This paper firstly describes the current legal requirements on hydraulic barriers for landfills in Japan, and the Geosynthetics barriers and its configuration that have been used in the coastal landfill sites. Then, two case histories are presented. One is a construction project of coastal landfill on permeable ground in the Inland Sea as the first case under the current legal requirements. In the project the double geomembrane Geosynthetics barrier system was installed on both side and bottom of the landfill. The highlights of analysis, design and construction methods conducted in the project are presented. The other is the development of new type clay barrier for coastal landfill that improves toughness of the brittle cement treated clay by inclusion of fibrous materials while keeping sufficient impermeability. The mechanical and hydraulic properties were examined in laboratory tests. Concept of mixing design was further clarified by plant mixing tests, and the performance of HCB in a practical use was verified through an actual experience in the field.

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Pipe Jacket is woven by circular loom then it is seem less woven geotextile. Pipe Jacket is made of polyester fiber on machine direction, and polyester monofilament on cross-machine direction. Characteristics of this pipe are high tensile strength, high strength of pressure and high ability of drainage. Drainage ability was examined comparing with conventional way such as poly vinyl chloride a pipe which has small holes. As a result Pipe Jacket was 4-10 times many on drainage and 2 times many on filtration. 30m length Pipe Jacket was constructed on the slope at landslide aria. The ability of drainage of Pipe Jacket was confirmed on this site.

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Few research about puncture resistance of geotextiles applied at waste disposal sites has been reported. We haveconducted the puncture tests of some geotextiles such as waterproof geomembranes and nonwoven fabrics, andtheir puncture resistance was characterized. Especially, we found experimentally that the breaking performance ofgeomembrane was improved by sandwiching two nonwoven fabrics.
We also showed the new experimental and analytical methodologies about puncture test.

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Landfill cap covers that simultaneously suppresses water infiltration to the waste and promotes rapid gas permeation is demanded. We have developed geocomposites (GCs) consisting of a porous sheet, which exhibits waterproof and gas permeability, and nonwovens to protect a porous sheet and investigated the characteristics of GC for application as a landfill cap cover. In this study, applicability of GC to the slope of landfill cap cover was evaluated in field test. Results show that the test slope remained stable even though water contents of the cover soil transiently increased because of the precipitation and applicability of GC as landfill cap cover on the slope was demonstrated. In addition, we proposed the outline of design on the sloping landfill cap cover that GC is installed.

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The quality of water in a closed water body such as lakes and ponds has been getting worse in recent times. Several measures such as dredging methods have been taken against eutrophication. However, some problems are encountered on the low-water depth lakes. This study conducted fundamental study on cover material to inhibit nutrients elution from bottom sediment using solid waste and geosynthetics. By using this cover material, we can try easily water purification. This study investigated the effect of inhibition of nutrient elution from bottom sediment by cover material by water tank test under the condition similar to actual environment. The results of water tank test indicated that the cover material can inhibit turbidity. This finding is attributable to the fact that cover material of bottom sediment hinders the diffusion of nutrients from bottom sediment to water and prevents further increase of suspended solids.

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The objective in this study is to consider a suitable geotextile filter to be hard to arise a clogging Chiba loam obtained from a field site and in-situ hydraulic gradient. This study was performed to focusing attention on a change of coefficient of permeability normal to plane on a kind of geotextile filter and ground condition. A series of constant head permeability test was performed to investigate a cross-plane flow performance of geotextile filter and clogging characteristic. Based on test results, it was found that the suitable geotextile filters to be hard to arise a clogging for Chiba loam are the GTXS-40 and GTXN-37.

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To evaluate the permeability of the ground reinforced with Geogrid, two types of tests; a triaxial permeability test and a large scale-pit test were conducted. The former is an element test which is not allowed to move soil particles under different conditions. The latter is a model test which is not allowed to move soil particles under different conditions. The results of the former test concluded that there is no difference between specimen reinforced with Geogrid and specimen unreinforced Geogrid when their compaction degrees were enough. The results of the latter test concluded that Geogrid restricts the movement of soil particles.

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Vacuum dewatering method with geotextile tube, which applied vacuum consolidation to Geotextile tube dehydration method, was previously proposed. The proposed method is the technology for improving the performance of dewatering and volume reduction by providing a drainage layer in a geosynthetics bag and applying vacuum pressure in the drainage layer. In this paper, the proposed method was developed by locating a plastic board drain on the surface of the bottom of a geotextile tube. The effectiveness was discussed based on test results using clay with high water content like muddy water. As a result, it was shown that high vacuum pressure is kept and it can dewater in a short time. Furthermore, based on study of test results, some construction methods were proposed.

