• Geomechanics and Engineering
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• 제11권5호
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• pp.625-638
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• 2016

This paper presents field study and numerical modeling results for a single-cell low-fill concrete box culvert under a flexible pavement subjected to traffic loading. The culvert in the field test was instrumented with displacement transducers to capture the deformations resulting from different combinations of static and traffic loads. A low-boy truck with a known axle configuration and loads was used to apply seven static load combinations and traffic loads at different speeds. Deflections under the culvert roof were measured during loading. Soil and pavement samples were obtained by drilling operation on the test site. The properties of the soil and pavement layers were determined in the laboratory. A 3-D numerical model of the culvert was developed using a finite difference program FLAC3D. Linear elastic models were used for the pavement layers and soil. The numerical results with the material properties determined in the laboratory were compared with the field test results. The observed deflections in the field test were generally smaller under moving loads than static loads. The maximum deflections measured during the static and traffic loads were 0.6 mm and 0.41 mm respectively. The deflections computed by the numerical method were in good agreement with those observed in the field test. The deflection profiles obtained from the field test and the numerical simulation suggest that the traffic load acted more like a concentrated load distributed over a limited area on the culvert. Elastic models for culverts, pavement layers, and surrounding soil are appropriate for numerical modeling of box culverts under loading for load rating purposes.

• Steel and Composite Structures
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• 제27권2호
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• pp.217-227
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• 2018

This paper utilizes 3D FEM to provide deeper insights about the structural behaviour of a 6.1 m span steel culvert, which was previously tested under extreme loading. The effect of different input parameters pertaining to the backfill soil has been investigated, where the structural response is compared to field measurements. The interface choice between the steel and soil materials was also studied. The results enabled to realize the major influence of the friction angle on the load effects. Moreover, the analyses showed some differences concerning the estimation of failure load, whereas reasons beyond this outcome were arguably presented and discussed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.373-378
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• 2000

Zinc galvanized steel plates(sections) of annular corrugations have been used in buried steel culverts. These structures are referred to by a variety of names such as flexible pipes, buried pipes, soil-steel bridges, corrugated steel culverts, and etc. Buried corrugated steel structures show flexible behaviour under the soil load. compared with concrete box structures. Finite element analysis was performed to suggest the reasonable connecting method between the flexible steel culverts and the rigid concrete box. It was predicted that perfectly constrained connections could induce the excessive stress in steel plates. Therefore elastic bearing connections that allow vertical displacement at the connecting point were applied.

• Geomechanics and Engineering
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• 제22권1호
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• pp.49-63
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• 2020

Studying the critical response characteristics of box culverts with diverse geometrical configurations under seismic excitations is a necessary step to develop a reasonable design method. In this work, a numerical parametric study is conducted on various soil-culvert systems, aiming to highlight the critical difference in the seismic performances between three- and four-sided culverts. Two-dimensional numerical models consider a variety of burial depths, flexibility ratios and foundation widths, assuming a visco-elastic soil condition, which permits to compare with the analytical solutions and previous studies. The results show that flexible three-sided culverts at a shallow depth considerably amplify the spectral acceleration and Arias intensity. Larger racking deformation and rocking rotation are also predicted for the three-sided culverts, but the bottom slab influence decreases with increasing burial depth and foundation width. The bottom slab combined with the burial depth and structural stiffness also significantly influences the magnitude and distribution of the dynamic earth pressure. The findings of this work shed light on the critical role of the bottom slab in the seismic responses of box culverts and may have a certain reference value for the preliminary seismic design using R-F relation.

• 대한토목학회논문집
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• 제39권6호
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• pp.789-799
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• 2019

교대, 통로박스 등 말뚝기초로 지지된 구조물에서는 침하가 거의 발생하지 않지만, 구조물 저면 하부에는 공동이 발생하게 된다. 이에 따른 문제점으로는 측면지반에서 공동으로 유출된 토사에 의해 구조물 측면 지반의 침하를 가속화하여 더 큰 침하가 발생하게 된다. 따라서 말뚝 기초로 지지된 구조물 하부의 공동 발생으로 인한 문제점을 예방하고자 구조물의 측면에 쉽게 설치가 가능한 토사유입차단판(soil Flow Protector; 이하 'FLP')이 개발되었다. 본 연구에서는 FLP의 침하감소 효과를 입증하고 최적 길이를 산정하고자 실내모형실험을 수행하였고, 그 결과 FLP의 설치함으로서 측면지반의 침하량이 감소하고 공동으로의 토사 유출을 방지하였고, FLP의 강성이 작으면 상부의 토압은 정지 또는 주동영역이 되어 안정성에 유리하지 않지만, 충분히 크면 상부의 토압은 수동영역이 되어 안정성에 유리하다. 또한 FLP의 강성이 작은 경우에는 일정 길이 비 이상에서는 오히려 감소하였으나, 큰 경우에는 설치길이가 증가할수록 침하량 감소에 효과적이다. 이에 따른 박스구조물 높이(H = 250 mm)에 대한 최적 길이 비는 연성 1.38, 강성 0.73으로 산정되었다.