• Journal of the Korean GEO-environmental Society
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• v.18 no.12
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• pp.13-23
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• 2017

This paper discusses about the reinforcement materials and construction method in order to cope with roadbed settlement in operating railway. In Korea, concrete tracks have been introduced to urban railways, high-speed railways, and general railways, but some recently constructed concrete tracks have experienced roadbed settlements. Reinforcement of the railway roadbed is urgent task for safe operation of railway, but it is difficult to reinforce the roadbed and there are no case history of reinforcing railway roadbed under an operating railroad track. Therefore, in this study, the target performance level for roadbed reinforcement was determined, and infiltration and solidity injection efficiency were investigated for selected reinforcement materials. As a result of the study, it was found that the generally used reinforcement materials and methods for geotechnical works need to be improved for applying in railway roadbed reinforcement.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.96-102
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• 1998

The characteristics of roadbed are very important factors in the design of railways. Laboratory model tests were performed to investigate the effectiveness of geogrid placement in the subbase layers on reinforcement. Design parameters of reinforcement were determined through the laboratory model tests. The results indicated that geogrid reinforcement is increased the bearing capacity and reduced the settlement of railway foundation. The optimum length of geogrid reinforcement is about 4B. The effective depth of geogrid placement from the bottom of ballast is about 0.1B-0.2B depended on magnitude of applied load.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.906-909
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• 2005

The purpose of this paper is to study on the construction of roadbed with environmental friendly soil amendment agent and reinforced fiber. The special amendment agent and fiber used in this study has a function of soil-cement-agent solidification and reinforcement. A series of laboratory experiments including unconfined compressive strength, tensile strength, compaction test were carried out to investigate the physical and mechanical characteristics of roadbed treated by solidifying agent and fiber. The results of this research showed that the roadbed using poor soil could be efficiently constructed by treatment of this amendment agent and fiber.

• Journal of the Korean Geosynthetics Society
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• v.20 no.1
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• pp.9-19
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• 2021

This paper deals with the reinforcement performance of acrylate for reinforcing the settled railway roadbed. Concrete tracks have the advantage of reducing track maintenance costs and high resistance to track destruction. However, roadbed settlement is occurring in some construction sections, and the safety of railways is a serious concern because of difficulties in maintenance. Currently, maintenance through the track restoration method is being carried out in Korea as a way of roadbed settlement in concrete tracks, but continuous re-settlement can occur because the roadbed itself cannot be reinforced, and there are very few cases of reinforcement of railway roadbeds and field application. So the development of reinforcement materials and construction methods to reinforce railway roadbeds is required. Therefore, in this paper, acrylate was selected as reinforcement material for railway roadbed, and the reinforcement performance of acrylate was analyzed through experiment. As a result, it was analyzed that the acrylate can penetrate into a permeability coefficient of 1×10^-4 cm/sec, and secure uniaxial compression strength of 0.5 MPa/30min or more and stiffness of 80 MPa or more.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.526-533
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• 2001

Since 1970's in Germany and U.S.A., the studies on increasing the bearing capacity of railway roadbed using geogeid have been conducted for the repair, reinforcement, and extention of railways constructed on soft soils. In this study, the railway roadbed system reinforced with geogrids has been analyzed and investigated using finite element method and results of the previous studies were conducted in Korea and other nations. And the method for estimating the railway roadbed thickness was developed based on the equivalent method using the multi-layer theory and the deformation modulus Ev.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.614-619
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• 2002

Since 1980's in U.S.A and Japan, the studies on increasing the bearing capacity of railway roadbed using geocell have been conducted for repair and reinforcement of railways constructed on soft soils. In this study, the railway roadbed system reinforced with geocells has been analyzed and investigated results of the previous studies were conducted in Korea and other nations, And the method for estimating the railway roadbed thickness was developed based on the equivalent method using the multi-layer theory and the deformation modulus Ev.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.667-671
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• 2004

The purpose of this paper is to study on the construction of environmentally friendly roadbed by reinforcing type soil solidification agent. The soil amendment agent used in this study is friendly to the environment, and has a function of soil-cement-agent solidification. The soil amendment agent was admixed with reinforced fiber material for enhancement of strength and durability of roadbed. The project of trial field test of roadbed construction with special reinforcing soil treatment agent was performed in Gyunggido on December 2003. A series of field and laboratory experiments including unconfined compressive strength, permeability were carried out to investigate the physical and mechanical characteristics of solidified roadbed treated by this reinforced solidifying agent. The results of this research showed that the roadbed using normal and poor soil could be efficiently constructed by treatment of this reinforcing type solidification agent admixed with fiber material.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1546-1553
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• 2005

In this study, geotextiles was applied on the selected track-bed, which is relatively economical and efficient way to prevent the problem of mud-pumping and settlement. Field testing sections from Mock-haeng to Dong-ryang in the Chung-buk lines in Korea were selected to investigate the state of track and roadbed. And three places were chosen among 1,700 spots where mud-pumping was frequently occurred and maintenance required. At the curved section with radius of 500m between Mock-haeng and Dong-ryang, we divided this testing site into 5 section and 4 different types of geotextile were installed and left the last section with no reinforcement. Total length of the test site was 200m and individual length of each site was 40 m. In order to understand the state and the strength of prepared roadbed, stiffness and physical properties of the roadbed soil were evaluated and analyzed. Also, after the installation, mud-pumping, settlement of elastic or plastic sleeper, failure of track, wheel-loads, lateral force and earth pressures were investigated.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.734-743
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• 2005

In this study, geotextiles was applied on the selected track-bed, which is relatively economical and efficient way to prevent the problem of mud-pumping and settlement. Field testing sections from Mock-haeng to Dong-ryang in the Chung-La lines in Korea were selected to investigate the state of track and roadbed. And three places were chosen among 1,700 spots where mud-pumping was frequently occurred and maintenance required. At the curved section with radius of 500m between Mock-haeng and Dong-ryang, we divided this testing site into 5 section and 4 different types of geotextile were installed and left the last section with no reinforcement. Total length of the test site was 200m and individual length of each site was 40 m. In order to understand the state and the strength of prepared roadbed, stiffness and physical properties of the roadbed soil were evaluated and analyzed. Also, after the installation, mud-pumping, settlement of elastic or plastic sleeper, failure of track, wheel-loads, lateral force and earth pressures were investigated.

• Journal of the Korean Geosynthetics Society
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• v.1 no.1
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• pp.23-29
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• 2002

Since 1980's in U.S.A and Japan, the studies on increasing the bearing capacity of railway roadbed using geocell system have been conducted for repair and reinforcement of railways constructed on soft soils. In this study, the railway roadbed reinforced with geocell system, used for repair and reinforcement of existing railways in Korea, has been analyzed and investigated the results of the previous studies conducted in Korea and other nations. And the method for estimating the railway roadbed thickness was developed based on the equivalent method using the multi-layer theory and the deformation modulus Ev.