This Paper presents the result of a parametric study on the behavior of stiffened grid reinforced segmental wall resting on non-yielding foundation. The parametric study was conducted using the nonlinear finite element analysis. In the finite element analysis, the step by step construction of the wall such as backfill, block reinforcement, block/backfill and soil/reinforcement interfaces were carefully modeled. The mechanical behavior of stiffened grid reinforced segmental walls was then investigated based on the result of analysis with emphasis on the effect of reinforcement stiffness on the behavior of the wall. The results of analysis indicate that the horizontal wall displacement decrease; with increasing the reinforcement stiffness at a decreasing rate, and that the horizontal stress at the back of the reinforced soil block does not much vary with the reinforcement stiffness. It is also revealed that the calculated maximum vertical stress at the base of the reinforced soil block agrees well with that based on the Meyerhof distribution and that the reinforcement and the connection force are considerably smaller than what might be expected based on the current design assumptions. The implications of the findings from this study to current design approaches were discussed in detail.

The use of reinforced soil have been increased due to it's cost effectiveness, flexibility and so on. In this study, a full-scale reinforced soil with rigid facing were constructed to investigate the soil pressure variation of reinforcing system. The results of soil pressure during backfill construction are described. The influence of facing stiffness on soil pressure is addressed. The results show that lateral earth pressures on the wall are active state during backfill. It is obtained that the lateral soil pressure highly depends on the installation condition of pressure cell and construction condition. Long-term measurement will be followed to verify the design assumptions with respect to the distribution of lateral stress on the facing.

The last 30 years have been significant worldwide growth in the use of EPS as a lightweight fill material. A new construction method was introduced, which reduces earth pressure acting on culvert and conduit by placing a thin layer of EPS. This paper analyzes the compressible inclusion function of EPS and geogrid which can results in reduction of earth pressure by arching that is the behaviour of soil-structure system involving redistribution of soil stress around the structure. Field test was conducted to evaluate the reduction of vertical earth pressure using EPS and geogrid inclusion. Based on field test it is found that the magnitude of reduced vertical earth pressure was about 24~50% compared to conventional method.

The generally known vertical drain methods for improvement of soft ground are Sand Drain, Sand Compaction Pile, Plastic Drain Board, and Pack Drain. Recently, Plastic Drain Board method application in soft ground is widely used. In this case study, it is compared with each other vertical drain methods from the results of monitorning and test embankment. The results of the analysis and the study show that Plastic Drain Board method is relatively acceptable as vertical drain method.

In this study, slope stability analysis of LCRS(Leachate Collection Removel System) in waste landfill was peformed by large scale field test. Geocomat is new type of geocomposite product. Gecomat is a sort of Geocomposite product. It is composed of nonwoven geotextiles, woven geotextile, and geonet. Large scale field tests were performed on the slope of different two LCRSsections with static loading condition. One is LCRS section witch consist of GCL, HDPE and Geocomat, another is GCL, HDPE, and woven type geocomposite. The behavior of geosynthetics lined slope was monitored by incorporating instrumentation including vertical soil pressure meter, settlement plate, strain gauges, potential meter, displacement pin.. Based on the field monitoring, the Geocomat LCRS section is less sliding than the conventional geocomposite LCRS section.

Geotextiles are usually constructed as a protective layer of geomembranes in liner systems for the solid waste landfill. A protective layer and geomembrane are susceptible to mechanical damage by coarse grains in the overlying drainage layer. In this study, therefore, the strain behavior of geotextile protective layers was investigated using three different types of devices for developing punctiform loads. The results of the study showed that the rates of strain was different depend upon device types for functiform loads. Also, It was found that the increases in strain was approximately linear in range 20 to 6$0^{\circ}C$ , and pp-filament non-woven geotextiles yielded a better efficiency than pp-staple fiber non-woven geotextiles.

지금까지의 하천 사면보호공법은 돌망태, 사석, 호안블럭(Con'c Block), 재래형 섬유대공(Ordinary Fabric Form) 등을 주로 사용하여 왔다. 그러나, 이들 공법은 자연재료인 돌이나 사석 등이 이미 고갈되어 취득이 매우 어렵고, 콘크리트 제품은 인공구조물 일색의 보호공으로서 자연환경에 어울리지 않거나 인력을 이용한 고가의 공사비가 요구되므로 이를 개량하여 본 환경친화형 섬유대공을 개발하기에 이르렀다. 본 공법은 홍수나 수해로부터 토사제방의 침식 및 세굴방지는 물론 중간에 자연환경 적인 잔디나 조경식재를 하여 환경친화적 호안공을 형성하는 공법으로서 침식방지와 환경친화 효과를 동시에 만족시키기 공법이다.