The subgrade of old railway tracks often exhibits poor geotechnical behaviour, particularly regarding the soils on which the ballast layer rests. Such poor behaviour implies significant maintenance costs and possession times. The reinforcement of subgrade soils by injection of binders may mitigate these malfunctions, but previous applications showed some limitations, and the quality of the results

Cyclic stress is applied to a soil element in the ground when vehicles or trains pass repeatedly on roads and railway tracks. This cyclic stress induced by traffic load gives rise to ground settlement, which sometimes causes damage such as cracks and ruts in road pavement. Therefore, estimating the settlement of granular materials is necessary for sustainable road design. For this study, a hollow cylindrical

Ionic stabilization is one of the non-traditional methods of soil stabilization. It is an advantageous stabilization method of being economic and utilizing liquid agents that can easily diffuse through soil and stabilize it. While several studies have been undertaken on ionic stabilization, the experience is still not sufficient enough and thus more research work is needed to understand the mechanism

This research provides an innovative combination of an adaptive neuro-fuzzy inference system (ANFIS) model for solving a nonlinear and complex problem related to soil shear strength prediction. The new hybrid model is optimized by an optimization technique i.e., henry gas solubility optimization (HGSO), called as HGSO-ANFIS. In predicting soil shear strength, the results of liquid limit, specific gravity

The mechanized excavation of tunnels generally requires the injection of a grout material between the segmental lining and the ground. This material has an important role for the support system and governs the segmental lining loading, also because of the significant evolution of its mechanical characteristics over time. In this work, an accurate experimentation on the two-component material was conducted

Railways are one of the largest transportation networks in the world. One of the key subgrade problems of railway track is associated with progressive shear failure (PSF). To-date, limited number of studies have addressed failure mechanism associated with the PSF, especially extending the mechanics of unsaturated soils. In this paper, the PSF mechanism is studied with the aid of computer program that

The design of rail tracks is often challenged by the highly compressible behaviour of soft estuarine clays over which they must pass. It is prudent that the realistic long-term behaviour of subgrade materials under repeated loading applied by fast moving heavy haul trains is properly understood. One feature that should not be ignored when estimating the long-term performance of track foundations is

Geothermal pavements represents a novel approach to shallow geothermal energy applications, in which horizontal ground heat exchangers are implemented within the pavement structure instead of traditional purpose-built trenches, thus decreasing capital costs. This study aims to better understand the feasibility and potential of these systems, by investigating the thermal response of the ground in a

The permanent railway track deformation caused by regular train traffic is important for infrastructure managers and railway contractors, as it determines the railway track quality. Although several successful approaches have been made to address the topic of the permanent railway track deformation, these have only been applied at specific locations, and have not yet been successfully applied at a

Design procedures for Geosynthetic Reinforced Column-Supported (GRCS) embankments should consider both internal stability arising from failure of single columns and external stability arising from failure of the embankment as a whole unit. A number of possible failure mechanisms for external stability due to slip circle failure and sliding failure of group of columns as a single unit are discussed

This paper aims to use the discrete element method (DEM) to study the performance of discarded off-the-road (OTR) tire chips under compression. The results of small-scale laboratory tests were used to calibrate a model built in PFC3D. This model was validated using the results of a large-scale laboratory experiment. The results show that the discrepancy between the calculated strain and the strain

This paper presents a series of large-scale laboratory experiments conducted on pavement sections to evaluate the performance of geogrid-reinforced base layer overlying various subgrade conditions (resilient modulus ranging between 10 MPa and 72 MPa). Four types of geogrids with different tensile strengths, aperture sizes, and polymer types were used to investigate the influence of geogrids on the

For tunnels built in the saturated silty sand ground, fine particles may be migrated into tunnels through seams of tunnel segmental joints and then seepage erosion is triggered, which may induce ground settlement. However, the process from fine particles erosion to the stress redistribution and soil properties’ change surrounding the tunnel and ground settlement has not been clarified up to now. For

Rail transit and highway transportation have flourished in the process of urbanization by virtue of their respective advantages, facilitating people’s travel but also producing harmful environmental vibrations. For an accurate analysis of source characteristics and propagation laws of train-induced vibrations, a field measurement was carried out in Shenzhen, China, where a double-line subway passes

This study aims to verify the suitability and reinforcement behavior of newly designed bored piles with retaining walls (BPRWs) for cutting-slope stabilization in the Tibet Plateau. As the first BPRWs prevention works in the alpine and hypoxic areas, full-scale performance testing is conducted of the high cutting slopes along the Lhasa-Nyingchi Railway under construction. Amid the construction processes

