Rereach On Mechanism And Long-term Prediction Of Geomembrances Creep

Geomembranes are important application materials in anti-seepage and flood control project. Their creep characteristic is an important factor that affects engineering stability, therefore, it is necessary to study the creep characteristic. In order to do some research in this field, creep testing experiment of geomembranes using RB-0408 Creep Testing Instrument (suitable for geotextile and geomembrane) was designed, which adopted 20%, 30%, 40%, 46%, 50%, 60% limited load and lasted 5000 hours; to study the method of creep testing and data processing, as well as analyze creep mechanism of composite geomembranes through experiment, and predict the creep deformation in long-term. The main research work is as following:1. Analysis on creep test of geomembraneBased on the creep test of geomembranes which adopted different limited load and used RB-0408 Creep Testing Instrument, the creep mechanism of geomembranes and other high molecular polymer was revealed, and creep mechanical model of geomembrane is build by non-linear mechanics methods and modem mathematical methods.2. Theoretical analysis on creep behavior of geomembraneIn the view of high polymer physics, the micro-explanation on stress-strain behavior of geomembranes viscoelastic is given by systematic analyzing the creep process of geomembrane and other polymer.3. Research on experience model of creep characteristicsBased on geomembrane creep test data, the well-known creep factor model of geosynthetic materials and three-parameter creep model are given and the prediction results and experimental results are compared, and empirical model which is suitable for geomembranes is established.4. Investigation on identification theory of geomembranes constitutive model based on genetic arithmetic and overlay modelCompared with traditional optimization methods, genetic algorithm has a more efficient adaptive search function in analysis of geotechnical non-linear displacement. Based on the research of geomembrane constitutive identification method and the research of cascading model and genetic algorithm, the general form and parameter identification method of cascading theory was given and some useful conclusions were got by comparing test results and identification results.