Geosynthetic Reinforcement of Sand-Mat Layer above Soft Ground.

Jong-Beom Park,Daehyeon Kim,Hyun-Soo Park

doi:10.3390/ma6115314

Abstract

In order to improve the bearing capacity of soft ground for the purpose of getting trafficability of construction vehicles, the reinforcement of geosynthetics for sand-mat layers on soft ground has often been used. As the strength of the geosynthetics increases, and the sand-mat system becomes stronger, the bearing capacity of sand-mat systems will be increased. The depths of geosynthetics, reinforced in sand-mat layers, were varied with respect to the width of footing. The tensile strengths of geosynthetics were also varied to evaluate the effect of reinforcement on the bearing capacity of soft ground. The dispersion angles, with varying sand-mat thicknesses, were also determined in consideration of the tensile strength of geosynthetics and the depths of reinforcement installations. The bearing capacity ratios, with the variation of footing width and reinforced embedment depth, were determined for the geosynthetics-only, reinforced soft ground, 1-layer sand-mat system and 2-layer sand-mat system against the non-reinforced soft ground. From the test results of various models, a principle that better explains the concept of geosynthetic reinforcement has been found. On the basis of this principle, a new bearing capacity equation for practical use in the design of geosynthetically reinforced soft ground has been proposed by modifying Yamanouchi’s equation.

Highlights

There has been a great deal of progress in the research on the bearing capacity of sand-mats with1-layer structures at the time of designing the sand-mat method, which is the most common method applied to surface layer texturing for soft ground far
If geosynthetics and a sand layer are laid at the upper part of the soft ground, the form of failure becomes significantly different, which shows the trend of continuous increase in bearing capacity against settlement
● The result of calculation of bearing capacities based on the proposed new equation shows large differences compared with the calculation based on Yamanouchi's equation, and the bearing capacities of 1-layer structured sand-mat systems and 2-layer structured sand-mat systems tend to show big differences depending on load dispersion angle

Summary

Introduction

There has been a great deal of progress in the research on the bearing capacity of sand-mats with1-layer structures at the time of designing the sand-mat method, which is the most common method applied to surface layer texturing for soft ground far. Measured the effects of synthetic geotextiles to improve the bearing capacity of soft clay ground, using small-scale laboratory model footing tests. They claimed that an important role of bearing capacity was to increase bending rigidity, based on the confining effect of geotextiles by sand particles. Shin et al [4] carried out a field load test of geogrid-reinforced ground for the reclamation site of Incheon Airport. They reported that the size of the angle for load dispersion (α) d was reduced, depending on the increase of the applied load by unit area of loading plate, while the size of the angle for load dispersion (α) was increased as the number of layers of reinforcement was increased

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