With the expansion of existing networks of underground system, many metro tunnels are excavated in a pair undercrossing existing tunnels. The new excavations will affect the stress distribution and settlement behavior of the existing tunnels, particularly when the clearance is small. Generally, the construction of the second undercrossing tunnel induces more settlement in the upper tunnels compared

Geosynthetic reinforcement is a lucrative solution for stabilizing the recurring failure of slopes. This paper presents an efficient probabilistic approach to analyze the internal stability of geosynthetic reinforced slopes (GRSs) resting on a soil deposit subjected to harmonic base shaking. Collocation based Stochastic Response Surface (SRS) method is used for the same. The deterministic analysis

A systematic dynamic triaxial series of tests on replicated rough rock joints were carried out, and results clearly highlight the strength attenuation as a function of joint degradation with respect to the number of loading cycles. A novel semi-empirical mathematical model to evaluate the equivalent dynamic shear strength (EDSS) of rock joint is proposed and validated with experimental results based

Long-term improvement in behaviour of soil subjected to lime treatment depends on the mechanism of its implementation. In-situ lime-treated fine-grained soil is often subjected to ‘kneading action’ developed by Pad-foot roller. The mechanism underlying the effect of kneading on lime-treated soil remains less investigated. Unconfined Compressive Strength (UCS) and microstructural modification of the

It has been shown that wrapping granular soil with geotextile significantly increases its bearing capacity. This finding, recently, has extended the use of soilbags to construct permanent structures. This paper investigates the compressive behavior of a new geo- column called the soilbag column. Several compression tests were performed for both end-bearing and floating columns with different diameters

Development of unconfined compression strength (UCS) and resilient modulus (MR) of chemically treated soil was investigated. Test samples were cured at room temperature from 1 to 28 days. Numerous other physical and index properties were used to characterize the treated and untreated soils. The work involved 18 different combinations of soils and chemical stabilizers including, cement kiln dust (CKD)

This study explored the coupling effect of the recycled ash and natural fibers to control the expansive soil's strength and durability attributes. The bottom ash (BA) was used to chemically treat the expansive soil and coir fibers (CF) as reinforcement against tensile cracking. The sustainable use of BA and CF to stabilize the expansive soil has been demonstrated by assessing - swelling behavior, mechanical

Understanding ballast layer dynamic response and long-term behavior under moving train loads is necessary for optimization of railway track performance. This paper discussed an advanced testing effort undertaken in a controlled laboratory environment for the measurement of dynamic load responses via multitude of installed sensors and the development of validated computer models and simulation tools

The evaluation of the mechanical behavior of soils should be considered as an important step for material selection and pavement design. The analyses of the elastic and plastic behaviors of the pavement unbound materials have generally been based on resilient modulus (RM) and permanent deformation (PD) tests, respectively. Such mechanical characteristics are significantly affected by factors including

In the recent past years, the importance of reliability analysis and risk assessment in solving Geotechnical Engineering problems is underlined in literature. This study is aimed to show the feasibility of Random Set Finite Element Method (RS-FEM) and Event Tree Analysis (ETA) in assessing the reliability and risk to fatality of urban excavations. In order to fulfill this aim, a case study (22-meter

As a new type of soft ground treatment technology, the geosynthetic-encased stone column (GESC) has been extensively used in engineering of roads and highways. In order to investigate the bearing mechanism of GESCs under cyclic loading, a series of experiments and numerical simulations were carried out using the proportional model. This paper described these changes in settlement and pile-soil stress

Deep vibro compaction (vibroflotation) is a widely-used ground improvement technique in granular soils. During the compaction process, the vibrator body is in constant interaction with the compacted soil. The changing ground conditions influence the motion behavior, making it possible to use the deep vibrator not only as a compaction device but also as a measurement tool. Within the scope of the current

Arching is regarded as a ubiquitous phenomenon in geomaterials where a new stress field is created following partial, induced displacements in the geomaterial. In the past, less attention has been paid to the deformations associated with the arching effect. The Digital Image Correlation (DIC) technique was implemented to map the shear and volumetric strain fields where arching occurred in a dense sand

In this study, a series of shear wave velocity tests were conducted on two types of sand-gravel mixtures with a wide range of particle size distributions. The effect of the particle shape on the small-strain shear modulus (Gmax) was investigated using a customized, large-scale triaxial apparatus. The results showed that Gmax increases with the decrease in particle roundness when the uniformity coefficient

