• Geotechnical Engineering
• /
• v.7 no.1
• /
• pp.33-40
• /
• 1991

This paper reports the application study of the ground reinforcement under a pipe joint. The soil-reinforcement interaction helps to minimize the stress concentration at joint. The settlement pattern and the earth pressure variation have been evaluated under the pipeline subjected to differential settlement. The pipeline is fixed at one side with the other side set free being loaded with a uniform surface loading. The problem has been studied by means of laboratory model test and flite element technique, and the analysis results are compared for both non-reinforced and reinforced cases to evaluate the effectiveness of the soil reinforcement for restraining the settlement of the pipeline.

• Journal of the Korean GEO-environmental Society
• /
• v.9 no.2
• /
• pp.67-74
• /
• 2008

Many industrialized countries of the world have many problems about the reuse of waste landfill area because of the increase of terminated waste disposal landfill. Especially, the effective use of the terminated waste disposal landfill nearby the urban area has been demanded, because of the lack of the usable land. However, in case of the construction of the building on such a landfill, ground settlement and reduced bearing capacity would be occurred without ground stabilization and proper reinforcement. This study is to evaluate the applicability of geosynthetics for the increment of bearing capacity of solid waste landfill ground. A numerical simulation has been undertaken to model a layer of weathered soil overlaying a layer of geosynthetic reinforcement and waste disposal ground. The proposed analytical model can be used to obtain surface settlement characteristic in the two-dimensional deformation related reinforcement.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.14 no.4
• /
• pp.933-939
• /
• 1994

This paper has primarily been directed to evaluate the beneficial effects of geogrid reinforcement in a medium sand on the ultimate bearing capacity (UBC) of a surface foundation. Also, this study was conducted to investigate the permanent settlement of a shallow square foundation in improving the cyclic load-settlement characteristics of reinforced sand deposits by conducting a series of laboratory model tests. Use of geogrids provides an economical and time efficient method for improving load-settlement and strength characteristics of weak soils. Especially the geogrid reinforced soil will be necessary in the case of foundation supporting machines, embankments for railroads, and foundations of structures in earthquake-prone areas. Finally, the test results indicate that the use of geogrid reinforcement in sand subgrades improves their performance under dynamic loads which shows promise for future work.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.12
• /
• pp.87-95
• /
• 2014

Recently, there are increasing technical needs for foundation retrofit project such as vertical extension of apartment building. This paper focuses on the load distribution characteristics of existing and reinforcing piles when reinforcing pile is installed to the existing foundation. Allowable bearing load was initially applied on the foundation slab supported with four existing piles and then, one reinforcing pile was installed at the center of foundation slab and additional load was applied. The experimental results showed the Load Distribution Ratio (LDR) between existing and reinforcing piles converged after the applied load exceeded allowable bearing capacity of all piles. Laboratory tests were also performed for the cases of 60 %, 80 %, 100 % unloading level of allowable bearing load. After unloading step, one reinforcing pile was installed at the center of foundation slab and additional load was applied. The results showed that reloading load level at which LDR between existing and reinforcing piles converged decreased as the amount of unloading load increased.

• Geotechnical Engineering
• /
• v.9 no.2
• /
• pp.55-64
• /
• 1993

When earth structures such as dykes or embankments are constructed on very soft clay foundation, unexpectedly large deformations of earth structures as well as clay foundation are encountered during and after construction. The final constructed section is composed of a portion of embankment above the existing ground level and that which penetrated into the soft foundation soil. This study is aimed to correctly estimate the shape of earth structures which penetrate some depth into the soft clay foundation. In this study the methods to predict penetration depth and deformation shape of embankment section after dumping of construction material. Model tests were carried out to prove the developed theory and FEM analysis. And when the mat is added, reinforcement effect was markedly noticed.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.17 no.1
• /
• pp.55-63
• /
• 2013

In this study, seismic performance was evaluated considering the deterioration level for the low-rise and moderate buildings with non-seismic details which are most common in Korea. Evaluation results showed that the deterioration condition is relatively good even after 24 years of construction but the seismic performance did not satisfy the protection index in the first and second evaluation. In case of the third evaluation, the goal performance was satisfied based on the interstory drift ratio but reinforcement is found to be necessary. Seismic performance was evaluated after the target buildings were reinforced in the walls, bracing, and damper. Results showed the interstory drift ratio drastically reduced regardless of reinforcement methods and satisfied the level of immediate occupancy. In case of wall reinforcement, however, base shear increased more than double which requires review on the existing foundation.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.16 no.3
• /
• pp.99-108
• /
• 2012

