Performance Of Reinforced Soil-retaining Wall On Soft Soil Foundation

Reinforced soil-retaining wall is a composite structure formed by three parts, respectively backfill soil, a number of reinforcements arranged in the soil and panels. Reinforced soil-retaining wall is used widely throughout the world with the advantages of low cost, simple construction, aesthetic appearance, undemanding foundation, strong deformation compatibility and good seismic performance. To the behaviour of geosynthetic reinforced soil walls constructed on rigid foundations both domestic and overseas experts have been carrying out a lot of tests and theoretical studies, and many current design criteria are partly based on these researches. However, by contrast, reinforced soil walls constructed on soft foundations have received very few attentions. In this field, theoretical researches obviously have been lagging behind the engineering application. Moreover, in the design specifications, it hasn’t taken the influence of soft soil foundation on the reinforced soil retaing wall into consideration as well. So, this paper will focus on reinforced soil retaining wall construted on soft soils and give a systematic research. The main contents of the study are as follows,A project case of reinforced soil retaining wall built on soft foundation is introduced briefly and then by applying a finite element analysis software Plaxis 8.5 to simulate it. By comparing results from FE analysis with the reported observations, it proves that finite element method of simulating actual problems is feasible.The deformation characteristics, mechanical properties of reinforced retaining walls, and the regularity of distribution in reinforcements’strains&tensile forces are analyzed in details. Based on these analyses, it will help do a more further and systematic study on the key factors to the behavior of reinforced soil retaining wall, covering reinforcement spacing, length and stiffness of reinforcements, strength and stiffness of backfill soil, and interface strength etc.The paper analyses the changes of the deformation characteristics and mechanical properties under the consolidation settlement of soft foundation and the effect of construction process on the performance of retaining walls. Here it also thoroughly studies the influences on upper retaining walls coming from soft soil parameters such as strength, stiffness, boundary value and the location of soft soil layer.By comparing safety factor calculated separately by the limit equilibrium method and the finite element method, it discusses the stability of reinforced retaining walls on soft foundation. At the same time, the components of reinforced retaining wall such as backfill, reinforcement and interface have an effect on its stability; this is also studied in this paper.By applying the probability calculation method, it can do a reliability analysis on the stability of reinforced soil retaining walls on soft foundation. And then by Geo-Slope software, it gets a failure probability and a reliability index which can be used to evaluate the stability or risk level of the slope quantitatively.The paper summarized the primary conclusions from the study, as well as point out the shortcomings and the future work.