The Basing of Stabilization Parameters of a Fortified Railway Bed

In this technological era, development of infrastructures such as railway, roadway, bridges, special buildings etc. are increasing tremendously. Due to paucity of useful land and strength of soil, engineers have to improve soil properties like shear strength, bulk density, permeability, void ratio, water holding capacity etc. by adopting different ground improvement techniques. The one of the method among ground improvement techniques is reinforcing the soil with materials like steel, stainless steel, aluminium, fibers, fiber glass, nylon, and polyester, polyamides in the form of other strips or grids, combination of grids and Geotextiles. The main purpose of reinforcing a soil mass is to improve its stability, increasing its bearing capacity and reduce Settlements and Lateral deformations. Geotextiles and geomembranes, widely speaking are synthetic fibres used to stabilize structures built on soil having poor conditions. Lots of ground improvement techniques are available in today's market. Such as vibro compaction, vibro replacement, ground freezing, grouted stone columns, dry deep soil mixing, vacuum consolidation, preloading, heating etc. Among them geocell reinforcement is recently developed technique. The aim of this study is to increase bearing capacity of soil in railway embankment by ground improvement technique named as "geocell".

MATEC Web of Conferences, 2019

Investigation of damages of the subgrade slope in combination with its overwetting and rolling stock loading, which significantly affects safety traffic of the railway transport, has been carried out. The complex method of slope stability estimation of the subgrade is developed, which includes calculation of loads and vibration action of rolling stock on the main site of the subgrade, as well as the dynamic model of vibrations propagation in the body of the subgrade embankment and the model of plastic deformations accumulation. Dynamic and nonlinear plastic models are based on a finite-element model of the cross section of the subgrade. The plastic model takes into account the characteristics of soil strength of the subgrade, depending on the area of the vibration load impact. The developed method allows to carry out the estimation of external and internal factors impact on occurrence of subgrade destruction, which is of practical value for safety state estimation of the railway transport.

MATEC Web of Conferences, 2019

The rise in highway design and construction requires ensuring the reliability of these infrastructure projects. This is especially important for construction on weak soils. The number of design solutions is equally on the rise for reinforcing the grounds of soil transport structures. Examples include the use of various types of piles, and structures made of sand, gravel and other draining soils placed in a shell of geosynthetic material. The article presents the results of the authors' work on the substantiation and implementation of various constructive solutions to strengthen the insufficiently strong bases on railway and highway construction facilities (railway lines Losevo-Kamennogorsk, Moscow-Kazan high-speed railroad, Moscow-Saint Petersburg high-speed highway, etc.).

Soil is the deciding result of the impact of the atmosphere, alleviation (rise, introduction, and slant of landscape), living beings, and guardian materials (unique minerals) associating after some time. Absence of sufficient street system to take into account the expanded request and expanded trouble in streets prompting incessant support has dependably been a major issue in Andhra Pradesh state. Investigating the plausibility of construction materials for subgrade and embankment adjustment will help the street building area to develop a more grounded, sturdy and financial configuration. Soil layers beneath banks need to give basic soundness to bolster movement loads forced upon them. Soil embankment when discovered frail and unsatisfactory to convey loads from asphalt layers, soil embankment should be balanced out. Utilization of stabilizers, for example, coir fiber and soil reinforcement may enhance load conveying limit of soil embankment, which likewise goes about as fortifying material. In this paper we had chosen road embankments of district road from Kankipadu to Gudivada length of 23 Km. We collected soil samples and conducted experiments, from that experiments we obtained engineering properties of soil. We designed a embankment in software and calculated a factor of safety for sliding which is greater than 1.5 when soil reinforcement is considered.

Frontiers in Built Environment, 2023

A high-quality railway track resting on an excellent foundation is required to support high-speed railway transportation. The foundations of high-speed railway tracks are generally constructed on the lifted embankment with the improved ground using different reinforcement agents like geosynthetics and rigid lateral support. The present study performed dynamic finite element simulations on a ballasted rail track laid over a geosynthetically reinforced embankment with and without facing wall support. Three foundation geometries were analyzed to examine the effect of facing wall support and geosynthetics on the lateral resistance of the foundation. An area loaded with a constant pressure was moved at a constant speed, causing the load motion at different speeds in the 90-360 km/h range. Different parameters were calculated at node paths to help understand the lateral effect of moving load. The results showed that the lateral resistance based on nodal acceleration and velocity increased with facing wall support in the range of 40%-57%. Any increment over the minimum facing wall thickness of 300 mm does not significantly increase lateral resistance. Geosynthetics provided a vital function in the foundations with a less bulk volume of soil and increased the lateral resistance by 10%.