In this paper, to intend anticorrosive effect and weight reduction of conventional reinforced concrete slab, lightweight concrete slab reinforced with glass fiber reinforced polymer(GFRP) bar was considered and some basic behaviour of the slab were investigated. Measurement of splitting tensile strength and fracture energy of the concrete, a number of flexural experiment of the slab, numerical analysis using nonlinear finite element analysis, and comparison of the experimental results to the numerical analysis, were conducted. As a result, even the weight of the lightweight concrete slab could be reduced by about 28% than the normal concrete slab, failure load of the lightweight concrete slab was 36% smaller than the normal concrete slab. Such a thing can be attributed to the lower axial stiffness and lower bond strength of GFRP bar. In the numerical analysis, to consider decreasing property of bond strength of the lightweight concrete, interface element was used between the concrete and the GFRP bar elements and this method was shown to be a better way for the numerical analysis to approach the experimental results.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.3
• /
• pp.261-272
• /
• 2023

This research concentrates on the potential explosion hazards that could arise from unforeseen accidents in the rapidly proliferating hydrogen refueling stations and Energy Storage System(ESS) facilities. It underscores the pivotal role of structural protection technology in alleviating such risks. The research contributes primary data for the formulation of structure protection design by assessing the impact resistance across various reinforcement techniques used in cement composites. The experimental results elucidate that reinforced concrete, serving as the quintessential structural material, exhibits a 20% advancement in impact resistance in comparison to its non-reinforced counterpart. In situations typified by rapid loads, such as those seen with high-velocity impacts, the reinforcement of the matrix with fibers is demonstrably more beneficial than local reinforcement. These insights accentuate the importance of judiciously choosing the reinforcement method to augment impact resistance in structural design.

• Journal of the Korea Concrete Institute
• /
• v.22 no.1
• /
• pp.93-102
• /
• 2010

Recently, FRP usage for strengthening RC structures in civil engineering has been increasing. Especially, the use of FRP to strengthen structures against blast loading is growing rapidly. To estimate FRP retrofitting effect under blast loading, blast tests with nine $1,000{\times}1,000{\times}150\;mm$ RC panel specimens, which were retrofitted with carbon fiber reinforced polymer (CFRP), Polyurea, CFRP with Poly-urea and basalt fiber reinforced polymer (BFRP) have been carried out. The applied blast load was generated by the detonation of 15.88 kg ANFO explosive charge at 1.5 m standoff distance. The data acquisitions not only included blast waves of incident pressure, reflected pressure, and impulse, but also included central deflection and strains at steel, concrete, and FRP surfaces. The failure mode of each specimen was observed and compared with a control specimen. From the test results, the blast resistance of each retrofit material was determined. The test results of each retrofit material will provide the basic information for preliminary selection of retrofit material to achieve the target retrofit performance and protection level.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.6A
• /
• pp.965-976
• /
• 2006

A realistic lifetime seismic-reliability based approach is unavoidable to perform Life-Cycle Cost (LCC)-effective optimum design, maintenance, and retrofitting of structures against seismic risk. So far, though a number of researchers have proposed the LCC-based seismic design and retrofitting methodologies, most researchers have only focused on the methodological point. Accordingly, in most works, they have not been quantitatively considered critical factors such as the effects of seismic retrofit, maintenance, and environmental stressors on lifetime seismic reliability assessment of deteriorating structures. Thus, in this study, a systemic lifetime seismic reliability analysis methodology is proposed and a program HPYER-DRAIN2DX-DS is developed to perform the desired lifetime seismic reliability analysis. To demonstrate the applicability of the program, it is applied to an example bridge with or without seismic retrofit and maintenance strategies. From the numerical investigation, it may be positively stated that HYPER-DRAIN2DX-DS can be utilized as a useful numerical tool for LCC-effective optimum seismic design, maintenance, and retrofitting of bridges.