Outline of the research work on the confining effect in soil-geogrid reinforced soil mass have been reported, which was done over 10 years in our group. Some research activities referred are first briefly introduced linked with our research direction. The existence of confining effect is then experimentally investigated, together with total reinforced effect. An evaluation method in which the reinforcing effect can be divided into tensile effect and confining effect is carefully discussed in relation to the dilatancy rate of reinforced soil mass. The mobilized confining effect is given by a function of the dilatancy rate and the internal friction angle at critical state. Further, the confining effect is introduced into a current calculation method for a factor of safety in steep slope reinforced embankment. It is found from the computed results that the total amount of reinforcement may be reduced by 5 to 20 (%). In addition, the influence of the vertical spacing of reinforcing layers on the confining effect is discussed to smoothly determine the confining effect from a practical point of view.

View full abstract

In recent years, cement-mixed gravel; crushed stone for mechanical stabilization with a few amount of cement, is often used for soil structure allowing a limited amount of deformation. In Japanese railway field, this material is now standardized for applying to approach block of bridge abutment of new Shinkansen line. From laboratory tests or on-site tests, it has revealed that this material shows sufficient strength and deformation characteristics equivalent to concrete. Therefore, cement-mixed gravel where geotextile is arranged for the tensile material is expected to be used as bending member, for examples, slab with ground-improvement piles as new-type countermeasure method for soft ground. As, the ratio of improvement is usually determined by the settlement of ground between piles, the ratio could be reduced by arranging this slab between soil structure and piles. The purpose of this paper is to conduct tri-axial tests, bending tests and shaking table tests experiments in order to realize this new countermeasure method.

View full abstract

The structure targeted with this study is SG-Wall method, and the shaking test results conducted with SG-Wall model is tried to interpret. The basic equations are derived from the concept of particle model and transfer load method that shown in detail in this paper. The shaking test s proves the efficiency of SG-Wall method on functioning as dynamic protection. Particle model is consist of three elements, steel sheet, cement treated soft soil block and connecting geo-synthetics material. Main point of this study is concerned with how to describe the effect of connecting force. As a result, the effect of connecting force on the dynamic stability of steel sheet is traced by the particle model that the stability condition becomes higher as the connecting force increases. However, this efficiency probably depends on the ratio of connecting force and weight of cement treated soil block. Maximum displacement occurred in the analysis tend to increase, if the ratio of a geosynthetics spring coefficient and the spring coefficient of the cement treated soil block exceeds more than a range. However, this tendency should be confirmed in future whether it is a general trend or not.

View full abstract

In this paper, a dynamic finite element method is proposed for earthquake analysis of the reinforced stabilized soil ground. The method is to solve an initial-boundary value problem by combining finite element method with particle discretization and soil-water coupling finite element method. Three cases of shaking table tests were simulated to verify the accuracy of proposed method. It is shown that the proposed method can simulate the observed behavior.

View full abstract

When the performance of road pavement deteriorates to specified management value due to traffic load, the road pavement is repaired or reconstructed. If the subgrade is softer, it needs the periodic repair for crack and faulting occurring with the settlement of subgrade. In the present study, we developed the "Packed-Foamed Cement Milk" which the lightweight foamed cement milk is injected in the bag made by geotextile. To reduce the traffic road acting on subgrade and to extend the repair cycle of road, we applied the Packed-Foamed Cement Milk to the current road on soft ground. This paper reports the design, evaluation and construction of road pavement by using Packed-Foamed Cement Milk.

View full abstract

A new technology for port construction using dredged material is proposed. The proposed technology (SG-Wall) is the combination of stabilization technique (S) of dredged material and geogrid (G) for quay wall (Wall). The target of the technology is both new construction of a quay wall and renewal of an existing quay walls for very large ships, which requires a large water depth in front of the quay.
The authors conducted pull-out test to examine the resistance between stabilized soil and geogrid. The authors also examined the seismic-retrofit feasibility of the proposed technique. Since the seismic resistance is the most important issue for Japanese port structures, behavior of the model under seismic shakings were experimentally examined using under water shake table. These test results show the high pull-out resistance of geogrid in stabilized-soil.

View full abstract

To investigate the deformation and strength characteristics of EPS-beads mixed sand, multiple series of laboratory triaxial compression tests were conducted under various values of the volume ratios of Toyoura sandand EPS-beads. In one of the test series, cement was not added, while in the other test series, cement was added.The small-strain properties of Young's modulus and Poisson's ratio were examined in detail under various stress conditions.

