• Title/Summary/Keyword: Model Embankment

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Field measurement and numerical simulation of snow deposition on an embankment in snowdrift

  • Ma, Wenyong;Li, Feiqiang;Sun, Yuanchun;Li, Jianglong;Zhou, Xuanyi
    • Wind and Structures
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    • v.32 no.5
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    • pp.453-469
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    • 2021
  • Snow accumulation on the road frequently induces a big traffic problem in the cold snowy region. Accurate prediction on snow distribution is fundamental for solving drifting snow disasters on roads. The present study adopts the transient method to simulate the wind-induced snow distribution on embankment based on the mixture multiphase model and dynamic mesh technique. The simulation and field measurement are compared to confirm the applicability of the simulation. Furthermore, the process of snow accumulation is revealed. The effects of friction velocity and snow concentration on snow accumulation are analyzed to clarify its mechanism. The results show that the simulation agrees well with the field measurement in trends. Moreover, the snow accumulation on the embankment can be approximately divided into three stages with time, the snow firstly deposited on the windward side, then, accumulation occurs on the leeward side which induced by the wake vortex, finally, the snow distribution reaches an equilibrium state with the slope of approximately 7°. The friction velocity and duration have a significant influence on the snow accumulation, and the vortex scale directly affected the snow deposition range on the embankment leeward side.

An Experimental Study on Seepage Characteristics of Embedded Gravel and Rock Layer in the Embankment (성토층에 매설된 사력질층의 침투특성에 대한 실험적 연구)

  • Lee, Haeng-Woo;Chang, Pyoung-Wuck;Chang, Woong-Hee;Won, Jeong-Yun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.545-552
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    • 2005
  • For the purpose of studying on the seepage characteristics of embedded gravel layer in embankment, laboratory model tests were carried out. The embedded layer under embankment was $19{\sim}26mm$ diameter of gravel and those embankment materials were Saemangum dredged sand, river sand and mixed(1:1) sand with dredged and river one. Those permeability coefficients of three different sands are $5.00{\times}10^{-5}$, $3.00{\times}10^{-4}$, $7.50{\times}10^{-5}m/s$, respectively. Seepage characteristics of these results are as follows; 1) The Reynolds number of water flow through embedded gravel layer in three different permeable soils is less then 10, it is laminar flow. 2) These flow velocities through embedded gravel layer in soils are in proportion to these hydraulic gradients, it is Darcy flow. 3) These Darcian permeability coefficients of water flow through embedded gravel layer in soils show as $2.95{\times}10^{-3}$, $1.38{\times}10^{-2}$, $3.33{\times}10^{-3}$m/s, respectively, by varying permeability of embankment soils and embankment lengths. It is approximately 100 times of those permeability coefficients of embankment materials.

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3D Effect of Embankment Dam Geometry to Resistivity Data (3차원 댐구조가 전기비저항 자료에 미치는 영향)

  • Cho, In-Ky;Lee, Keun-Soo;Kang, Hye-Jin
    • Geophysics and Geophysical Exploration
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    • v.13 no.4
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    • pp.397-406
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    • 2010
  • Resistivity method is a practical and effective geophysical technique to detect leakage zones in embankment dams. Generally, resistivity survey conducted along the crest assumes that the embankment dam has a 2D structure. However, the 3D topography of the embankment distorts significantly resistivity data measured on anywhere of the dam. This study evaluates the influence from 3D effects created by specific dam geometry and effects of water level fluctuations through the 3D finite element modeling technique. Also, a comparison between different locations of survey line are carried out, and topographic correction technique is developed for the resistivity data obtained along the embankment dam. Furthermore, using synthetic resistivity data for an embankment dam model with leakage zone, detectability of leakage zones is estimated through 2.5D inversion.

