Analysis of Earth Retaining Walls Reinforced by Metallic Strip or Geogrid

Abstract

Earth retaining wall is a structure used for keeping and maintaining two different ground elevations. In application, sometime the earth retaining walls will combine with reinforcement element to increase the safety factor and any other reasons.Metallic strip and geogrid reinforcement which utilize friction between the fill material and reinforcement elements is one of the common applied. There are passive and active pressures in earth retaining wall analysis, whichare influenced bythe anchorage length. The analysis will compare the influence of passive pressure to its anchorage length. Moreover, the safety factor of the metallic strip and geogrid reinforcement will be compared with computer software. Since no specific element of metallic strip, the analysis will be conducted through an approach of geogrid and plate element. Passive force calculation on earth fill in the front of the retaining wall with a height of 12 m could shorten the anchorage length by 0.25% for 0.6 m depth; 0.38% for 0.7m depth; and 0.88% for 1.5 m depth. Hence, passive force does not have to be calculated as it gives a little difference in anchorage length compared to anchorage length calculation which ignores the passive force. Geogrid and plate elements used for modelling metallic strip in PLAXIS gives safety factor with a difference of 0.7%-3.4% and share similar landslide pattern. Therefore, metallic strip can be modelled using an approach of geogrid and plate element. The case study project shows the safety factor of geogrid and metallic strip reinforcement is minimum 1.2. However, geogrid reinforcement has 13.7%-31.4% higher safety factor compared to metallic strip.