An attempt has been made to examine numerically, based on an elasto-plastic finite elements (FE) analysis, soil unit weight-ground displacement response due to laying of single and twin circular tunnels which are supported by an internal isotropic pressure (σi); the case σi= 0 implies an unsupported tunnel. The soil mass has been assumed to be linearly elastic and perfectly plastic obeying the Mohr-Coulomb

The pressure to achieve a higher speed of train operation has increased in the last few years due to the development of high-speed railway lines. In the presence of soft soils, this speed increase is not possible without undertaking soil improvement measures, since the critical speed is lower than the desired speed of train operation. One of the most widely used soil improvement techniques is that

A reliable prediction of the soil properties mixed with recycled material is considered as an ultimate goal of many geotechnical laboratory works. In this study, after planning and conducting a series of laboratory works, some basic properties of marine clay treated with recycled tiles together with their unconfined compressive strength (UCS) values were obtained. Then, these basic properties were

The settlement of ground-supported transportation infrastructures may vary greatly depending on the uncertainties related to compressibility properties and overconsolidation of clay. These uncertainties can be considered systematically by means of reliability analysis where the probability distribution of consolidation settlement is evaluated. Hence, this paper applies two well-known reliability methods

Cement-treated sand reinforced with fiber (CTSF) has been extensively utilized as the base and subbase layers in road and pavement applications to enhance the mechanical properties of cement-treated sand (CTS). This paper aims to study the influence of seven distinct types of synthetic fibers on the mechanical performances of CTSF specimens. The 5% cement and 2% fiber were mixed with sand and water

Liquefaction is mostly seen in saturated granular cohesionless soils when subjected to static and dynamic loading. Mainly in the constructed facilities, liquefaction on its way brings huge destruction. This study investigates the effectiveness of air injection method against liquefaction of saturated granular soil by cyclic triaxial apparatus. Strain controlled cyclic triaxial tests were performed

The infiltration of water in pavement layers due to heavy precipitation, snow melting, surface water flow, or ground water fluctuation can lead to a substantial change in pavement performance under traffic loading. The extent of this change depends on several complex and interdependent factors such as climatic and mechanical stressors, hydro-geological material properties, and traffic loads. Due to

To study the shear mechanical properties and deformation mechanism of the interface between cemented soil and warm frozen soil, the key parameters are provided for the design and evaluation of cemented soil structure in warm frozen soil ground. In this study, a series of negative temperature direct shear tests of the cast-in-place cemented soil-frozen soil interface were conducted under the influence

The T-shaped deep cement mixing (TDM) pile is a technique newly used to support embankments built on soft clays. However, comprehensive studies considering the cost effectiveness have not yet been performed, and the TDM pile bending moment behavior under embankment loading is not fully understood. Hence, this paper aims to evaluate the performance of a TDM pile-supported embankment (TPSE) over soft

To investigate the seismic performance of the immersed tunnel-foundation system, a spatial nonlinear model was established based on a modified model from Anastasopoulos (2007) method. In the spatial model, two key factors including temperature and prestress are synthetically considered. From a viewpoint of engineering practice, the influences of temperature loads and prestress tendons load on the seismic

The application of cement stabilized materials (CSM) in cold weather is prohibited by many federal and state agencies, as low temperatures can mitigate the cement hydration efficacy and retard the strength and stiffness growth of CSM. Due to the similarities between concrete and CSM, chemical admixtures that make concrete achieve full service capabilities under extreme conditions are quite likely to

This study aims at evaluating the influence of geosynthetic reinforcements on the structural improvement of asphalt overlays placed on distressed pavement layers using repeated load tests. Full-scale instrumented pavement models were constructed in an indoor steel tank measuring 1000 mm in length, 1000 mm in width and 1000 mm in depth. Full-scale instrumented pavement models consisted of a 650-mm-thick

A moving wheel load induces a principal stress rotation (PSR) in pavement foundation geomaterials including subgrade/subbase soils. Simulating such a stress condition is not possible with stress path tests conducted with conventional cyclic triaxial (CT) equipment. More complex stress paths such as a heart-shaped stress path are required to determine the deformation characteristics of these under a

The creep parameters of rockfill are usually derived from creep test in the laboratory, in which the loading period before the creep stage is much shorter than the construction period in the field. This difference might cause underestimation of the long-term settlement of high rockfill geostructures if an elastic-viscoplastic model based on isotach assumption is adopted. This paper aims to investigate

Buried conduits are commonly used for utility transportation around the world. Accordingly, to ensure the safe design and installation of conduits, it is important to understand soil-conduit interaction. This research paper presents a numerical investigation of the structural response of a conduit buried within a soil slope in response to applied surface pressure. Numerically simulated and analytically

