• Title/Summary/Keyword: Foundation soil

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Investigation on Recently Developed Reinforced Soil Wall System (국내 보강토옹벽 신기술 조사 연구)

  • Lee, Kwang-Wu;Cho, Sam-Deok
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.158-167
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    • 2008
  • Reinforced earth wall system has been popularized since its introduction to Korean civil engineering society in early 1980's. Nowadays, the increased use of reinforced earth wall for the purpose of obtaining more land brings several additional demands such as environmental-friendly, better stable and constructible, and economical system. This paper introduces some recently developed reinforced earth wall systems with consideration of the current demands.

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A Computer Program for 2-D Fluid-Structure-Soil Interaction Analysis (2차원 유체- 구조물-지반 상호작용해석 전산프로그램)

  • 김재민
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.427-434
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    • 2000
  • This paper presents a computer program for a 2-D fluid-structure-soil interaction analysis. With this computer program the fluid can be modeled by a spurious free 4-node displacement-based fluid element which uses rotational penalty and mass projection technique in conjunction with the one point reduced integration scheme to remove the spurious zero energy modes. The structure and near field soil are discretized by the standard finite elements while the unbounded far field soil are discretized by the standard finite elements while the unbounded far field soil is represented by the frequency dependent dynamic infinite elements. Sine this method models directly the fluid-structure-soil system it can be applied to the dynamci analysis of 2-D liquid storage structure with complex geometry. For the purpose of verification dynamic analyses for tanks on a rigid foundation and on compliant embankment are carried out. Comparison of the present results with those by ANSYS program shows good agreement.

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Lateral capacity of piles in layered soil: a simple approach

  • Mandal, Bikash;Roy, Rana;Dutta, Sekhar Chandra
    • Structural Engineering and Mechanics
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    • v.44 no.5
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    • pp.571-584
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    • 2012
  • Appropriate assessment of lateral capacity of pile foundation is known to be a complex problem involving soil-structure interaction. Having reviewed the available methods in brief, relative paucity of simple and rational technique to evaluate lateral capacity of pile in layered soil is identified. In this context, two efficient approaches for the assessment of lateral capacity of short pile embedded in bi-layer cohesive deposit is developed. It is presumed that the allowable lateral capacity of short pile is generally dictated by the permissible lateral displacement within which pile-soil system may be assumed to be elastic. The applicability of the scheme, depicted through illustration, is believed to be of ample help at least for practical purpose.

Compressibility of broken rock-fine grain soil mixture

  • Xu, Ming;Song, Erxiang;Cao, Guangxu
    • Geomechanics and Engineering
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    • v.1 no.2
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    • pp.169-178
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    • 2009
  • Due to the enormous amount of fills required, broken rock-fine grain soil mixtures have been increasingly used in the construction of high-fill foundations for airports, railways and highways in the mountain areas of western China. However, the compressibility behavior of those broken rock-fine grain soil mixtures remains unknown, which impose great uncertainties for the performance of those high-fill foundations. In this research, the mixture of broken limestone and a fine grain soil, Douposi soil, is studied. Large oedometer tests have been performed on specimens with different soil content. This research reveals the significant influence of fine grains on the compressibility of the mixture, including immediate settlement, creep, as well as wetting deformation.

Probabilistic Approach on Railway Infrastructure Stability and Settlement Analysis

  • Lee, Sangho
    • International Journal of Railway
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    • v.6 no.2
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    • pp.45-52
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    • 2013
  • Railway construction needs vast soil investigation for its infrastructure foundation designs along the planned railway path to identify the design parameters for stability and serviceability checks. The soil investigation data are usually classified and grouped to decide design input parameters per each construction section and budget estimates. Deterministic design method which most civil engineer and practitioner are familiar with has a clear limitation in construction/maintenance budget control, and occasionally produced overdesigned or unsafe design problems. Instead of using a batch type analysis with predetermined input parameters, data population collected from site soil investigation and design load condition can be statistically estimated for the mean and variance to present the feature of data distribution and optimized with a best fitting probability function. Probabilistic approach using entire feature of design input data enables to predict the worst, best and most probable cases based on identified ranges of soil and load data, which will help railway designer select construction method to save the time and cost. This paper introduces two Monte Carlo simulations actually applied on estimation of retaining wall external stability and long term settlement of organic soil in soil investigation area for a recent high speed railway project.

Professional Engineer Yard - The construction example of deep cement mixing method for the soil improvement of soft ground in sports center structure foundation work around the mouth of Nakdong River (기술사 마당 - 낙동강(洛東江)주변의 체육센터시설물기초 연약지반(軟弱地盤)처리를 위한 DCMM 시공사례)

  • Cho, Kyoo-Yung;Kim, Jin-Eok;Jeong, Byeong-Chan
    • Journal of the Korean Professional Engineers Association
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    • v.44 no.6
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    • pp.45-50
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    • 2011
  • As the Deep Cement Mixing Method is composed of drilled natural soft soil structure and injected cement slurry to be mix together in it, the nature of excavated ground is influenced directly to the application of constructability. Also the nature of in situ soil is the main material, the mix design and construction work plan should be established before the investigation of soil which is performed through the whole site confirm the soil parameter before construction. The nature of investigated soil and water level as should be performed accurately.

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Studies on the Frost Heave Revelation and Deformation Behaviour due to Thawing of Weathered Granite Soils (화강암 풍화토의 동상 발현 및 융해에 따른 변형 거동에 관한 연구)

  • 류능환;최중대;류영선
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.37 no.3_4
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    • pp.61-71
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    • 1995
  • Natural ground is a composite consisted of the three phases of water, air and soil paircies. Among the three components, water as a material is weU understood but soil particles are not in foundation engineering. Especially, weathered granite soil generally shows a large volumetric expansion when they freeze. And, the stability and durability of the soil have shown decreased with repetitive freezing and thawing processes. These unique charcteristics may cause various construction and management problems if the soil is used as a construction material and foundation layers. This project was initiated to investigate the soil's physical and engineering characteristics resulting from freezing and freezing-thawing processes. Research results may be used as a basic data in solving various problems related to the soil's unique characteristics. The following conclusions were obtained: The degree of decomposition of weathered granite soil in Kangwon-do was very different between the West and East sides of the divide of the Dae-Kwan Ryung. Soil particles distributed wide from very coarse to fine particles. Consistency could be predicted with a function of P200 as LL=0.8 P200+20. Permeability ranged from 10-2 to 10-4cm/sec, moisture content from 15 to 20% and maximum dry density from 1.55 to 1.73 g /cmΥ$^3$ By compaction, soil particles easily crushed, D50 of soil particles decreased and specific surface significantly increased. Shear characteristics varied wide depending on the disturbance of soil. Strain characteristics influenced the soil's dynamic behviour. Elastic failure mode was observed if strain was less than 1O-4/s and plastic failure mode was observed if strain was more than 10-2/s. The elastic wave velocity in the soil rapidly increased if dry density became larger than 1.5 g /cm$^3$ and these values were Vp=250, Vg= 150, respectively. Frost heave ratio was the highest around 0 $^{\circ}C$ and the maximum frost heave pressure was observed when deformation ratio was less than 10% which was the stability state of soil freezing. The state had no relation with frost depth. Over freezing process was observed when drainage or suction freezing process was undergone. Drainage freezing process was observed if freezing velocity was high under confined pressure and suction frost process was occurred if the velocity was low under the same confined process.

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