Deformation mechanisms of shallow-buried pipelines during road widening: Field and numerical investigation

  • Long Chen;Chenlei Xie;Zi Ye;Yonghui Chen;Zhewei Chai;Yun Li
    • Geomechanics and Engineering
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    • v.38 no.1
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    • pp.15-28
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    • 2024
  • The rapid development of the economy has compelled the widen of highways, and the main challenge of this undertaking lies in the uneven settlement of road embankments. Through field and numerical experiments, this study explores the deformation mechanism of shallow buried pipelines due to road widening. The utilization of Plaxis3D software, which is adapt at simulating complex engineering geological conditions, enables the simulation of the settlement of both the central and right-side road embankments. Comparing with other numerical software such as ABAQUS and COMSOL, Plaxis provided more constitutive models including HS, HSS and Hoek-Brown model. The work concludes that the uneven settlement of road cross-sections is positively correlated with the horizontal distance from the pipeline, with a maximum settlement of 73 mm observed after construction. Furthermore, based on the Winkler's assumption, theoretical settlement and stress calculation methods are established. Results indicate that the maximum difference between the calculated values of this formula and simulated values is 1.9% and 7%, respectively. Additionally, the study investigates the stress and settlement of the pipeline's top under different angles to understand its behavior under various conditions. It finds that with traffic loads applied to the new embankment, a lever effect occurs on the lower pipeline, with the fulcrum located within the central isolation zone, leading to a transition in curve type from "single peak and single valley" to "double peak and single valley." Moreover, the settlement of pipelines on both sides of the central isolation zone and the normal stress of the pipeline's top section are symmetrical.

Hydraulic Characteristic Analysis of Final Closing considering Non-Darcy Flow (Non-Darcy 흐름특성을 고려한 최종체절 수리특성분석)

  • Choi, Hung-Sik
    • Journal of Korea Water Resources Association
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    • v.37 no.8
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    • pp.613-622
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    • 2004
  • The simulation results of final closing by the developed model considering the flows through tide embankment of non-Darcy and through sluice gate agree well to the observed data which shows the model applicability. In comparative analysis with observed data, the simulation results by Homma(1958) are more accurate than those by Na(1987). The free flow equation with discharge coefficient, regardless of free or submerged flows, by Na based on the submergence ratio is applicable to the engineering practices. Because two simulated discharges are greater than the actual one, the correction of discharge coefficients reflecting the irregular section of actual closing gap situation is necessary. In the hydraulic analysis of final closing, the flow through tide embankment has been generally analysed by Darcy. Hydraulic analysis by the correct discharge through tide embankment of non-Darcy flow is necessary, because the ratio between flows through tide embankment and closing gap is relatively great at final closing.

Prediction model of service life for tunnel structures in carbonation environments by genetic programming

  • Gao, Wei;Chen, Dongliang
    • Geomechanics and Engineering
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    • v.18 no.4
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    • pp.373-389
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    • 2019
  • It is important to study the problem of durability for tunnel structures. As a main influence on the durability of tunnel structures, carbonation-induced corrosion is studied. For the complicated environment of tunnel structures, based on the data samples from real engineering examples, the intelligent method (genetic programming) is used to construct the service life prediction model of tunnel structures. Based on the model, the prediction of service life for tunnel structures in carbonation environments is studied. Using the data samples from some tunnel engineering examples in China under carbonation environment, the proposed method is verified. In addition, the performance of the proposed prediction model is compared with that of the artificial neural network method. Finally, the effect of two main controlling parameters, the population size and sample size, on the performance of the prediction model by genetic programming is analyzed in detail.