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The geogrid-reinforced soil structures play important roles in the reinforcement applications since 1980s. Generally in design of the geogrid-reinforced soil structures, the soil-geogrid interaction behavior is not directly considered. Instead, the interaction strength is represented by the consolidation drained strength of soil commonly. However, neglecting the effect of compaction and suction on enhancing soil strength in design possess great conservativeness, leading to the waste in engineering practice. Moreover, along with providing appropriate drainage, the effect of water presence on stability of reinforced soil structures is not specially considered in design. As a result, reinforced soil structures have the possibility to failure caused by rainfall even totally following design code. Therefore, a trend considering the compaction effect and suction influence on the soil structure's behavior has arisen. For such trend, soil-geogrid interaction behavior need to be carefully investigated paying attention to the infiltration to avoid failure due to the rainfall. In this research, improved pullout tests capable of simulating in-suit rainfall infiltration are conducted considering the influence of rainfall infiltration and compaction. In order to survey the infiltration effect on interaction behavior, the pullout behavior of infiltrated soil samples are compared with the pullout behaviors of dry soil sample and soil sample with optimum water content. And the soil samples in pullout test are prepared in different degree of compaction paying attention to the compaction effect. The test results demonstrate that the infiltration dramatically reduces the pullout strength of soil-geogrid interaction. Meanwhile, the compaction could not mitigate the harm of infiltration on the pullout strength although it is able to enhance the peak pullout strength obviously.

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The soil-geogrid interaction process was analyzed by the Particle Image Velocimetry furthermore spatial discretization scheme in finite element method to understand about the dilatancy mechanism and shear strain distribution during unloading-reloading process. In this test the geogrid was pushed back and forth at three stages of pullout test: before peak, at peak and at residual part to simulate the seismic activities. Results showed that the shear strain concentrated in front of transverse ribs and upper apart of pullout box. The dilative behavior appears in front of transverse ribs and contractive behavior exits at behind of these bars. The alternative soil dilatancy-contraction distribution in between the two transverse ribs can be seen throughout the length of geogrid.

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Reinforcement, such as strips, woven-geotextiles and geogrids, is used to tensile-reinforce the backfill of soil structures in recent civil engineering applications. However, the use of geo-cells as tensile reinforcement has been quite limited, but geo-cells have been often used to restrain the foundation ground from horizontal spreading when subjected to vertical load by, for example, embankment, light-weight houses and traffic. Geo-cells have such advantages as that large-particles can be contained inside the cells and respective cells have a large anchorage capacity when pull laterally. On the other hand, conventional type geo-cells are not designed to have a high global stiffness when pull laterally. To examine whether geocells can be function as tensile reinforcing when used to reinforce the backfill of, for example, retaining walls and foundations. A series of laboratory tests were performed to evaluate the pull-out resistance of small-scaled models of geo-cell having different heights and lengths under two different normal pressures of 1 kPa and 30 kPa at the crest of the backfill in which the geo-cell models were arranged. Significant effects of the length of geo-cell layer on the pullout resistance were found, while the effects of the height of geo-cell were insignificant. The progress deformation of geo-cell in the direction of pull-out due to a rather low global stiffness was confirmed. The test results indicate that the pullout resistance of geo-cell can increase significantly by changing the structure of geo-cells to that the global tensile stiffness largely increases. The test results also suggested that geo-cells may function as tensile reinforcement particularly used with gravelly soil.

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In the geosynthetics engineering field, long-term creep deformation of polymeric geogrids has been evaluated by performing of creep test under a constant temperature. However, it is difficult to directly evaluate the long-term creep deformation of polymeric geogrids corresponding to the design life time by using this method. In the present study, a series of accelerated creep tests based on time-temperature superposition principle was performed to evaluate long-term creep deformation of various types of polymeric geogrids. In total four types of geogrids made by polypropylene (PP), high-dense polyethylene (HDPE), polyester (PET) and vinylon were used. As a result of the present study, it was confirmed that accelerated creep test can evaluate the long-term creep deformation of various types of polymeric geogrids.