View full abstract

Although the air foamed lightweight soil method has become popular, it has some problems such as scatter of the strength and its durability. To overcome these problems, we try to mix the short fiber into the air foamed lightweight soil. This paper reports the results of laboratory and field model tests for the air foamed lightweight soil mixed with short fiber. In the laboratory test, we verify the effect of cement content and specific gravity for strength by mixing short fiber. In the field model test, the weight falls to top surface of the air foamed lightweight soil mixed with short fiber. We verify that the impact resistance is improved by mixing short fiber. Additionally, this paper repots the results of ongoing durability test for the air foamed lightweight soil mixed with short fiber.

View full abstract

A Liquefied Stabilized soil (LSS) is easy to occur a rittle failure as increased a strength due to an increasing of cement content. In the past study, it was found that a ductile performance of LSS after a peak was improved by adding a fibered material. In this study, a series of consolidated-undrained triaxial compression test (CUtest) were performed with a number of small unload/reload cycles in order to investigate the damage properties of LSS reinforced by fibered material. As a result, it is found that a reinforcement effect on the damage properties depends on the curing periods and fibered material content and confined pressure.

View full abstract

When volcanic-cohesive soils are disturbed, the soils are subject to lose its strength due to the high moisture content. Thus, a large quantity of stabilizer is generally required to improve the strength for using the soils as geomaterials. This paper describes the improvement effectiveness by short fiber reinforcement for Kuroboku soil. The cone penetration test, unconfined compression test and triaxial compression test were performed to investigate the strength properties. From the tests, it became clear that the short fiber reinforcement results in increase of unconfined compression strength, especially in residual strength, and trafficability, etc. This suggests that the amount of the stabilizer for volcaniccohesive soils can be reduced by mixing short fibers.

View full abstract

A new bridge system, called the GRS integral bridge, is proposed. The GRS integral bridge combines integrated girder and full-height rigid (FHR) facing with the backfill reinforced with geosynthetic-reinforcement layers that are connected to the back of the FHR facing constructed after the construction of the backfill. The top of the facing of an integral bridge displaces cyclically due to annual thermal expansion and contraction of the girder. Results from model tests revealed that the backfill may largely settle down and the earth pressure may largely increase by cyclic lateral displacements of the facing. When the bottom of the facing is hinge-supported, the earth pressure may increase largely, which may damage the facing. When the bottom of the facing is free, the active failure takes place easily in the backfill and the settlement in the backfill may become very large. It is shown that the GRS integral bridge is free from these problems.

View full abstract

An integral bridge, unifying a pair of RC facing and a continuous girder with unreinforced backfill, is known to cost-effective in construction and long-term maintenance. However, cyclic lateral displacements at the top of the facing caused by seasonal thermal expansion and contraction of the girder gradually increase settlements in the backfill and the earth pressure on the back of the facing, which may damage the facing and the head of piles if used and/or the facing bottoms are pushed out. As a new bridge type alleviating these problems, the GRS integral bridge, which combines an integral bridge and a pair of geosynthetic-reinforced soil (GRS) retaining walls having full-height rigid (FHR) facings, is proposed. To evaluate the performance of the conventional and new types of integral bridge, model tests were performed. Cyclic lateral displacements were applied at the top of the facing. The backfill was either unreinforced or reinforced with the reinforcement connected, or not connected, to the facing. The facing bottom was either hinge-supported allowing only rotation or not supported with a foundation with a small depth in the subsoil. When the backfill was not reinforced, large settlements in the backfill and a large earth pressure increase associated with a significant active failure in the backfill were observed. When the reinforcement was not connected to the facing, reinforcing the backfill did not alleviate these problems. These problems were fully alleviated when the reinforcement was connected to the facing even in the case where the facing bottom was not supported with a foundation.

