Parameter Optimization of Geogrid-Reinforced Foundations Based on Model Experiments and Numerical Simulations

Guolong Zhang,Yuyou Yang,Fei Su

doi:10.3390/app9173592

Abstract

Dynamic compaction and geogrid reinforcement are two of the well-known methods used in improving the mechanical properties of fill foundations. In order to investigate their mutual restriction when used simultaneously and optimize the design parameters, model experiments and numerical simulations were conducted. First, three factors (embedded ratio of reinforced geogrid, number of reinforced layers and interval of reinforced layers) that are related to performance of reinforced geogrid were analyzed by model experiments with dynamic compaction. Then, orthogonal analysis was performed by numerical simulation (dynamic analysis in FLAC3D) to take into account five different elastic moduli and internal angle of friction along with the aforementioned three factors. Last, range analysis and variance analysis were performed on the orthogonal results to optimize the five factors by the calculated indicators. Additionally, linear regression analysis reflecting the relationships between five factors and four indicators was presented. The displacement field, compaction effect, earth pressure, and geogrid deformation of the reinforced soil under different combinations of the five factors were explored. Experiment and simulation results provide practical guides to the design of reinforced methods and a reference for the stability and deformation of other earth reinforcement projects under dynamic loads.

Highlights

With the rapid development of infrastructure in recent years, a considerable number of large fill projects have been initiated in China, many of which involve foundation construction in the southwestern regions, where coarse-grained soil is dominant
Based on the principle of similitude ratio, the test data are converted into prototype data so that it can better correspond with the field conditions
Various factors potentially affect the influence of geogrid reinforcement such as effective reinforced depth, crater depth, lateral displacement, lateral earth pressure, and deflection of first reinforced geogrid

Summary

Introduction

With the rapid development of infrastructure in recent years, a considerable number of large fill projects have been initiated in China, many of which involve foundation construction in the southwestern regions, where coarse-grained soil is dominant. The most popular approaches for treating fill foundation include dynamic compaction and geogrid reinforcement. Many researchers have investigated the densification effects of DC on sandy soils (Feng et al, 2013; Michalowski et al., 2012), deposits (Lukas, 1980; Feng et al, 2011), collapsible soils (Rollins et al, 2010), red clay soil (Liu et al, 2008), and solid waste (Zekkos et al, 2013) [4,5,6,7,8,9,10]. Based on a great deal of information from compaction tests on dry sand materials, researchers analyzed the relationship between the compacting energy and the compacting effect and indicated that the influence of the construction process is determined by the choice of equipment and relevant factors, including tamper weight, shape, dropping height, and interval between tamping point (Poran and Rodriguez, 1992) [11]. Many tests indicated that there are many laws affecting soil reconsolidation and deformation, such as impact

Methods

Results

Conclusion