This study evaluates the influence of inclined ground on the ultimate load-carrying capacity of rigid concrete pavements laying on unreinforced and reinforced soil embankments. The solution procedure is developed based on the kinematic approach of the limit analysis. The carrying capacity is sequentially obtained by satisfying the energy principle of the upper-bound theorem alongside the associated

The construction technology of shield tunnelling under an operating railway in an adverse stratum is complex and risky. The existing research results mostly focus on the settlement control of the tunnel under the existing structure, but they are not adequate to provide a systematic reference for shield tunnelling under an operating railway with strict requirements on the settlement control. Based on

The deformation and failure parameters of six mixtures of cement-modified loess have been determined based on direct tensile stress testing, indirect tensile test testing and unconfined compressive stress testing. Results have been used to determine the parameters of the Mohr-Coulomb failure criterion and the parameter of the Hoek-Brown failure criterion. The Hoek-Brown model clearly shows that results

With the ballast aging, the changes in the size and shape of the ballast particle reduce the drainage capacity, as well as cause a greater permanent deformation of the railroad ballast. Therefore, it is meaningful to investigate the effect of aging on the mechanical behavior of unsaturated ballast, and to estimate the cyclic plastic deformation by considering the aging effects. Here, “aging effect”

In this study, gene expression programming (GEP) and multi gene expression programming (MEP) are utilized to formulate new prediction models for determining the compaction parameters (ρdmax and wopt) of expansive soils. A total of 195 datasets with five input parameters (i.e., clay fraction CF, plastic limit wP, plasticity index IP, specific gravity Gs, maximum dry density ρdmax), and two output variables

Subways are fast, efficient, safe, comfortable and energy-saving transportation modes; however, the vibration generated by trains inevitably causes environmental pollution. In this paper, a new vibration isolation strategy is proposed by using Duxseal as the backfill material for tunnel lining (DX-Lining) to mitigate railway vibrations. DX-Lining was installed on Metro Lines in Qingdao, China. A series

The site investigation is a key part of the foundation analysis and design in the Hong Kong-Zhuhai-Macao Bridge (HZMB) mega project, as it provides accurate geotechnical parameters. This paper discusses about the collection of undisturbed soil samples, laboratory tests, and extensive piezocone penetration tests (CPTU) performed at the Pearl River Delta sites. First, soils were classified based on CPTU

Compaction is probably the industrial process more intensively used in road construction. The current compaction practice is based on the useful methodology proposed by Proctor (1933). This methodology intends to reproduce field compaction in the laboratory by applying a controlled mechanical energy to the soil and relating the dry density with the water content. However, recent developments in soil

Yazoo clay is highly plastic and has been associated in Mississippi with swelling problems and causes significant maintenance problems to the highway slopes. The infiltration of rainwater may create a perched water condition within the slopes, which may reduce the shear strength of the soil at the vadose zone. However, limited data is available on the wetting depth of highway slopes constructed on

In the development and maintenance of hydroelectric, mining, or oil industries, it is necessary to transport elements with non-conventional load magnitudes. The approval or rejection of the road network's use by vehicles carrying this type of load is conditioned on the pavement's capacity to withstand these special loading conditions without suffering considerable damage. The quantification of permanent

The paper presents a numerical modeling study on the upper-bound bearing capacity of footing on back-to-back-Mechanically Stabilized Earth (MSE) walls using the finite element limit analysis (FELA) method. Numerical simulations were validated against results from other numerical simulation studies. Parametric analyses were carried out subsequently to examine the influences that the distance between

Construction and demolition (C&D) wastes in pavement and railway structures are exposed to dynamic and static load combinations which results in breakage of particles. Past studies have investigated the effect of particle size and geometry on the breakage behavior of crushable materials; however, limited research has been conducted on the effect of loading rate and particle alignment on the breakage

The sustainable construction approach by utilizing recycled aggregates has increasingly been the focus of highway construction industries and local road authorities in recent years. The efficient usage of recycled aggregates for sustainable construction is owed to more than a decade of extensive experimental research aiming to remove uncertainties in the properties and performance of recycled aggregates

A power model (ε = A. NB) to estimate permanent strain (ε) from single-stage repeated load triaxial (RLT) tests can simulate both shakedown and incremental collapse. When the exponent B < 1, the ε versus load cycle number (N) plot concaves downwards, resembling that of a material that shakes down. When B > 1, the same plot concaves upwards, mimicking that of a material that incrementally collapses

A new procedure is proposed for evaluating active earth pressure subjected to earthquake vibration for three-dimensional (3D) unsaturated backfills comprised of cohesive soils, which is conducted by developing an upper bound analysis. The impact of diverse water tables on unsaturated soil-wall stability is incorporated into the comprehensive analysis, and it turns out to be indirect by exerting influence