View full abstract

A new bridge system comprising of a pair of geosynthetic-reinforced soil (GRS) retaining walls having full-height rigid facings that are unified with a girder, without using girder supports, is proposed. A series of 1g model loading tests of GRS Integral bridge were performed to evaluate the effects of the followings factors on the residual earth pressure and settlement of backfill by thermal cyclic horizontal displacements of the facing; a) connection between the reinforcement and the facing, b) displacement mode of the facing, and c) the amplitude of cyclic horizontal displacement of the facing. The backfill settlement by cyclic horizontal displacements cannot be effectively reduced by reinforcing the backfill when the reinforcement is not connected to the facing. Furthermore, an increase in the earth pressure becomes larger than when the backfill is not reinforced. These problems are amplified with an increase in the facing displacement. All these problems are solved by connecting the reinforcement to the facing.

View full abstract

We tried if the mechanical model which we propose could apply to the prediction of the deformation of a reinforced soil walls. As a result, the value calculated by the mechanical model agreed approximately with the deformation of the reinforced soil wall. As the next step, we examined the creep deformation of a reinforced soil wall by model experiment. The creep deformation of a reinforced soil wall was not proportional to earth pressure. The centre in the reinforced soil wall became a maximum. We also examined if the mechanical model which we propose could apply to the prediction of the creep deformation of a reinforced soil wall. Consequently, calculated values approximately agreed with the actual deformation of the reinforced soil wall. These results can be utilized for the design method of reinforced soil walls taking into account of deformation.

View full abstract

To achieve a high seismic stability of a newly proposed bridge type, called the GRS integral bridge, a high tensile resistance of reinforcement layers at the back of the facing is crucial. This resistance is the minimum of the connection strength between the reinforcement and the facing, the tensile rupture strength of reinforcement and the pull-out resistance of reinforcement. To evaluate the pull-out resistance of a rough phosphor bronze grid used in the model shaking table tests performed to evaluate the seismic stability of GRS bridge in comparison with those of other types of grid reinforcements including polymer grids, a series of pull-out tests were performed on these various types of reinforcement embedded in Toyoura sand under different vertical confining pressures. The pull-out resistance increases with an increase in: 1) the covering ratio and surface roughness of the longitudinal members of grid; and 2) the thickness of transversal members of grid. The peak resistance by the surface friction (factor 1) tends to be mobilized earlier than the passive pressure resistance (factor 2). The reinforcement used in the model shaking table tests has a resistance much lower than the largest one among those measured in the pull-out tests.

View full abstract

Pullout tests are effective to investigate the interaction mechanism along the interface in geogrid reinforced zone. Micro scale geogrid-soil interactions are one of the fundamental important issues in pullout test response as well as actual field behavior of earth reinforcement. Hence, the discrete element analysis is carried out for pullout test from a micro point of view. The discrete element model is conducted to investigate the pullout response paying attention to compaction effect linked with porosity. The specimen is investigated in different porosities in order to evaluate the influence of degree of compaction on the strength, linked with the interface microscopic behavior. And the dilatancy predicted in the model may also provide useful information on the increase of the interface shear resistance.

View full abstract

Reinforced soil with polymer reinforcement has been adopted in many fields. Geogrid reinforcement which is one of the polymer reinforcements is widely used for the reinforcement of embankments and retaining walls and its demand is significantly increasing. A performance test of the geogrid is necessary to evaluate its property before its installation. The most basic performance test is a tensile test at a constant strain rate. There are two types of clamps for this test, squeeze and roller types. Empirically, it is a well known fact that the tensile strength depends on the type of clamps. In this study, a series of tensile tests was conducted to evaluate the effect of clamp on the tensile strength of reinforcement at several facilities. In the result, the average of tensile strength with the roller type clamps became larger and its variability became smaller than those of the tensile strength with the squeeze type clamps.

View full abstract

The conventional selection of construction method is focused on construction cost with the allowable safety factor. However, performance of the structure should be evaluated with an adequate method. In this study, to evaluate the performance of earth slopes with and without reinforcement, a life cycle cost was calculated on the seismic condition. For the calculation of the life cycle cost, a limit state exceedance probability is essential, which was obtained by the first-order reliability method. Construction and reconstruction costs were estimated from the actual construction data. In the results, the life cycle cost of the earth slopes with reinforcement was lower than that of the earth slopes without reinforcement.

View full abstract

It is shifting from the design to the limit state design method that uses the allowable stress method in the organization that relates to the design of the structure now. When the performance is designed, the limit state design method is an effective design method. However, there is a limit in a quantitative evaluation of the physical properties of soil materials and the reinforcements that has potential variabilities. Then, to evaluate the performance of the structure that used the soil materials and the reinforcements quantitatively, the reliability analysis was executed in this research. Concretely, the limit state exceedance probability of a standard embankments was calculated by setting the performance rank of the embankments based on the railway standard, deciding the material physical properties and the embankments cross-section shape, and using FORM that was the approximation method. The result was arranged, and the limit state exceedance probability of the embankments in the static loading conditions was presented.

