• Title/Summary/Keyword: Embankment behavior

Search Result 173, Processing Time 0.024 seconds

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
    • /
    • v.32 no.5
    • /
    • pp.453-469
    • /
    • 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.

Assessment of tunnel stability according to height of embankment by numerical analysis (수치해석을 통한 성토 높이에 따른 터널 안정성 평가 연구)

  • Lee, Kang-Hyun;Lee, Sangrae;Kim, Nag-Young
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.23 no.1
    • /
    • pp.37-45
    • /
    • 2021
  • The construction of the tunnel portal should be careful because cover depth is shallow and it is difficult to exhibit the arching effect. Tunnel stability may be reduced with additional embankment above the portal of tunnel. In this study, in order to examine the stability of the tunnel according to additional embankment above the portal of tunnel, numerical analysis was performed while changing the ground conditions and height of embankment. As a result of the numerical analysis, it was found that the allowable flexural compressive stress of shotcrete and allowable axial force of rockbolts were exceeded when the height of additional embankment was 12 m in rock mass rating V. When considering the displacement, the range of the plastic region and the behavior of the support materials, the tunnel stability seems to be greatly reduced if the height of additional embankment above the portal of tunnel exceeds 10 m.

Comparison between 2D FEM Analysis using Elastic (visco)-plastic model and In-situ Behavior (성토가 주변지반에 미치는 영향에 대한 해석적 검증과 실측치의 비교분석)

  • 황성춘;김승렬
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2000.02a
    • /
    • pp.79-92
    • /
    • 2000
  • In this paper, comparison of the observed and the predicted ground deformations due to the construction of road embankment with peck drain near the construction site was made. Measurement of the ground deformation at the gasoline stand due to the construction of road embankment was made and it was compared with the predicted deformation results of Finite Element Method analysis made with Elasto-plastic and Elastic visco-plastic models. A well agreement was obtained between the measured and predicted ground deformations.

  • PDF

The Analysis of Tidal Effect on Stress-Strain Behavior in the Boundary Surface of Sea Dike Embankment (조석현상이 방조제 경계면의 응력-변형 거동에 미치는 영향 분석)

  • Eam, Sung Hoon
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.55 no.2
    • /
    • pp.1-8
    • /
    • 2013
  • This study was performed for the purpose of analyzing the effect of tide on the stress-strain behavior in the boundary surface of sea dike embankment. Tide is a dynamic condition, but there are not suitable numerical models to solve the dynamic embankment condition caused by tide. So the analysis was simplified to quasi dynamic as follow. First, seepage by tide was analyzed according to elapsed time, and the results of the analysis at every hour during one periodic cycle time of 12 hours were applied to the pore water pressure conditions of stress-strain analysis with hyperbolic model by Duncan and Chang. The place at which maximum shear strain took place in the analysis result moved up and down repeatedly along the boundary of the dredged sand fill section and the crashed stone filter section. The value of maximum shear strain was large at high water level of tide. This result means that contraction and relaxation occur in turn repeatedly at every specific position along the boundary, and the repeated action compact loose position with sand moved down from the upper position by gravity. The experiment with the small sea dike model showed the result consistent with the numerical analysis. The surface of sea side on the dike collapsed at high water level after a couple of repetition of the rising and falling of water.

Seismic performance evaluation of agricultural reservoir embankment based on overtopping prevention structures installation

  • Bo Ra Yun;Jung Hyun Ryu;Ji Sang Han;Dal Won Lee
    • Korean Journal of Agricultural Science
    • /
    • v.50 no.3
    • /
    • pp.469-484
    • /
    • 2023
  • In this study, three types of structures-stepped gabion retaining walls, vertical gabion retaining walls, and parapets-were installed on the dam floor crest to prevent the overflow of deteriorative homogeneous reservoirs. The acceleration response, displacement behavior, and pore water pressure ratio behavior were compared and evaluated using shaking-table model tests. The experimental conditions were set to 0.154 g in consideration of the domestic standard and the seismic acceleration range according to the magnitude of the earthquake, and the input waveform was applied with Pohang, Gongen, and artificial earthquake waves. The acceleration response according to the design ground acceleration increased as the height of the embankment increased, and the observed value were larger in the range of 1.1 to 2.1 times the input acceleration for all structures. The horizontal and vertical displacements exhibited maximum values on the upstream slope, and the embankment was evaluated as stable and included within the allowable range for all waveforms. The settlement ratio considering the similarity law exhibited the least change in the case of the parapet structure. The amplification ratio was 1.1 to 1.5 times in all structures, with the largest observed in the dam crest. The maximum excess pore water pressure ratio was in the range of 0.010 - 0.021, and the liquefaction evaluation standard was within 1.0, which was considered very stable.