Current Japanese design guide uses mechanical-empirical criteria to predict the failure loading number against fatigue cracking and rutting. However, these criteria have some limitations that the variation in moduli of base and subgrade layer due to the fluctuation in water contents, freeze–thaw history, and stress states are not considered. As well known, these factors greatly affect the soil mechanical

The reuse of construction and demolition wastes (C&D wastes) as unbound granular materials (UGMs) to construct pavement base and subbase courses is of great potential, while the cyclic behaviors of unbound C&D wastes under traffic loadings still lack the support of test data. To investigate the traffic-induced resilient and permanent deformation behaviors as well as the shear and particle breakage

Transition zones in railway track networks are locations that suffer from the considerable changes in track support structures which result in the abrupt change in track stiffness furthermore causing severe damage to the railway track system. Hence, this study aims to develop a novel flowable soil as backfill material for railway bridge approach which resolves the sudden change in track stiffness at

With the increasing production of construction and demolition waste (CDW), the use of CDW as a road base has become a sustainable and eco-friendly disposal approach. The aggregate crushing value is an essential index in the construction of road bases and is defined as the mass percentage of fine particles after a confined compression test of recycled CDW. In this study, experiments and numerical simulations

Construction and demolition (C&D) waste and scrap tires contribute to huge portions of the waste generated worldwide. One of the most effective and practical ways to eliminate the need to send C&D waste and scrap tires to landfills is to recycle and reuse them in civil and construction projects. On the other hand, the shear behavior of the granular aggregates has a significant influence on the performance

Advanced reliability analysis of road-slope stability in a brittle and faulted rockmass terrain by several techniques is described in this paper. The proposed analysis integrates several classical methods for the analysis of slope stability. The methods include remote sensing technique together with kinematic analysis, Finite Element Method (FEM), and Finite Difference Method (FDM). The Sentinel-2B

Scour, defined by the loss of geomaterials surrounding a foundation support system, is a primary cause of bridge failure in the United States and worldwide. Work herein presents a comprehensive review of the current state of knowledge on geotechnical aspects of erodibility, factors influencing pier scour, factors complicating pier scour assessment, and databases available on erodibility and pier scour

The cement-mixed soils technique is an efficient solution to improve the ground geomechanical properties in infrastructures and construction projects. This paper presents a systematic laboratory study to investigate the optimum water-to-cement ratio existence on the unconfined compressive strength. The soil compaction is controlled during these tests. The results showed that the maximum unconfined

Intensive urban growth leads the need of rail road tracks to be constructed on marginal soils as well as soils with very low strength. Application of geosynthetic has been shown to be effective in reducing excessive settlement and lateral displacement of tracks over soft subgrade under cyclic loading. Tests were performed on full paneled 1:3 scale model railway tracks to evaluate deformation and post-cyclic

Underground structures/machines may undergo upward and downward movements due to construction activities or environmental changes. The ground state could be significantly disturbed by previous construction and subsequent structural movements. In this study, alternant active and passive trapdoor tests simulating the ground disturbance were conducted to explore the progressive failure of the overlying

The paper presents a numerical analysis to investigate the temporal effect of shoulder cleaning on ballast drainage performance at various fouling conditions. Two parameters, the fouling index (FI) and the fouling profile (FP) are proposed to quantitatively represent the fouling conditions. A computational fluid dynamics (CFD) model including the Darcy-Forchheimer’s law to take into account the effect

A majority of literature indicates that geosynthetic inclusion in flexible pavement bases, subjected to highway loading, improves performance by reducing rutting or vertical pressure on weak subgrade layers. Instances where geosynthetics were less successful in highway pavements included strong subgrade soils and/or thick pavement layers. Thus, understanding the improvement that can be expected from

Localized Water Pressure (LWP) on tunnel means water pressure concentrating on partial areas of tunnel periphery instead of distributing evenly all around tunnels. High LWP generally occurs in tunnels crossing mountain areas with faults and fracture zones or results from clogging of the water drainage system of tunnels. High LWP on tunnels could lead to severe structural cracks and leakages. A mountain

Soil stabilization with chemical additives is a reliable engineering practice for improving the mechanical behaviour of low bearing soils. The present study investigates the effect of dunder as an organic waste produced during the distillation of ethanol which contains 85% water, on the compressive strength of a reactive clay. In this study, two non-traditional soil stabilization techniques (i.e.,

Currently, heavy hammer compaction method (HHCM) and quasi-static-compaction method (QSCM) are primarily used to produce the unbound graded aggregate materials (UGAM) samples and their mechanical properties are measured to guide the design and construction of the UGAM base. However, few studies have focused on the mechanical properties of the UGAM produced using vertical-vibration compaction method

