• 제목/요약/키워드: Unconfined compression strength

검색결과 247건 처리시간 0.028초

고화재 혼합처리를 이용한 월드컵 주경기장 부지의 개량에 관한 연구 (Study on the Improvement of world-cup stadium field using Stabilizer)

  • 천병식;권형석;전진규;양정호
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1999년도 가을 학술발표회 논문집
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    • pp.263-270
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    • 1999
  • In country, for 2002 World-cup the peak is to construct soccer playground. the stabilizing method by additives is mainly applied of permanent improvement for bearing capacity of structure foundation and for strength, durability and transformation of road pavement layer except for construction machine's trafficability and bearing capacity. This study is on soft ground improvement of $\bigcirc$$\bigcirc$ world-cup stadium field. construction field constitutes of very various layers and after construction the lawn grass should be planted on the surface of the earth and in addition, chemical effects should be limited from improved ground layer. Mixing soft clay in field with three domestic representative additives, it evaluated the unconfined compression strength. In the results, after curing during 28 days the objective strength has been obtained on about 5% combination ratio.

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섬유보강 혼합경량토의 역학적 특성 비교 (Comparison of Mechanical Characteristics of Fiber-Reinforced Lightweight Soils)

  • 김윤태;한우종
    • 한국해양공학회지
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    • 제22권4호
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    • pp.51-58
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    • 2008
  • The objective of this study was to investigate the mechanical characteristics of fiber-reinforced lightweight soil using waste fishing net or monofilament for recycling both dredged soils and bottom ash. Reinforced lightweight soil consists of dredged soil, cement, air foam, and bottom ash. Waste fishing net or monoiament was added the mixture in order to increase the shear strength of the lightweight soil. Test specimens were fabricated with various mixing conditions, including waste fishing net content and monofilament content. Several series of unconfined compression tests and direct shear tests were carried out. From the experimental results, it was found that the unconfined compressive strength, as well as the stress-strain behavior of reinforced lightweight soil was strongly influenced by mixing conditions. In this study, the maximum increase in shear strength was obtained with either a 0.5% content of monofilament or 0.25% waste fishing net. The unconfined compressive strength of reinforced lightweight soil with monofilament was greater than that of reinforced lightweight soil with waste fishing net.

Predicting unconfined compression strength and split tensile strength of soil-cement via artificial neural networks

  • Luis Pereira;Luis Godinho;Fernando G. Branco
    • Geomechanics and Engineering
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    • 재33권6호
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    • pp.611-624
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    • 2023
  • Soil properties make it attractive as a building material due to its mechanical strength, aesthetically appearance, plasticity, and low cost. However, it is frequently necessary to improve and stabilize the soil mechanical properties with binders. Soil-cement is applied for purposes ranging from housing to dams, roads and foundations. Unconfined compression strength (UCS) and split tensile strength (CD) are essential mechanical parameters for ascertaining the aptitude of soil-cement for a given application. However, quantifying these parameters requires specimen preparation, testing, and several weeks. Methodologies that allowed accurate estimation of mechanical parameters in shorter time would represent an important advance in order to ensure shorter deliverable timeline and reduce the amount of laboratory work. In this work, an extensive campaign of UCS and CD tests was carried out in a sandy soil from the Leiria region (Portugal). Then, using the machine learning tool Neural Pattern Recognition of the MATLAB software, a prediction of these two parameters based on six input parameters was made. The results, especially those obtained with resource to a Bayesian regularization-backpropagation algorithm, are frankly positive, with a forecast success percentage over 90% and very low root mean square error (RMSE).

낙동강유역 시멘트혼합토의 강도특성 (Strength characteristics of cemented sand of Nak-dong river)

  • 김영수;정우섭;김기영;이상웅
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2006년도 춘계 학술발표회 논문집
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    • pp.808-817
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    • 2006
  • There were huge damages of human beings and their properties in many areas of the basin of the Nak-Dong river by the unusual weather and the localized downpour recently. In this research against disasters, we want to know the special quality of strength of the cemented sand that is mixed with cement and poor-graded sand which is the materials of riverbed in the basin of the Nak-Dong river as levee's material. For that, we want to provide the fundamental data which need in the examination of adaptation of levee's material, design and analysis by investigating compressive strength by curing period and cement ratio, elastic modulus and stress by transformation from compaction test, CBR test, unconfined compression test, triaxial compression test as changing ratio of sand and cement from 2% to 8% at two points in the basin of the Nak-Dong river.