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Thrust force is generated at pipeline bends due to internal pressure. The thrust forces can induce joint separations of the pipelines. In Case of high internal pressure, effective methods for thrust restraint are required.
Methods for thrust restraint using liquefied stabilized soil reinforced with geosynthetics are proposed in this paper. We expect that the liquefied stabilized soil is an effective backfill material against the thrust force. In addition, the geosynthetics contributes to restrain the failure of the liquefied stabilized soil.
In this paper, bending tests of the liquefied stabilized soil and image analyses by PIV(Particle Image Velocimetry) in order to verify the effect of the proposed methods for thrust restraint are discussed.

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At Hanoi city in Vietnam, the subway system will be planned for the purpose of modernizing a city's transportation network. In this study, a series of Oedometer tests and Consolidated - Undrained triaxial compression (CUB) tests were performed on Liquefied Stabilized Soil (LSS) based on Hanoi clay and LSS mixed with fibered material. The CUB test results of LSS based on Hanoi clay and NSF-CLAY were compared, and the influence of adding fibered material on effect of reinforcement were discussed. It was found that consolidation yield stress increases as increasing paper content and ductile property of LSS was improved by means of the effect of reinforcement on fibered material. Thus, It was found that the inhibiting effect of settlement increases.

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In order to evaluate the effects of geogrids in improving the compactibility of poorly compactible granular materials made from recycled glass bottles, compaction tests were conducted. They revealed that geogrid was effective in improving the compactibility. Moreover, in order to evaluate the effects of geogrids in improving the deformation and strength properties, triaxial tests were conducted on this material compacted with geogrids. They revealed that residual strain after cyclic loading could be reduced by using geogrids. However, small strain stiffness during cyclic loading did not change significantly. On the other hand, the peak strength under monotonic loading could be improved by using geogrids.

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Performance evaluation of railway retaining walls is conventionally conducted by visual inspection. This is because there is no quantified evaluation of the railway retaining walls in the present. Therefore, to evaluate the performance of the retaining walls, the performance evaluation test by using a small shaking devise was proposed. In this method, the small shaking device was set on the top of the retaining wall and measure a natural frequency of the wall. By using the field test result, a numerical back analysis was conducted to calculate a coefficient of subgrade reaction of sound and unsound walls. The possibility of the quantified evaluation of the reinforced retaining wall was discussed in this paper.

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Several The Noto Hanto Earthquake with magnitude of 6.9 occurred around 40km of the Noto Peninsula Oki on March 25, 2007. The Noto Hanto Earthquake caused enormous damages to road, airport and railway facilities, as well as the embankment and liquefaction of ground etc. Near the Noto toll road, the acceleration of earthquake was estimated 600~900gal. At the section of Noto toll road from IC-Tokudaotsu to IC-Anamizu eleven locations were found to occur large-scale collapse of embankment. For the collapsed embankment, the early restoration is developed by the temporary restoration, and then the long-term restoration is employed. The long-term restoration is performed based on the reinforcement method using the geotextile with excellent earthquake resistance. For one of the eleven large-scale collapsed locations, since the collapse of 250m extension and 25m high is large-scale, the embankment was restored by the reinforced soil with sensors to estimate the healthiness in the future. This paper reports the dynamic observation of construction of restoration and the monitored results after construction.

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This paper describes a reinforced earth wall deformed after the Iwate-Miyagi Nairiku Earthquake in 2008. Outer wall surface displaced about 170 mm to the front and some of the concrete panels were damaged. The reinforced earth wall is characterized as a double-walled structure. The space between the front concrete panel wall and inner backfill reinforced by geogrid is filled with deformation absorption layer of crushed stones. Because there was no further wall displacement in about 10 months after the earthquake, the reinforced earth wall was considered to be in acceptably stable state. Only the damaged concrete panels were replaced. The backfill reinforced by geogrid was inspected by means of 2-D surface-wave exploration technique and found to be in acceptable conditions corresponding to the Standard Penetration blow counts ranging from 21 to 34.

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For establishing a highly-performed road network against earthquakes, the seismic reinforcement of road embankments is very important. In this paper, a new design idea: "artificial base-ground structure" is proposed adding to the existing "crest reinforcing structure" to control sliding failure of road embankments. The effects of seismic reinforcing methods based on the above two design ideas and their combinations are calculated with use of the safety factor analysis based on seismic coefficient method, and the application of the "crest reinforcing method using geosynthetics" combining with the "artificial base-ground structure" considering Level-1 and Level-2 seismic motions is discussed and clarified.

