• Title/Summary/Keyword: Deformation Modulus

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LFWD Deformation Modulus changes which follows in Compaction Energy from Tentative Embankment Section (시험성토 단면에서의 다짐에너지에 따른 LFWD 변형계수의 변화)

  • Choi, Chan-Young;Kim, Hyun-Ki;Bae, Jae-Hoon
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1840-1847
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    • 2008
  • PLT where from site is used mainly with compaction maintenance of quality, CPLT and LFWD, in order to be a Young's modulus of using a direct arrival wave executed a site experiment. According to the roller compaction number of times measured the degree which changes and a promise management aptitude evaluation executed.

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Measurements of Elastic Moduli of Rock Cores Using Free-Free Resonance Tests (자유단 공진시험을 이용한 암석의 탄성계수 측정)

  • 목영진
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.10a
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    • pp.353-360
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    • 1998
  • Dynamic measurements are used rather sparingly to determine the elastic moduli of rock cores and modulus values are not much utilized in design practice. The reason seems to result from the general perception that values obtained by dynamic measurement are much higher (about 10 times) than those determined statically. This paper presents results from dynamic and static tests on rock cores. The findings are : 1) elastic moduli can be consistently determined by laboratory seismic testing. 2) nonlear deformation characteristic of rock cores was tentatively proposed with variation in elastic modulus with strain.

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Measurement of Dynamic Compressive Properties of Apples using the Oscillatory Test

  • Lee, Jong-Whan;Tan, Jinglu;Waluyo, Sri
    • Journal of Biosystems Engineering
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    • v.37 no.1
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    • pp.28-35
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    • 2012
  • Purpose: This study performed the oscillatory test using the texture analyzer to characterize the viscoelastic behavior of apples such as the storage modulus (E'), the loss modulus (E"), the complex modulus (${\mid}E^*{\mid}$) and the energy dissipated per cycle ($W_{diss}$). Methods: The sinusoidal deformation with the frequency of 1-10 Hz and the maximum displacement of 0.1 mm were applied to the flesh tissues of Fuji, Golden Delicious and Red Delicious apples. The Lissajous figure was used to measure the phase angle(${\delta}$) between stress and strain curve. Results: Trigger force was critical to the measurement of the phase angle. E', E", ${\mid}E^*{\mid}$ and Wdiss were measured using the Lissajous figure and the phase angle. The complex modulus of Golden Delicious apple was significantly lower than those of Fuji apple and Red Delicious apple. Conclusions: Apple flesh was exhibiting more elasticity at low frequency, and more viscosity at high frequency. Dynamic compressive properties of Fuji apple were similar to those of Red Delicious apple but significantly different from those of Golden Delicious apple.

Analysis Method Considering the Ground Reinforcement Effect of Micropile by Field Loading Tests (재하시험을 통한 소구경말뚝의 지반보강효과를 고려한 해석법)

  • Hong, Seok-Woo
    • Journal of the Korean Geotechnical Society
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    • v.25 no.1
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    • pp.89-99
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    • 2009
  • Compared to standard piling methods, micropile construction can be used in downtown areas since it generates less vibration and noise. Since it only causes less soil disturbance, it is commonly used as reinforcement to existing structures. In this study, a field wherein the bearing capacity and settlement of soil can not support the weight of the superstructure was selected and micropiles were implemented instead of ordinary piles. The deformation modulus of the micropile reinforced ground was determined and was directly reflected in the design. Loading testing was used to check whether or not the allowable bearing capacity satisfies the condition of the designed bearing capacity. The computed deformation modulus based from the test was used in the numerical analysis of soil to investigate the stability of the foundation and analysis method. And a method for controlling the bearing capacity and settlement was recommended.

Suggestion for the improvement of the field measurements on the shotcrete lining (터널 숏크리트 계측의 개선방안)

  • Kim, Hak-Joon;Park, Si-Hyun;Bae, Gyu-Jin
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.12 no.2
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    • pp.177-192
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    • 2010
  • The field measurements on the shotcrete lining are usually performed during the tunnel construction. However, the credibility of the measurements is not certain because of the non-stress related strains occurring in the shotcrete, the uncertainty of the deformation modulus of the shotcrete, and the intrinsic difficulties involved in the strain measurements in the shotcrete. The problem related to the field measurements on the shotcrete is investigated using the review of the previous studies and the field measurement performed for this study. A method for the correction of stress measurements at the shotcrete lining, considering the non-stress related strains, is suggested using the literature review and the actual measurements obtained from the non-stress shotcretes. The deformation modulus used for the calculation of the stress acting on the shotcrete is also suggested.