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Study of geotechnical properties of a gypsiferous soil treated with lime and silica fume

  • Moayyeri, Neda;Oulapour, Masoud;Haghighi, Ali
    • Geomechanics and Engineering
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    • 제17권2호
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    • pp.195-206
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    • 2019
  • The gypsiferous soils are significantly sensitive to moisture and the water has a severe destructive effect on them. Therefore, the effect of lime and silica fume addition on their mechanical properties, when subjected to water, is investigated. Gypsiferous soil specimens were mixed with 1, 2 and 3% lime and 1, 3, 5 and 7% silica fume, in terms of the dry weight of soil. The specimens were mixed at optimum moisture content and cured for 24 hours, 7 and 28 days. 86 specimens in the sizes of unconfined compression strength test mold were prepared to perform unconfined compressive strength and durability tests. The results proved that adding even 1% of each of these additives can lead to a 15 times increase in unconfined compressive strength, compared with untreated specimen, and this increases as the curing time is prolonged. Also, after soaking, the compressive strength of the specimens stabilized with 2 and 3% lime plus different percentages of silica fume was considerably higher than before soaking. The durability of the treated specimens increased significantly after soaking. Direct shear tests showed that lime treatment is more efficient than silica fume treatment. Moreover, it is concluded that the initial tangent modulus and the strain at failure increased as the normal stress of the test was increased. Also, the higher lime contents, up to certain limits, increase the shear strength. Therefore, simultaneous use of lime and silica fume is recommended to improve the geotechnical properties of gypsiferous soils.

시료성형에 따른 점성토의 변형.강도 특성에 관한 연구 (A Study on the Strength and Deformation Characteristics of Clay due to the Specimen Shaping)

  • 박종수;박춘식;장정욱
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.1227-1232
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    • 2005
  • This study carried out unconfined compression tests to identify deformation and strength characteristics of clay. The conclusions are presented in the following. (1) The comparison of unconfined compression strengths according to specimen disturbance showed great differences, except for a few data. (2) The comparison of ${E_{50}}'s$ according to specimen disturbance proved that the two values were similar in general. (3) The comparison of strains at the peak according to specimen disturbance showed that non-shaped specimens had been slightly more disturbed in general. (4) The comparison of $E_{50}/q_u$ also suggested that non-shaped specimens had been slightly more disturbed in general.

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시멘트계 고화재에 의해 혼합처리된 지반의 설계정수에 관한 연구 (A Study on the Design-parameter of Mixed Ground by Using Cement-type Stabilizer)

  • 천병식;임해식;전진규
    • 한국지반공학회논문집
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    • 제16권2호
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    • pp.79-89
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    • 2000
  • The application of stabilization method has increased because of short construction periods, no environmental problems with dumped and replaced soil, assurance of required strength and economical effect with mid to small size construction. The unconfined and triaxial(UU-condition) compression tests were executed with each mixing sample for the study of the improvement effects and the effect of design-parameters by the stabilization methods. Three typical stabilizers, which are representative in Korea, were applied in this study, and three common soils(very soft clay, general weathered soil, common clay), which are common in Korea, were used in this study. In this study, the effect of engineering factors(soils, stabilizers and water contents, etc.) which are important parameters for the improvement effects of mixed ground by stabilizers, was analyzed. As results, the tendencies of design-parameters(unconfined compression strength, deformation modulus and strength parameter) are presented and the criteria of the application of stabilization methods are suggested.

