라테라이트로 구성된 라오스 비포장도로의 품질 향상을 위한 개선공법의 적정치환두께 연구

A study on the appropriate replacement thickness of improvement methods to improve the quality of unpaved roads composed of mainly laterite in Lao PDR

The main roads in Lao PDR are unpaved and made of laterite, which has the disadvantage of reducing bearing capacity during rainy season or squalls and causing soil and sand to flow out. In this study, the appropriate replacement thickness of three types of improvement methods (CTB, ATB, and Lean Con"c) was calculated through computer analysis to improve the quality of unpaved roads in Laos, which are mainly composed of laterite. As a result of engineering classification by sampling the soil of the unpaved road, A-2-7 (High-plasticity silts) according to the AASHTO classification and SP, CL, and ML according to the USCS classification were obtained. Based on engineering classification, the condition of unpaved roads was divided into 5 types (SP, SM, very stiff clay (dry season), medium clay, and very soft clay), and computerized analysis was performed in FLAC 3D using the HL-93 truck tandem model. was carried out. As a result of computer analysis, it was confirmed that the maximum deflection decreases according to the replacement thickness of the improved method. In the case of ATB, horizontal and vertical strains (εt,εz) were calculated to be the largest in all conditions. In the case of Lean Con’c, the horizontal strain and vertical strain were calculated to be the smallest in all conditions, and the amount of change according to replacement thickness was the smallest. As a result of calculating the appropriate replacement thickness in the upper layer of unpaved roads in all conditions, it is 10 to 20 cm for CTB, more than 20 cm for ATB, and 5 to 10 cm for Lean Con’c

The main roads in Lao PDR are unpaved and made of laterite, which has the disadvantage of reducing bearing capacity during rainy season or squalls and causing soil and sand to flow out. In this study, the appropriate replacement thickness of three types of improvement methods (CTB, ATB, and Lean Con"c) was calculated through computer analysis to improve the quality of unpaved roads in Laos, which are mainly composed of laterite. As a result of engineering classification by sampling the soil of the unpaved road, A-2-7 (High-plasticity silts) according to the AASHTO classification and SP, CL, and ML according to the USCS classification were obtained. Based on engineering classification, the condition of unpaved roads was divided into 5 types (SP, SM, very stiff clay (dry season), medium clay, and very soft clay), and computerized analysis was performed in FLAC 3D using the HL-93 truck tandem model. was carried out. As a result of computer analysis, it was confirmed that the maximum deflection decreases according to the replacement thickness of the improved method. In the case of ATB, horizontal and vertical strains (εt,εz) were calculated to be the largest in all conditions. In the case of Lean Con’c, the horizontal strain and vertical strain were calculated to be the smallest in all conditions, and the amount of change according to replacement thickness was the smallest. As a result of calculating the appropriate replacement thickness in the upper layer of unpaved roads in all conditions, it is 10 to 20 cm for CTB, more than 20 cm for ATB, and 5 to 10 cm for Lean Con’c