In most conventional applications, geosynthetics are exposed to highest mechanical stress during installation. A series of laboratory simulation test for installation damage of geomembrane (GM) was carried out at different loading cycles on HDPE GMs where ISO 10722:2007 was used as a guide. The tensile properties of the samples were tested. The result of the test is reported and it has been found that number of loading cycle has irregular influence on installation damage. It is known that the service life of a GM depends on the exposure conditions, which in a landfill may involve adverse chemical exposure, elevated operating temperatures, and potentially large physical stresses. New equipment was developed and the installation damaged GM samples were exposed to pH solutions under different stress at elevated temperature for hours. Tensile tests was performed to get the residual strength and analyzed. It has been noticed that as the applied stress on GM samples increases, residual tensile strength decreases and they showed higher tolerance to acidic condition than alkali condition.