The development of plastic deformation in flexible pavements has been a topic of research for several decades. Different models are available to predict this type of distress. However, the conditions defined by high loads with different stress paths than those traditionally considered during the development of performance models may cause their application to analyze non-standard vehicles to be limiting

Crushed waste rocks (CWR), generated from mining operations, have been widely used for the construction of mine haul roads because of their low-cost, high-strength, and availability. Resilient modulus is a necessary input to mechanistic design for mine haul roads, but its determination usually requires advanced and complex equipment such as repeated load triaxial (RLT) test. Repeated load CBR (RLCBR)

Bridges are critical nodes in the transportation system, especially those crossing wide rivers and seas. Once in service, bridge foundations and the surrounding soils will act as a system together and are subjected to erosion caused by the flows. For more than one century, researchers and engineers have made significant efforts to understand the scour process and its mechanisms to protect bridge foundations

Railway lines typically use traditional sloping embankments as the principal means of track support. However, the use of Geosynthetically Reinforced Soil (GRS) systems have gained popularity as alternatives to conventional embankments, particularly for high-speed lines in Japan. This system requires less ground stabilization/improvement and less land take than conventional embankments due to its smaller

This paper studies the discrete element modeling (DEM) of the thermal-geomechanical effect of recycled concrete aggregate (RCA) assemblies when harnessing renewable geothermal energy from pavement bases. This research study aims to simulate the behavior of RCA under repeated load triaxial test (RLT) at temperatures varying from 20 °C to 80 °C, to simulate temperature effects when harnessing geothermal

One common type of reinforced wall is the back-to-back mechanically stabilized earth wall. These are used extensively for narrow road embankments, pedestrian ramps, bridge abutments and railway systems. In the current study, a series of 1g shaking table tests were conducted to determine the dynamic performance of back-to-back strip-reinforced walls (BBSRWs). The models were constructed with different

Several reinforced soil wall failures were reported to have occurred at facing connections with reinforcing layers. These failures were generally attributed to reinforcement downdrag, which accompanies differential settlements between facings and backfills in reinforced soil walls. Overlooking reinforcement downdrag forces in design can result in underestimation of reinforcement loads at facing connections

The present work has the purpose of presenting the geotechnical and mechanical characterization of the fine sandy lateritic soil (SAFL), as well as its performance in the field as sub-ballast layer in railway pavement. The activity in the field is the application of this material in the project of expansion of the rail yard in the municipality of Açailândia - MA. Despite the fact that SAFLs are properly

Given the substantially increased demand for increased axle loads of heavy haul trains, there is an imperative need to develop sustainable track infrastructure. When subjected to heavy axle loading, ballast aggregates rapidly break down, compromising the particle friction and associated load bearing capacity. Therefore, understanding the deformation and degradation (breakage) of ballast subjected to

This study aims at developing a gene expression programming (GEP) model and an artificial neural network (ANN) model to predict the resilient modulus (MR) of compacted pavement subgrade soils based on their physical properties, external stress states, and environmental factors. A database of 2813 MR measurements derived from 12 subgrade soils with different moisture-temperature histories was established

Cement stabilized soil as pavement base and sub-base materials has been extensively applied in various countries. Nevertheless, cement stabilized soil in tropical countries undergoes cracking problems and premature pavement distress, due to cyclic wet and dry seasons. Natural rubber latex (NRL) can be used as an additive to improve the serviceability and durability of cement stabilized soil. The effect

Some issues concerning railway routes are related to avoiding uneven deformations, rail roughness, and increased dynamic loads. Lack of transition zones at the entrance and exit of bridges intensifies the above-mentioned failures due to sudden changes in track stiffness. The main objective of this article is to investigate the effects of approach slab length, thickness, and travel speed on the transition

The essential task of the ground reinforcement techniques is to keep the rock as stable as possible. In particular passive rock bolt should resist the rock movements along its entire length and through the resulting reaction forces, to improve the load-bearing capacity of the rock. Among different calculation techniques, the calculations based on Block Reinforcement Procedure (BRP) was used in this

With the thermal disturbance caused by engineering construction and global warming, thaw consolidation has become a primary source of subgrade deformation in permafrost regions. Based on the large-strain consolidation theory described by the updated Lagrangian, we study the thermal stability and the thaw consolidation in an ordinary subgrade at the warm and ice-rich permafrost (WIRP) site of the Beiluhe