View full abstract

Landfill cap covers that suppress water infiltration to the waste and promote rapidly gas permeation at the same time is required. We have developed hybrid geosynthetics that consist of porous sheet and nonwoven geotextiles as landfill cap covers and their basic performances, i.e. waterproof, gas permeability, and construction durability, have been examined by laboratory and construction tests. In this study, field test was conducted to evaluate gas permeability of the hybrid geosynthetics installed in the underground by measuring the variations of volume fraction of oxygen gas with time while nitrogen gas was introduced to the soil layer under the hybrid geosynthetics. Laboratory tests were also made prior to the field test to verify the effect of water content of soil layer to the gas diffusivity. As the results, it was clarified that hybrid geosynthetics exhibit good characteristics on gas permeability even when installed in the underground.

View full abstract

The geomembrane such as TPO(PP), LLDPE and HDPE is widely used as barrier sheet in landfill. This barrier sheet used on side slope needs to be anchored by concrete. But the anchorage ability of concrete buried in the trench has not been clear till now. In this research, the pull-out tests for the geomembrane buried in the trench overlying the concrete were conducted. In the tests, two kinds of geomembranes were used. The size of sectional area was also changed. It was found that anchorage ability is almost proportional to size of section area, the geomembrane with lower rigidity seems to have higher anchorage ability and the strength of back wall in the trench may affect the ability.

View full abstract

The apparent opening size (O₉₅) of geotextile is a physical parameter closely related to the permeability property and/or amount of clogging of geotextile. In this study, since the apparent opening size is an important parameter, the apparent opening size test of geotextile on the wet method was performed and verified the adequacy of that test method. The apparent opening size of geotextile obtained from that test is discussed. Based on a series of constant head permeability test results on the various geomaterials carried out in the past, the effect of the apparent opening size on the permeability of the geotextile is also discussed.

View full abstract

Temperatures of 20-60 °C have been reported at landfill base. Such high temperatures have a potential to increase the leakage from lining system. Some researchers conducted column tests with the thermal gradient in order to investigate the effects of the thermal condition on the barrier performance of the lining system. They evaluated the desiccation and deterioration of geosynthetics, and the water content distribution of the dried base layer. However, there are few reports that the leakage increased by the thermal effects were quantitatively evaluated.
In this study, column tests with geosynthetic clay liner (GCL) were conducted using 20 °C or 60 °C sodium chloride solution as the permeant liquid. These column tests simulated an actual lining system, which consisted of GCL and base layer soil. By monitoring the temperature and water pressure head in the base layer and the leakage volume from the GCL, the barrier performance of the GCL was evaluated. The apparent hydraulic conductivity for 60 °C NaCl solution was 3.2 × 10^-7 cm / s, and was about seven times higher than that for 20 °C NaCl solution.

View full abstract

In this study, we conducted shaking table experiment and dynamic effective stress analysis using the program FLIP on gravity-type seawalls surrounding controlled waste disposal site founded on clay ground. In these experiment and analysis, the deformation of gravity-type seawalls and water proof sheets was evaluated. At this point, we used an earthquake motion to simulate the level 2 earthquake motion in a target harbor. In addition, to express the slide between water proof sheet and ground, static FEM analysis of water proof sheet and the surrounding ground was conducted with joint element method. This static analysis was conducted by inputting the displacements at the nodal points as the boundary conditions, giving by the dynamic analysis. As the results, dynamic behavior of seawalls, water proof sheets and the surrounding ground in this experiment was reproduced on the whole by these analyses.

View full abstract

In 2001, we developed the adhesive waterproof sheeting for open-cut tunnels, which is popular in construction of underground structures such as subway stations and railways. Recently we developed the new type of sheeting which has better adhesion performance compared with the previous one. The technical point of the improvement is changing the chemical components of the adhesive layer from ethylene vinyl acetate polymer to special silica particle. Both the initial speed of the adhesion between the sheeting and mortar and final adhesion performance are improved. The excellent waterproof performance was also confirmed by our original watertightness test. The sheeting is practically used for the construction of Keihan Electric Railways's Nakanoshima Line in Osaka, Japan.