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This paper covers analysis of the application of the geo-synthetics materials for the reinforcement technology of slope stability damaged by heavy rain fall is targeted. For this purpose, three parallel layers model which generate tensional force moving apart from the original slope is utilized to simulate qualitatively. This model helped to but approximately a sliding force generated by infiltration of water from surface of ground and rising of ground water from sliding plane. Evaluation of proper use case and efficiency level of geo-synthetics materials are performed on the results of analysis using the proposed model. Also the paper refers that the role of geo-synthetics is expanded to connect with various kind of small change of slope protection.

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The divided box bag method(D·BOX Method) is developed as a modern earth reinforcement method using "soil bags". The case studies of the construction of a road on a very soft ground(marshy place) by the D·BOX Method and the loading test on the D·BOX bags at the same marshy place by the road are presented. The D·BOX bags with crushed stones inside act as a permeable layer and promote the local consolidation and strengthening of the very soft soil just under the D·BOX bags in a few weeks. In addition, the D·BOX bags also act as an apparatus damping the traffic vibration, because the vibration energy is dissipated as the frictional heat energy between soil particles in the D·BOX bags. The case studies of the in-situ vibration tests using the D·BOX bags are also reported.

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In order to reduce deformation of ballasted tracks during large earthquakes, a new method to reinforce ballasted tracks with stacked geosynthetic bags that are filled with ballast was proposed. In this study, some performance tests of geosynthetic bags for railroad ballast are conducted. In triaxial test, geosynthetic bags filled with ballast revealed higher strength than ballast with no bag. In cut strength test that simulate real construction process, bags made of polyethylene revealed good performance. Its combination with polyarylate that is one of high strength fibers improved the performance further. In ultraviolet ray resistance test, geosynthetic bags made of polyethylene and polyarylate revealed less than 60% loss of pull strength at 5000h irradiation of super xenon weather meter that was equivalent to 10 year irradiation of sunlight, and the residual strength was high enough to satisfy the required value.

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Most of small earth fill dams had been built long before adopting the modern design. Therefore, there are too many inadequate small earth dams by a current standard design. In view of this circumstance, we have to make a strategy against disaster risk by earthquakes and heavy rainfalls, and need a new type of rehabilitation technology for disaster protection and/or mitigation. In this study, in order to increase stability of a small earth dam against seismic force and overtopping, two types of full scale shaking model tests with soil bag system were conducted in stepwise shaking with regular acc. wave. One is conventional type with stacked horizontal(δ=0°). The other is a proposed type with stacked inclined(δ=18°), like a masonry wall. As a result, slippage between soil bag interfaces easily occurred at max. acc. of 500gal in the horizontal stacking case. On the other hand, in the inclined case, slippage between soil bag interfaces hardly occurred even at 1,000 gal. It was found that just changing stacked direction could improve a seismic stability of soil bag slope.

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Thrust forces are generated at bend pipes due to internal water pressures. Generally concrete blocks are installed at bends to resist thrust forces. However, it has been reported that concrete blocks were one of the weak spots of the pipe system during earthquake. To improve the pipe system during earthquake, we previously proposed to replace concrete blocks with a lightweight thrust restraint technique using geogrids. In this study, the field test on the lightweight thrust restraint for buried bend pipe was carried out in order to examine the behavior of the bend pipe in the field. From the test results, it was found that the steel bend pipe with the proposed method performed satisfactorily under internal water pressures.

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Liquefied stabilized soil has been used as a backfill material of pipelines recently. Methods for thrust restraint using liquefied stabilized soil are proposed in this paper. We expect that the liquefied stabilized soil is effective backfill material against the thrust force. Model pit tests using a model pipe with a diameter of 260 mm were carried out in order to examine the effect of the liquefied stabilized soil for the thrust restraint of the buried bend. The liquefied stabilized soil was applied to the passive area of the model pipe and dry silica sand was used as backfill material. The model pipe was laterally loaded at 1 mm/min after backfilling to simulate the thrust force. The lateral resistance and the lateral displacement of the model pipe were both measured.
The results showed that the lateral resistance in case using the reinforcement material was increased. Furthermore,it was verified that the types of reinforcement materials influenced the lateral resistance.

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In recent years, cement-mixed gravel, crushed stone for mechanical stabilization with a little volume of cement, is often applied to soil structures allowing a limited degree of deformation. From laboratory tests or on-site tests, it was revealed that this material has sufficient strength and deformation characteristics against compression. Furthermore, this material exhibited a high resistance characteristic against bending moment by reinforcing this material with geogird. In this study, therefore, the applicability of this composite material as a bending member to the construction of embankment on liquefiable ground or soft ground was evaluated and a few typical case examples where the proposed method was applied for the construction of railway embankment were presented.