Laboratory Tests and Numerical Simulations for Prediction of Stress-Stain Behavior Using Construction Materials for Embankment (제방축조재료의 응력-변형거동 예측을 위한 실내시험 및 수치해석)

  • Jeong, Sang-Guk;Koo, Ja-Kap
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.14 no.6
    • /
    • pp.215-219
    • /
    • 2010
  • The evaluation of the mechanical properties and behavior is very important for the design of embankment using granular materials. In this research, the lab. tests with Nak-dong river sand were conducted to find out mechanical properties related to stress-strain behavior. Also, numerical simulations which can express the behavior of granular material were conducted by distinct element method. Distinct element method can play a import role to predict stress-strain behavior for different confining stress and loading condition if micro-parameters can be estimated in specific condition.

A Case Study Of Dynamic Compacted Rock Embankment Design Considering Long Term Behavior (장기침하를 고려한 고성토 암버력 동다짐 지반의 설계사례)

  • Bae, Kyung-Tae;An, Sang-Yik;Park, Yong-Man;Kim, Kang-Kyu;Kim, Hyung-Suk;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2009.09a
    • /
    • pp.967-975
    • /
    • 2009
  • In order to control differential settlement and to secure the safety of super structure on a high rock embankment the designed static compaction is changed with dynamic compaction and piled raft method. The parameters for dynamic compaction design are obtained from a pilot test. In addition, numerical analyses are also carried out to figure out the length and quantity of piled raft that can restraint the differential settlement within allowance range.

  • PDF

Piping Analysis of Reservoir Embankment due to Leakage of Buried Box Culvert (저수지 제체 내 배수통관의 누수로 인한 파이핑 분석)

  • Kim, Han il;Yang, Hak Young;Kim, Young Muk
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.37 no.5
    • /
    • pp.787-799
    • /
    • 2017
  • Although the long-term leakage between the box culvert and the soil contact surface is one of the main causes of the failure in the embankment of the reservoir, there is a little studies on this matter. If a leakage occurs by the structure such as the buried box culvert of reservoir embankment is partially damaged, it is difficult to observe and there is a possibility of damage caused by piping. For these reasons, more research is necessary. In this study, the embankment type of the reservoir is divided into the core type and the homogeneous type when the damaged box culvert passing through the embankment of the reservoir is leaked due to the differential behavior of materials like differential settlement. In view of the condition, the seepage analysis of 2D was performed according to the water level change. The result of the study shows that the possibility of piping increases at the upper part rather than the bottom part of the box culvert when the leakage occurs to the box culvert passing through the embankment of the reservoir. Particularly, it is considered that the presence of the core helps to maintain the seepage stability of the embankment in case where the leakage occurs at the downstream side of the embankment. Also, if there is a drastic decrease on the internal pore water pressure in the embankment of reservoir, it is necessary to consider the possibility of piping.

Evaluation of Agricultural Reservoir Behavior by Seismic Shaking Table Test (지진 모형시험을 통한 농업용 저수지 거동 평가)

  • Lim, Seongyoon;Song, Changseob;Kim, Myeonghwan
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.57 no.3
    • /
    • pp.55-63
    • /
    • 2015
  • Embankment of agricultural reservoir started by four major rivers project. Most agricultural reservoirs must insure the agricultural water, they need must be ensured stability of embankment. Recently, there is a growing interest in seismic stability of structure by earthquake. Results of evaluation of the structural stability through seismic vibration test and numerical analysis, maximum displacement and the maximum acceleration is a similar trends. Appeared by increasing occurrence of the value of the displacement and acceleration of the structure with the result long period wave type in accordance with the seismic wave in the case of seismic waves, which shows the results of similar tendency as long period wave type consists of waveform seismic acceleration. Model test and numerical analysis results with in order to increase embankment agricultural reservoir, the displacement was found to ensure it is displayed within one percentage structural stability of the embankment.

Design Guidelines of Piled Bridge Abutment subjected to Lateral Soil Movements (교대말뚝기초의 측방이동 판정기준 분석)

  • 정상섬;이진형;서동희;김유석;장범수
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2002.03a
    • /
    • pp.381-388
    • /
    • 2002
  • A series of centrifuge model tests were performed to investigate the behavior of piled bridge abutment subjected to lateral soil movements induced by the construction of approach embankment. In these tests, both the depth of soft clay and the rate of embankment construction are chosen as key parameters to examine the effects on lateral soil movements. The depth of soft clay layer varies from 5.2 m to 11.6 m, and the rate of embankment construction has two types of staged construction(1m/30days, 1m/15days) and instant construction. It is shown that, the distribution of lateral flow induced by stage embankment construction has a trapezoidal distribution. And practical guidelines to check the possibility of some lateral movement of piled abutment were investigated. The validity of the proposed guidelines by centrifuge test was compared with the observed performance by lateral movement index, F(Japan Highway Public Corporation) and modified I index(Korea Highway Corporation). Based on the results obtained, the critical values of F and modified I, as a practical guidelines, are proposed to 0.03 and 2.0, respectively.

  • PDF