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철도 강화노반재료의 정ㆍ동적 특성 분석 (Analysis of Static and Dynamic Characteristics of Reinforced Roadbed Materials)

  • 황선근;신민호;이성혁;이시한;최찬용
    • 한국철도학회논문집
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    • 제3권1호
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    • pp.34-41
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    • 2000
  • The analysis of static and dynamic characteristics of reinforced roadbed materials was performed through model and laboratory tests. The strength characteristic of reinforced roadbed materials such as HMS-25 and soil were investigated through the unconfined axial compression test, the model soil box test and the combined resonant column and torsional shear test. The unconfined axial compression strength of HMS-25 shows a steady increasement in strength due to the chemical hardening reaction between HMS-25 and water. The result of model soil box test reveals that railroad roadbed of HMS-25 is better than that of soil in several aspects, such as, bearing capacity and settlement. The combined resonant column and torsional shear test result indicates that shear modulus of HMS-25 and soil increase with the power of 0.5 to the confining pressure and linear relationship to normalized shear modulus and damping ratio.

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저소성 실트지반의 비배수 전단강도 특성을 고려한 CPTU 콘계수 평가 (Evaluation of CPTU Cone Factor of Silty Soil with Low Plasticity Focusing on Undrained Shear Strength Characteristics)

  • 김주현
    • 한국지반신소재학회논문집
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    • 제16권1호
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    • pp.73-83
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    • 2017
  • 모래 및 실트 함유량이 우세한 서해안 저소성 지반(인천, 화성, 군산)에서 실시된 실내 및 현장시험으로부터 얻어진 비배수전단 강도를 이용하여 피에조콘계수(Nkt)를 분석한 후, 이에 대한 적용성을 평가하였다. 인천, 화성 및 군산지역에서 얻어진 일축압축 강도에 의한 콘계수(Nkt)는 19~23, 간이 CU 강도에 의한 값은 13~13.8, 현장베인강도에 의한 값은 11.6~13.1로 평가되었다. 이는 저소성 실트 지반조건에서 일축압축강도가 과소평가되는 원인에 의한 것으로 간이 CU 강도 적용조건과 비교했을 때 콘계수(Nkt)가 약 1.8배 전후로 커지며 분산되는 경향을 나타냈다. 저소성 실트 지반에서 수행된 CPTU 데이터를 이용하여 콘계수(Nkt)를 평가할 때에는 지반의 입도분포, 액소성한계 등의 물리적 특성, 지층 내의 sandseam 분포 등으로 인한 콘선단저항(qt) 및 주면마찰력(fs)의 불규칙한 분포, 간극수압계수(Bq)를 종합적으로 분석하여 수행하는 것이 바람직할 것으로 판단된다.

세립분 함유량에 따른 동결 사질토의 응력-변형률-강도 특성 (Stress-Strain-Strength Characteristics of Frozen Sands with Various Fine Contents)

  • 채덕호;황범식;조완제
    • 한국지반환경공학회 논문집
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    • 제16권6호
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    • pp.31-38
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    • 2015
  • 최근 우리나라는 러시아 극동 지역의 천연파이프 건설과 제2남극기지인 장보고 기지건설이 이루어지면서 영구동토지반에서의 구조물 건설에 대한 관심이 증대되고 있다. 세립분 함유량이 동결된 사질토의 역학적 거동에 미치는 영향을 파악하기 위하여 온도 -5, -10, $-15^{\circ}C$의 조건에서 세립분 함유량 0, 5, 10, 15%의 시료에 대해 일축압축시험을 수행하였다. 동결 사질토를 성형하기 위해 입도가 균일한(SP) 주문진 표준사와 소성성이 낮은 실트(ML)인 카올리나이트를 사용하였다. 성형된 동결 사질토를 사용하여 온도를 제어할 수 있는 냉동 체임버에서 일축압축실험을 수행하였고 강도 및 강성특성을 파악하기 위해 최대 일축압축강도와 변형계수를 분석하였다. 그 결과 동결 사질토의 강도 및 강성은 세립분 함유량이 증가할수록 감소하는 경향을 보이고 온도가 낮아짐에 따라 증가하는 경향을 보였다.