View full abstract

Vacuum dewatering method with geotextile tube, which applied vacuum consolidation to Geotextile tube dehydration method, was newly 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. Effectiveness and dewatering mechanisms of the proposed method were discussed based on test results using clay with high water content like muddy water. As a result, it was shown that the proposed method can improve dewatering performance significantly due to the vacuum consolidation effect.

View full abstract

Multi-drain vacuum dewatering method is an easy method which used a vacuum pump and plastic board drains. Using this method, bottom sediments in muddy water condition can be dewatered until the condition of nearly liquid limit for several hours. The dewatered soils can be carried by damp truck. In this paper, Dewatering and purification system of bottom sediments using this method is newly proposed. A series of dewatering tests were carried out using 16 kinds of bottom sediments obtained in lakes, ports, and a tidal flat and then a series of purification tests were also carried out using "Natural Zeolite" as a purification agent. Based on test results, effectiveness and feasibility of the proposed system were verified.

View full abstract

Kumamoto rail yard of Kyushu Shinkansen is constructing on soft clay layer, so accelerated consolidation method is necessary. Therefore, in this area, considering construction schedule, cost economy and the effect on neighboring structures, Pre-Lord method and vacuum consolidation method used. Also, experimental embankment with accelerated consolidation method was constructed, and effect and influence of this method was evaluated. In this paper, we evaluated parameter and modeling of vacuum consolidation method by feedback analysis using actual data.

View full abstract

Results from a series of shaking table model tests on geo-grid reinforced soil retaining walls by using different geogrid models are discussed so as to investigate into the effects of material properties of the geo-grid models (i.e. pull out resistances, rapture strength and tensile rigidity) on seismic performance of the reinforced soil retaining walls. Based on the results from the shaking table model tests, residual displacements of wall facing and settlement of the backfill are almost equal although the material properties of the geo-grid models are largely different. It is also found that the deformation characteristics of the reinforced backfill investigated by using image analysis procedures are also quite similar.

View full abstract

Several high embankments in the Noto toll road were collapsed due to the Noto Hanto Earthquake in 2007. We investigated the geogrid reinforced embankment located in Ishikawa Pref. and Toyama Pref. after occurring the earthquake. Since the geogrid reinforced embankments were undamaged, it was verified that the geogrid reinforced embankment has high quake resistance. The collapsed embankments in the Noto toll road are restored by the geogrid reinforced embankment. To restore the embankments promptly, we used the large size sandbag as the wall surface of reinforced embankment. This paper repots the investigation of the state of the geogrid reinforced embankment and the method of restoration of the collapsed embankments in the Noto toll road.

View full abstract

In this paper, evaluation for the degree of damage of GRSW is discussed. In this method, shear strain of backfill material in the reinforced area is evaluated from the horizontal displacement of the wall. Then, occurrence of the slip line is decided based on the simple plastic theory. Since the past studies show that seismic stability of the GRSW depends upon the pullout resistance between geogrid and backfill material after the generation of slip line in the backfill, seismic stability of the GRSW having slip line in the reinforced area is evaluated from the results of the pullout test. Since our past study shows that seismic stability of the GRSW depends upon the pullout resistance between geogrid and backfill material, the seismic stability of GRSW after the formation of slip line is evaluated based on the results of pullout tests. Finally, the validity of the proposed method was verified with results of some centrifuge shaking table tests.

View full abstract

This paper reports the results of field observation and numerical analysis of full-scale model test for a new reinforced soil retaining wall system, having a vertical layer which absorbs the deformation between facing concrete brocks and reinforced backfill. The field observations and FE-analysis show that little earth pressure acts on the facing blocks and that the structure system is stable. A dynamic elastic-plastic FE-analysis which investigates the interaction behavior between the facing blocks and reinforced backfill, shows that the structure system is stable on the condition of earthquake.

