The research work was started in 1989 in co-operation with Viatek-Yhtiot and Helsinki University of Technology. The main purpose of the project has been to develop a suitable practice for the use of synthetic reinforcing materials in Finnish conditions. The effect of cold climate and soft clay or peat subgrade which are significant in Finland have been emphasized. The investigations have included tensile tests, periodic loAtd tests and creep tests ( 1000 h) at different temperatures. Investigations of the soil-reinforcement interface friction and plate bearing tests in a big laboratory soil basin have also been performed. A part of the test results is still under treatment and the work will continue with full-scale trial structures. The results of the study of soil-reinforcement friction are presented in an other article by Forsman and Slunga (1994).