A series of model tests were conducted to investigate the effects of installing reinforcement layer above the pipe on the deformation characteristics of PVC pipes. The number of reinforcement layers, types of reinforcements, and burial depths of the pipe were varied in a number of tests. The test results showed a significant increase in bearing capacities when reinforcements were introduced, while the reduced settlement caused by improved bearing capacities with buried reinforcements had little effect on resistance against pipe deflection. When the burial depth of flexible pipe was shallower than the width of the loading area, the effectiveness of reinforcements in reducing pipe deflection increased as the load became larger.

Soil is weak in tension but strong in compression. The resistance to tensile deformation of soil is given by the tensile force of the reinforcement in the reinforced soil, and the tensile force of the reinforcement is generated by the frictional force at the soil-reinforcement interface. When the soil-reinforcement is effectively interacted by the compaction, the deformation of the soil becomes equal to the tensile deformation of the reinforcement material, which means that the soil is bound to the tensile force of the reinforcement material and thus has a great resistance to the tensile deformation. Therefore, compaction is one of the major parameters affecting the behavior of the mechanically stabilized earth (MSE) wall. In this study, a series of numerical analyses was performed to investigate the compaction effect on the behavior of the MSE walls. The results showed that the horizontal displacement of the MSE wall significantly increased during the construction and decreased because of surcharge load application after the construction. In addition, the strains of reinforcement increased significantly during the construction and decreased slightly because of surcharge load application after the construction. Therefore, it is important to consider the compaction loads when modeling the MSE walls, so that the lateral displacement at wall facing will not be underestimated during construction and will not be overestimated because of surcharge load application after the construction.

A geotextile tube is a type of geocontainer typically filled with sandy slurries and fine-grained dredged sediments. Its performance in strength, dewatering, fine-particle retention, and stacked stability has been studied extensively. However, very little is understood about the shape-deformation behavior of geotextile tubes. In this paper, slurry-settlement, constant head permeability, and seepage-force tests were conducted to determine the geocontainers’ geotechnical design parameters. The characteristics of the dredged fill material determined from the slurry-settlement, constant head permeability, and seepage-force tests are presented. Large-scale tests on model geotextile tubes were also conducted. A large-scale apparatus for geotextile tube–filling test simulation is introduced. The apparatus consists of a slurry mixing station, a pumping and delivery station, a geotextile tube–filling station, and a data station. The results of the model tests conducted on a transparent geobag (undrained co...

The Saemangeum seawall, located on the western coast of Korea, is 33.8 km long and is known as the longest embankment in the world. The Saemangeum project is underway for road, railway, and port constructions for internal development. In the Saemangeum area, suitable granular soil for embankment material is difficult to obtain. However, silty clay is widely distributed. In this study, a series of model-bearing capacity tests were conducted as a basic study for using clayey soils as embankment materials. The model bearing capacity tests were carried out using a standard metal mold and a customized metal box. The test results showed that clayey soil, with normal moisture content (NMC), exhibited a large deformation and low bearing capacity. However, when the clay was well-compacted, with optimum moisture content (OMC), it exhibited a higher bearing capacity than dense sand. In addition, when crushed gravel and composite geotextiles were placed in the clayey soil with NMC, the bearing capacity was higher than that of dense sand. From the viewpoint of the bearing capacity, it is considered that clayey soil can be used as an embankment material when clay, crushed gravel, and composite geotextiles are properly combined.