Strain-dependent-deformation property of Gyeongju compacted bentonite buffer material for engineered barrier system

  • Ivan Jeff Navea;Jebie Balagosa;Seok Yoon;Yun Wook Choo
    • Nuclear Engineering and Technology
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    • v.56 no.5
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    • pp.1854-1862
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    • 2024
  • This study aims to investigate the strain-dependent-deformation property of Gyeongju bentonite buffer material. A series of unconfined compressive tests were performed with cylindrical specimens prepared at varying dry densities (𝜌d = 1.58 g/cm3 to 1.74 g/cm3) using cold isostatic pressing technique. It is found that as 𝜌d increase, the unconfined compressive strength (qu), failure strain, and elastic modulus (E) of Gyeongju compacted bentonite (GCB) increases. Normalized elastic modulus (Esec/Emax) degradation curves of GCB specimens are fitted using Ramberg-Osgood model and the elastic threshold strain (𝜀e,th) is determined through the fitted curves. The strain-dependency of E and Poisson's ratio (v) of GCB were observed. E and v were measured constant below 𝜀e,th of 0.14 %. Then, E decreases while v increases after exceeding the strain threshold. The Esec/Emax degradation curves of GCB in this study suggests wider linear range and higher linearity than those of sedimentary clay in previous study. On top of that, the influence of 𝜌d is observed on Esec/Emax degradation curves of GCB, showing a slight increase in 𝜀e,th with increase in 𝜌d. Furthermore, an empirical model of qu with 𝜌d and a correlation model between qu and E are proposed for Gyeongju bentonite buffer materials.

Study on the Rheological Properties and Effects of Tannin components of Acorn Starch Gel (도토리 전분 묵의 Rheology 특성과 Tannin성분의 영향에 대하여)

  • 구성자
    • Journal of the Korean Home Economics Association
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    • v.23 no.1
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    • pp.33-47
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    • 1985
  • The rheological properties of acorn starch gel were investigated in region of small and large deformation. The properties were compared with those of potato and wheat starch gel. On the physical characteristics and the effect of tannin contents of acorn starch were examined. RESULTS : 1. X-ray diffractogram of acorn starch showed C-type and its granules swelled gradully with heating. 2. Hardness, brittleness and both small and large deformation of the acorn starch gel were remarkably large, also the concentration dependence of the acorn starch gel could be recognized in small deformation and hardness. 3. The Young's modulus of Hookean body in small deformation and the rupture stress in large deformation differed obviously from the parameters of rheological properties in various gels. 4. It was found that the selling power, viscosity and rhelogical properties were affected obviously by the tannin.

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Effects of Initial Stress on the Deformation of Sand (초기응력상태(初期應力狀態)가 모래의 변형(變形)에 미치는 영향(影響))

  • Kang, Byung Hee;Chung, In Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.3 no.1
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    • pp.65-72
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    • 1983
  • Dry sand specimens for both normally consolidated and overconsolidated triaxial compression tests were prestressed on the path with five different coefficients of earth pressure 1.0, 3/4, 0.55, $K_0$ and 1/3. Deformation resistance of normally consolidated sand increased with increasing the initial stress for all coefficients of earth pressure during consolidation, and the deformation modulus at a certain initial stress showed a tendency to increase with increasing the coefficient of earth pressure. And deformation moduli($E_i$, $E_{50}$), were found to be proportional to the $n_{th}$ power of initial stresses[${\sigma}_{m0}{^{\prime}}$, ${\sigma}_{10}{^{\prime}}$, ${\sigma}_{30}{^{\prime}}$, $({\sigma}_1-{\sigma}_3)_0$] for both isotropically and anisotropically normally consolidated samples, where n varied from 0.37 to 0.92. Overconsolidated sand with the higher overconsolidation ratio showed the higher deformation modulus. It is concluded that the $K_0$-anisotropically consolidated triaxial compression test is necessary to obtain the more accurate value of in-situ deformation modulus.

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Estimation of Deformation Modulus of Basaltic Rock Masses in Northeastern and Northwestern Jeju Island (제주도 북동부 및 북서부 현무암반의 변형계수 추정)

  • Yang, Soon-Bo;Boo, Sang-Pil
    • Journal of the Korean Geotechnical Society
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    • v.35 no.1
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    • pp.5-15
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    • 2019
  • In this study, the in situ deformation moduli, which were measured by borehole loading tests at basaltic rock masses located in the northeastern onshore and offshore and the northwestern onshore of Jeju Island, were examined in relation to RQD and RMR. The measured deformation moduli were also compared with the estimated deformation moduli from conventional empirical formulas using RQD and RMR. In addition, the measured deformation moduli were analyzed with respect to both the velocity ratio ($V_P/V_S$) and dynamic Poisson's ratio, which were obtained from the elastic wave velocities measured by velocity logging tests. As results, with only RQD, it was inappropriate to evaluate the quality of the Jeju island basaltic rock masses, which are characterized by vesicular structures, to select a measurement method of in situ deformation moduli, and to estimate the deformation moduli. On the other hand, it was desirable to evaluate the quality of the Jeju Island basaltic rock masses, and to estimate the deformation moduli by using RMR. The conventional empirical formulas using RMR overestimated the deformation moduli of the Jeju Island basaltic rock masses. There was qualitative consistency in the relation between velocity ratio and deformation moduli. To estimate appropriately the deformation moduli of the Jeju Island basaltic rock masses, empirical formulas were proposed as the function of RMR and velocity ratio, respectively.