogrid in civil construction.But the research on manufacture and properties of geogrid is far less than the production and application, especially the study on geogrid's creep behavior remains vacancy.In this paper,the writer does some study on the creep of geogrid.The study consists of two part ,one is measuring and judging the creep behavior,another is finding some ways to raise the resistivity against creep of geogrid .Under the condition of a certain time,the creep strain is measured at a certain temperature and a certain loading.Through simulating the creep data measured with functional relation,we get two equations:one is relationship of stain and time;another is that of stress and time.Based on equations of time-temperature and time-stress,long-range creep behavior of geogrid is deduced.Through building creep model based on creep behavior of geogrid and analysing model with finite element method,we find the distribution of stress and strain in geogrid, and max value of stress and strain.The result will give advice to improve the processing of geogrid and be more precise to predict long-range creep behavior.Some parameters from material and processing which influence the creep behavior of geogrid are found and some ways to raise the resistivity against creep are given.We come to the three conclusions.Firstly, finalizing the shape of geogrid with cool water improves the strength and the resistivity against creep.Secondly, the way of manufacturing geogrid with HDPE filled with caltalc decreases the strain and raises the resistivity against creep.Thirdly, we compare the result of raising the resistivity against creep of former way with that of laterways and find that the way using caltalc is better than the way finalizing the shape of geogrid with cool water.In addition,the capacity of caltalc must be moderate to improve the strength and resistivity against creep.