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This paper discusses on geosynthetic-erosion control method for levees. This method is an intimate river work for natural conservation. In this study, 16m-flume model tests were conducted to investigate the optimum shape of geocomposite for erosion control. This paper reports the laboratory model test results and proposed new evaluation methods for erosion control effects of geo-composite.

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This paper proposes a new technique, which uses the high energy absorption net, to upgrade the performance of existing rockfall protection fence. The high energy absorption net is set at the mountain side of the existing rockfall protection fence in this technique. In order to confirm the applicability of the proposed technique, field tests and numerical analyses are carried out. This paper describes the detail of the proposed technique and the results of the field tests and the numerical analyses as well as the effectiveness of the high energy absorption net to upgrade the performance of the existing rockfall protection fence.

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Laboratory large-scale model (length: 1.50m, width: ~0.62m, height: 0.85m) tests and finite element analyses (FEA) were conducted to investigate the deformation characteristics of soft clayey ground under the combination of vacuum pressure and surcharge load. Both the model test and FEA results indicate that the combination of vacuum pressure with surcharge load can reduce the lateral displacement of the model ground. The outward lateral displacement increases with the increase of the loading rate (LR) of surcharge load and the ratio of surcharge load to vacuum pressure (RL). The results also indicate that by adjusting LR and RL, the lateral displacement of the ground can be minimized.

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In this study, we carry out the full-scale dynamic cyclic loading experiments of the ground reinforced by using geocell and geotexitles. Then we discuss the stability of the reinforced ground. The experiment grounds reinforced by some methods are constructed continuously in the site. The cyclic loading is given by the load vehicle (a heavy vehicle: 20 ton dump track) on the ground. As the results of experiments, the stability of each reinforcement method is compared relatively.

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“Geosynthetic-reinforced soil (GRS) Integral Bridge” comprises “Integral Bridge” and “Bridge with GRS Retaining Walls as Abutments”, improving the structural and soil components, respectively, of conventional type bridges. GRS Integral Bridge is characterised by; 1) the use of a continuous girder connected to the top of RC facing, without using bearings, which reduces the cost for construction and maintenance; 2) reinforcing the backfill with geosynthetic reinforcement (e.g., a geogrid) connected to the back of the facing; and 3) the staged construction of a full-height rigid facing by casting-in-place concrete on the wrapped-around wall face of the reinforced backfill after the deformation of the backfill and supporting ground by the backfill weight is over, which makes possible high compaction of the backfill immediately behind the facing and prevents the damage to the connection between the reinforcement and the facing while making the structure of the facing simple and the need for pile foundations lighter. As the facing is a continuous beam supported at many levels with a small vertical span (i.e., 30 cm), damage by annual cyclic thermal deformation of the girder and seismic load is minimised.

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The geosynthetic reinforced retaining wall has been known as a highly cost-effective method for retaining wall. A new type bridge, geosynthetic-reinforced soil (GRS) integral bridge which combines integral bridge with geosynthetic reinforced backfill has been proposed. We performed a series of static loading tests and shaking table tests with small models to evaluate the stability of GRS integral bridge. The active failure and increment of earth pressure of backfill due to annual expansion and contraction of the deck is solved by geosynthetic-reinforcing of backfill. The seismic failure mechanism of GRS integral bridge is also revealed by shaking table tests. We performed another series of tests to consider the effect of structural condition to the stability of GRS integral bridge. The model test results and consideration of effect of structural condition on GRS integral bridge are summarised.

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For practical applications, full-scale test integral geosynthetic-reinforced soil (GRS) bridge, having a width of 3m, height of 5.55m, length of about 14.75m, was constructed. Aiming to measure variations in temperature and variations in the cyclic loading test on bridge girder, field observation has started. Measurement items are, stress of Geosynthetics, displacement between the end of bridge girder and backfill, vertical earth pressure on the bottom of the footing, horizontal earth pressure on the abutment, inclination of abutment, temperatures and reinforcing bar stress. From a 4 months measurement results, in response to seasonal variations in temperature, which also reacts the bridge. But, its variation is quite small. The integral GRS bridge, which length is around 15m, found to be stable enough to seasonal variations in temperature.

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For the practical use of the GRS integral bridge where making to high performance was confirmed by the model experiment etc, the examination bridge was constructed, and field observation is continued now. When practical use develops, it is not established now though the establishment of the design method becomes necessary indispensable. However, it is thought that the reinforced soil method and the design method of a rigid frame viaduct can be applied from the mechanism of this structural behavior. Then, it designed to the bridge based on these design methods, and the feature concerning the design was arranged in this examination.