View full abstract

A series of direct shear tests on granular materials either unreinforced or reinforced with geosynthetic reinforcement were performed. A large specimen size (60 cm-high and 80 cm-long and 50 cm-wide) was employed to accommodate a prototype geosynthetic reinforcement (a geogrid) as used in the field. Three different types of granular materials having different particle sizes were used to evaluate the effects of particle size on the reinforcing effects. The restraining condition at the top end of the reinforcement was controlled in such that, at the top end of the reinforcement, either the tensile force is kept constant or the vertical displacement is kept zero. The developing mechanism of the tensile reinforcing effect was investigated by measuring local tensile strains in the reinforcement. It is shown that the tensile-reinforcing effect increases with an increase in the particle size due to: 1) larger dilation of the shear zone, which increases the tensile strain in the reinforcement inside the shear zone; 2) subsequent larger extension of reinforcement in the shear zone, which mobilizes the anchorage force at a higher rate before the soil exhibits larger strain softening; and 3) larger anchorage capacity in the anchorage zone, which increases the maximum tensile load that can be mobilized in the reinforcement.

View full abstract

We constructed two full-size test embankments reinforced by a geocell. One of them was made by only loam soil which is recognized as problematic soils, while other was made by loam soil and macadam. We performed failure tests of the embankments after measuring the horizontal displacements and the heights of them for about two years. We can understand from the measurements and failure tests that the embankments made only by loam soils is stable and safe as well as other one. We can confirm the possibility of using surplus soils for the filling materials

View full abstract

This paper reports the results from a series of laboratory model tests and in-situ tests carried out to investigate the performance of the geocell reinforcement for bearing capacity of soils. At first, we carried out the middle-size model tests for sands to examine the tendency of supporting performance and supporting mechanisms. The bearing capacity, the vertical displacement under footing and the distribution of the local deformation are measured. Next, we carry out the in-situ simple bearing capacity tests to investigate the effect of geocell reinforcement for loam clay.

View full abstract

Recently, soil slopes reinforced by geo-cell, which is one of the three-dimentional geo-synthetics materials, have been gradually constructed in Japan. If we can use the local surplus soils as the materials into the cells, the geo-cell reinforced retaining wall is very useful and have many advantages for natural environments and construction costs. In this study, we investigated the condition of geo-cell reinforced soil retaining walls actually constructed in Niigata. The state after The Niigataken Chuetsu-oki Earthquake in 2007 was investigated. It compared it with the investigation before the earthquake.

View full abstract

During 1995 Hyogoken-Nanbu earthquake, heavy concrete spillway on the embankment of small reservoir were significantly damaged. Especially, it was pointed out that some spillways were detached from the embankment because of the inertia force, and the incidents could be the cause of secondary disaster in downstream area in floods. In this paper, firstly, a series of shaking table tests on heavy rigid spillway model was discussed. As the result, newly proposed lightweight spillway by geogrid has earthquake resistance. Moreover backfill ground was integrated by geogrid and affects the displacement and deformation of spillway.

View full abstract

The Lattice-Frame-Reinforced Sheet (LFR sheet) was constructed at the river revetment at The Shounai River. LFR sheet is surface stabilization method that has tubes made of woven textile which are filled with high mobility mortal. In this construction we needed not only surface stabilization but also the reed roots protection. Using LFR sheet at the temporary road, we could confirm protected of the reed roots. The space between lattices protects the reed roots. Compare LFR sheet with replacement to crushed stone method, LFR sheet is expensive but certain way to protect the reed roots and surface stability. LFR sheet was awarded Aich Environmental Prize 2008.

View full abstract

In a bend of pressure pipeline, thrust force is generated due to internal pressure. A concrete block is used at the bend to resist the thrust force. However the concrete block will be a weak point during earthquake. In our previous study, a lightweight thrust restraint using geogrids and an anchor plate was proposed. In addition, the advantage of the proposed thrust restraint was verified from results of laboratory model tests and full-scale tests, and the resistance mechanism was examined by numerical analyses. Based on the failure mechanism, the maximum lateral resistance was evaluated by solving equations for force equilibrium. In the present study, the lateral resistance of the proposed method was formulated considering the elongation of geogrids. In addition, results calculated by the proposed formula were compared with experimental results. As the results, it was concluded that the lateral resistance can be evaluated by proposed formula.

View full abstract

In order to reduce deformation of ballasted railroads during large earthquakes, concrete blocks are currently employed. In this study, several performance evaluations are conducted on a newly proposed method to reinforce ballasted railroads with stacked geosynthetic bags that are filled with ballast, since it is more economical and efficient for construction than the concrete blocks. It is confirmed that the proposed method has a sufficient resistance as a seismic measures.

View full abstract