Seismic Behavior of Deterioration Reservoir Embankment Using Dynamic Centrifugal Model Tests (동적원심모형실험에 의한 재개발 저수지의 동적 거동특성)

  • Park, Sung-Yong;Chang, Suk-Hyun;Lim, Hyun-Taek;Kim, Jung-Meyon;Kim, Yong-Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.58 no.3
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    • pp.91-100
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    • 2016
  • Recently, lots of damages have been lost because large magnitude earthquakes were occurred in the world. It has been increased the number of earthquakes in Korea. It needs improvement required for the repair of deteriorated reservoirs, reinforcement and raised reservoir coping with climate change and earthquake. This study aims to investigate the seismic behavior of deterioration reservoir levee using dynamic centrifugal model test. Therefore, two case tests in centrifugal field of 60 g, the result has provided the influence on the acceleration response, displacement, settlement and the pore water pressure of the reservoir with earthquakes. From the results larger displacement and acceleration response at the front side of reservoir embankment with poor-fabricated core in seismic condition may degrade overall stability. Reasonable reinforcement method of the raised reservoir embankment is required for ensuring long-term stability on earthquake.

Application of 2 Dimensional Numerical Model for Analysis of Riprap Weir Effect (Riprap Weir 효과 분석을 위한 2차원 수치해석 모형의 적용)

  • Kim, Sang-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.2
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    • pp.1441-1449
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    • 2015
  • At the bends of a river, the deflected flow of high energy erodes the embankment and transports sediment, ultimately changing the river's course. Such phenomena lead to instability of the embankment and may cause serious problems for nearby roads, land, or riverside structures. This study intends to analyze the characteristics of hydraulic flow at S-shaped bends after the installation of Riprap Weirs designed to prevent changes in a river's course and embankment erosion. An experimental channel was constructed by a two-dimensional CCHE2D model, and analyzed the characteristics of hydraulic flow with and without the Riprap Weirs. Also, the characteristics of hydraulic flow at the inner and outer sides of river bends and at points near reservoirs were analyzed, depending on the intervals between the Riprap Weirs.

ACCURACY IMPROVEMENT OF AN APPROXIMATE COST ESTIMATING MODEL FOR RIVER FACILITY CONSTRUCTION

  • Siwook Lee;Sungkwon Woo;Jeongyoon Lee;Inwook Choi
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1201-1208
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    • 2009
  • A making a decision of construction cost has important meaning and function for both contractor and owner in construction projects. Especially, it should be premised that estimating the construction cost in efficient and rational way in public construction, which is invested by government funds, for efficient execution of the budget and investment as a side of government. The systematic methodology for estimating construction cost approximately of a river facility construction project has not yet been established because of its unique characteristics including its relatively small project size in terms of cost. On this study, It collect and analyze a river facility construction historical cost data for develop an approximate cost estimating model for river applied by typical embankment section method and rate application of the others activity type. And it verify suitability of model through a that result of application of real river facility construction statement at developed model. By this study, it is expected to reasonable and systematic estimating construction cost through application of developed model.

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Stream Environment Monitoring using UAV Images (RGB, Thermal Infrared) (UAV 영상(RGB, 적외 열 영상)을 활용한 하천환경 모니터링)

  • Kang, Joon-Oh;Kim, Dal-Joo;Han, Woong-Ji;Lee, Yong-Chang
    • Journal of Urban Science
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    • v.6 no.2
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    • pp.17-27
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    • 2017
  • Recently, civil complaints have increased due to water pollution and bad smell in rivers. Therefore, attention is focused on improving the river environment. The purpose of this study is to acquire RGB and thermal infrared images using UAV for sewage outlet and to monitor the status of stream pollution and the applicability UAV based images for river embankment maintenance plan was examined. The accuracy of the 3D model was examination by SfM(Structure from Motion) based images analysis on river embankment maintenance area. Especially, The wastewater discharged from the factory near the river was detected as an thermal infrared images and the flow of wastewater was monitored. As a result of the study, we could monitor the cause and flows of wastewater pollution by detecting temperature change caused by wastewater inflow using UAV images. In addition, UAV based a high precision 3D model (DTM, Digital Topographic Map, Orthophoto Mosaic) was produced to obtain precise DSM(Digital Surface Model) and vegetation cover information for river embankment maintenance.

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