Geosynthetic reinforced soil structures are widely used to support and enable transportation infrastructure. Given the importance of the transportation infrastructure within the context of disaster resilience, it is crucial to fully understand the response of the elements which constitute and support the infrastructure assets. This study presents and discusses the results of four heavily instrumented

Transportation infrastructure facilitates the accessibility and mobility of goods, people, and services through its vast network spanning across the USA. The departments of transportation (DOT) agencies face many challenges in monitoring and maintaining these infrastructure assets for continuing their service and operations, especially those located adjacent to slopes in rural and remote areas. Mobilizing

Geosynthetic-reinforced retaining (GRR) walls have been used to support spread footings constructed directly on the reinforced soil mass. This technology eliminates the need for traditional deep foundations, such as piles, to support bridges or buildings. Lateral facing deflection induced by footing loading is one of the key parameters that should be considered for design of GRR walls to support footings

Freeze-thaw cycles (FTC) are known to have an effect on railway track stability, safety, and performance. FTC are expected to become more frequent in the future due to climate change. This paper presents the results of a field investigation in which the mechanism of FTC development within the track embankment and its effect on the performance of railway tracks including track surface deformation and

Construction and demolition (C&D) waste materials have been used in a wide range of civil engineering applications, particularly as unbound pavement materials. A comprehensive understanding of the deformation and thermal properties of C&D materials is necessary for their usage in novel applications related to heat transfer in pavement unbound layers, such as geothermal pavements. This research study

The use of cement as a curing agent has been widely adopted in soft soil engineering to increase the strength of soft soil. The cemented soil is gradually exposed to the air and in a natural environment becomes unsaturated. Unconfined compressive strength (UCS) of the unsaturated cemented soils is a key parameter for assessing their strength behaviour. UCS determination of unsaturated cemented soils

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 dynamic performance of subgrade-bridge transitions containing track components (rails, sleepers, ballast, etc.) in heavy-haul railways has been extensively studied by researchers. However, the influence of subgrade filler distribution on the dynamic performance and stiffness variation has not been characterized due to the laying of track components. This study focuses on the dynamic characteristics

The excavation disturbed zone plays an important role in the evaluation of tunnel stability. The identification of the excavation disturbed zone is perceived as a main concern. Taking the material meso-structure into account, this paper investigates the construction mechanical behavior in heterogeneous sand cobble stratum and aims to precisely predict the excavation disturbed zone. Firstly, the meso-scale

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

This paper reports the results of soft computing-based models correlating L and N-type Schmidt hammer rebound numbers of rock. A data-independent database was compiled from available measurements reported in the literature, which was used to train and develop back propagating neural networks, genetic programming and least square method models for the prediction of L-type Schmidt hammer rebound numbers

Expansive soils are widespread in many parts of the world. Due to its low strength, high compressibility, and massive volumetric changes, these soils are a potential origin of damage to roads, buildings, foundations and other geo-infrastructure. Extensive research has been conducted on the utilisation of fly ash to stabilize expansive soils. This paper describes how the efficiency of fly ash based

Sinkhole incidents have increased rapidly in recent decades due to water main breaks. Although numerous researchers have recently conducted investigations in sinkhole phenomenon, most of the studies are related to natural sinkhole formation, underground cavity detection, and collapse analysis. Very few studies can be found in relation to the blowout stability of soils due to defective pipeline under

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

In practice, soil slopes are commonly unsaturated and may suffer from the adverse effects of earthquakes. Stability assessment of slopes subjected to earthquakes tends to consider whether the soils are dry or saturated while neglecting the time and spatial effects of seismic waves; in such assessments, the actual features cannot be reflected sufficiently. In the present study, a framework considering

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

Rail transport industry often desires to increase the freight capacities for heavy-haul trains to transport more goods. However, this requires an increase in the axle loads, which results in the railway foundation being subjected to higher cyclic stress ratio (CSR), causing significant subgrade distress. Recent laboratory investigations indicate that addition of kaolin to low-to-medium plasticity soils

The use of the recycled concrete aggregates (RCA) obtained from construction and demolition wastes not only reduces the demand for natural aggregate, which ultimately leads to economical and eco-friendly designs, but also improves the long-term performance of a conventional flexible pavement. This study aims to investigate the effects of using 100% RCA in the pavement subbase and base courses on the

Microencapsulated phase change material (mPCM) possess an excellent heat storage capacity, which could mitigate temperature fluctuation of soil during freezing/thawing in seasonally frozen regions. Two types of mPCM were investigated using scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infra-red spectroscopy and thermal analysis. Experiments including freezing/thawing

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

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 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

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

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

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

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