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Because it has been proven that soil obtains a big strength and bearing capacity by completely rolling it like “soil bag”, a new reinforcement method of wrapping soil with geotextile is presented. The method of calculating the tension in the geotextile is shown. Moreover, the loading tests on the reinforced test embankment are performed. The test embankment is 1.8m in height, and 1.5m in upper width. The load on the test embankment is increased as much as 300kN/m², and the geotextile strain, the deformation of the wall face and the earth pressure are measured. As a result, it is confirmed that the method of calculating the tension is valid and the deformation of the wall face becomes small by rolling soil.

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In general, in the case of private building site, concrete retaining walls are used for slope repair work. However, there are problems in the construction of retaining walls such as the removing of a large amount of soils and the time for curing of concrete. Moreover, there are examples that the appearance or the cost takes priority over the slope stability unlike public construction. Geocell-reinforced method has distinctive features such as the possibility of tree planting and shortening of construction time by simple construction. In this paper, we report a construction example of geocell-reinforced soil wall in private building site where appearance is valued.

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Geosynthetics such as geogrid or geotextile are usually applied in practical field for reducing displacement of soil structures and earth pressure acting on structures and increasing bearing capacity of foundations. The deformation and failure mechanism of the ground reinforced with geosynthetics is, however, not fully clarified. In the present study, mechanical behaviour of geosynthetic-reinforced soil retaining wall is investigated and the reinforcing mechanism by geosynthetics is discussed through two-dimensional laboratory model tests and their corresponding finite element simulations. In the model tests, mass of aluminum rods is used as ground which shows mechanical characteristics similar to that of medium dense sandy soil, and tracing paper having almost no bending stiffness is used as reinforcement material. The simulations are carried out using elastoplastic subloading t_ij model (Nakai and Hinokio, 2004). The model suitably can considers the influence of intermediate principal stress on the deformation and strength of soils, dependence of the direction of plastic flow on the stress paths, influence of density and/or confining pressure on the deformation and strength of soils. Several tests are carried out varying the arrangement, length and number of the geosynthetic-reinforcements. It is discussed that the effectiveness of geosyntheticreinforcements mainly depends on whether they increase both internal stability, which is local stability within the reinforced ground, and external stability, which is overall stability of the surrounding ground. The results obtained from the numerical analyses show qualitatively good agreement with the results of the model tests.

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Many reinforced earth walls using geotextile materials have been constructed in recent years. While the deformation of such earth walls due to frost heaving has been reported in cold regions, hardly any studies have been conducted concerning measures against the phenomenon. Accordingly, five types of full-size model were created with a focus on replacement, drainage and heat insulation to measure wall displacement, geotextile strain, soil temperature, embankment freezing conditions and other factors in winter conditions when embankment material freezes, and were compared with the standard method adopted to establish frost-heaving prevention measures for reinforced walls using geotextile materials. The results indicated the possibility of controlling deformation related to frost heaving by combining replacement and heat insulation measures.

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This paper proposes a new application of pile foundation to reinforced soil structure by geogrid, in order to improve horizontal resistance of the structure. In this study, the effectiveness of the application and dynamic interaction between pile and reinforced soil structure were confirmed from the results of a dynamic centrifuge model test (25G), and a design method of the reinforced soil structure with using piles (Piled Geo-wall) was proposed through the numerical simulation of the experiment by using two dimensional dynamic FEM analysis.

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We developed a new reinforced soil retaining wall system having a vertical layer which absorbs the deformation between facing material (concrete block) and reinforced fill, which is called ‘double wall structure’. This paper investigates the stability of the system during earthquake. Shaking table tests for 1/10 size model of the system, shows that the facing material and reinforced fill behave in one united body. The test result is simulated fairly well, by a numerical analysis based on Mohr-Coulomb yield criterion, a simple plastic flow rule and Newmark β method.

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Geosynthetic-reinforced soil walls have system redundant parallel structural system. In this case, failure of one structural component does not lead to collapse of structural system. This paper proposes new reliability analysis method for redundant geosynthetic-reinforced soil walls. Proposed analysis method is based on basic concept that failure of geosynthetic-reinforced soil wall is multiple. In this paper, outline of the analysis method is explained. Estimation method of partial safety factors with considering redundant structural system is also discussed.

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