IJAEM, 2021

Increased capacity in the railway infrastructure demands the improvement of poor subgradestrata. Modernization and expansion of railway networks whole across country requires theconstructionofraillinespassingthroughsoilwhich maynotbeacceptedto supportsuchheavyrepeated rolling axle loads. Problems of failure of formation due to poor subgrade capacity andsubgrade attrition is quite severe in Indian Railways. Several remedies has been purposed tillnow by using various external additives such as brick dust, cinder, ashes of fly ash, pond ashesin combination with lime, stone columns etc. Still formation improvement against bearingcapacityfailureisthemainchallengingrehabili tationwork.Thispaperenlightenstheimprovement of formation strata comprising of black cotton soil using strength improvementadditives such as brick dust, fly ashand optimizedlime percentage.Lab test have beenperformed for natural strata and with additives. It has been seen that there is significantimprovementinCBRvalueupto42percenta ge.Decrementinshrinkageandswellingpropertyin the soil with optimized additives has been recorded. Numerical modelling using FEMtechnique has been simulated for the natural founding soil and improved soil. Various layershave been modelled using Mohr-coulomb elasto-plastic soil model and sleepers and rail aselastic model. It has been observed that there is excessive vertical displacement due to rollingloadspartiallyunableintransferringthestressesi ntodeepformationlevel.Useofimprovedsoilformatio nstrataleadingtopropertransferofload,consequentlyr eductioninverticalsettlements. Keywords:Poorsubgrade,numericalmodelling,CBR, railwayinfrastructure,foundingsoil,settlement.

MATEC Web of Conferences, 2019

Nowadays requirements for strength and stability of railway subgrade are increased. It occurs due to raising of train speed and axle load. Some sections of subgrade that were previously considered stable do not satisfy safety requirements. In this regard, superstructure reinforcing solutions need to be developed. This paper highlights ballast and subgrade reinforcement applications of geogrids in railway infrastructure. In recent years, geosynthetics are widely used for this purpose. The paper describes recent studies, which helped to identify geosynthetics reinforcement influence on ballast layer and subgrade. Influence of axial load on stress in ballast and subgrade was determined. Obtained data showed that design solutions are required to provide subgrade top bearing capacity in terms of operation with axle loads over 220 kN. Design solution is protective layers installation of polystyrene or geogrids. Five types of geosynthetic materials were placed on the top of subgrade to stu...

Vibroengineering procedia, 2024

The article presents the results of determining the strength and deformation characteristics of the soils of the roadbed. Models of road structures located on a weak soil base are also considered, with the justification of design schemes reflecting the basic physical conditions of the structure. The strength of weak soils under the influence of vibration loads depends on their variety and porosity. The higher the density of the soil, the higher its dynamic stability and the greater the values of vibration accelerations, which cause a decrease in its strength. When comparing the calculated data of the dynamic deflection of a weak soil base with experimental data, it was found that the discrepancy in quantitative values does not exceed 10 %, which is quite acceptable for this kind of research. The results obtained and the accepted models of road structures are recommended to be used in calculations of the stability of embankment slopes of the roadbed, as well as in calculations of the precipitation of the embankment body on weak foundations.

Frontiers in Built Environment, 2020

Use of the geosynthetics to strengthen the soil is one of the highly desirable techniques under static and dynamic loads. The present study describes the experimental and numerical studies performed on the geosynthetic reinforced subgrade subjected to repeated vehicle loads. The cyclic plate load tests were conducted on the sand subgrade reinforced with planar and 3D geosynthetic reinforcements. The vehicle load was simulated by applying a repeated load of magnitude 275 kPa with 1 Hz frequency on the reinforced subgrade. Results of the experimental investigations revealed that the performance of the subgrade soil improved significantly in the presence of reinforcements. The estimated parameters illustrated the threefold reduction in settlement of the subgrade in the presence of reinforcement. Further, the heaving of the subgrade soil was found completely arrested with the use of geosynthetic reinforcement. The three-dimensional geocell reinforcement performed effectively as compared to planar geogrids under dynamic load. The measured pressure values at different depth demonstrated a significant reduction in the pressure in the presence of reinforcements. Besides, numerical simulations were performed using PLAXIS 2D to understand pressure and settlement distribution patterns in the reinforced subgrade. In overall, a good agreement was observed between numerical and experimental results.