• Journal of the Korean Geotechnical Society
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• v.25 no.2
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• pp.67-77
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• 2009

In this study, the relations of cone tip resistances (qc) and DMT indices of cemented sand are analyzed from a series of calibration chamber tests. The experimental results show that, with increasing the cementation level, three DMT indices also increase. The CPT and DMT do not appear to properly reflect the cementation effect of sand, since the penetration induces the damage of cementation. Nevertheless, the DMT is more sensitive to deformation characteristics of cemented sand than CPT. It is also observed that the $E_D/q_c$ ratio of cemented sand is larger than that of uncemented sand. However, the $K_D-q_c/{\sigma}_v'$ relation is independant of cementation, unlike the result of previous study. In addition, this study evaluates the constrained modulus and cohesion intercept of cemented sand using the relation between cone resistance and dilatometer constrained modulus ($M_D$).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4C
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• pp.193-200
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• 2010

This study suggests a method predicting at-rest coefficient of earth pressure ($K_0$) in order to evaluate the effect of stress history of granular soil. The method is based on the relation $K_D/K_0={\chi}(E_D/{\sigma}_m{^{\prime}})^{\delta}$, which is developed by combining two previously published relations such as $E_D/{\sigma}_m{^{\prime}}-{\psi}$ and $K_D/K_0-{\psi}$. As $K_D$ and $E_D$ are observed to be sensitive to the pre-stress, both indices are adopted for the estimation of $K_0$ value of granular soil. It is shown that the proposed $K_D/K_0-E_D/{\sigma}_m{^{\prime}}$ relation is insignificantly affected by the stress history. It is concluded from the comparative study that the proposed method, which uses only dilatometer test results to predict the $K_0$ of granular soil, provides more convenient and reliable prediction than other methods which use both CPT and DMT results.

• Journal of the Korean Geotechnical Society
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• v.26 no.7
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• pp.7-16
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• 2010

Stress history increases the residual horizontal stress of granular soil and, consequently, the penetration resistance. This study analyzes the effect of stress history on the cone resistance ($q_c$), horizontal stress index ($K_D$) and dilatometer modulus ($E_D$) of CPT and DMT from calibration chamber specimen in OC as well as NC state. Test results show that the normalized cone resistance by mean effective stress correlates well with the relative density and the state parameter, whereas the normalized cone resistance by vertical effective stress is a little affected by stress history. The influence of stress history is more reflected on $K_D$ than $E_D$ and $q_c$. The $K_D/K_0$, in which the effect of stress history on $K_D$ is compensated by the at-rest coefficient of earth pressure, $K_0$, is related to relative density, state parameter and the normalized cone resistance by mean effective stress. It is also observed that the normalized dilatometer modulus by mean effective stress ($E_D/{\sigma}_m'$) shows a unique correlation with the state parameter, regardless of stress history.

• Journal of the Korean Geotechnical Society
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• v.24 no.1
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• pp.91-99
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• 2008

The method to prepare the large cemented sand specimen for calibration chamber test by air-pluviation is investigated in this study. The uniformity of cemented specimen is evaluated by performing the CPTs, DMTs, and bender element tests in the calibration chamber. The sand particles, pre-wetted with 0.5% water content, are mixed with gypsum to provide the homogeneous coating of gypsum particles on the grain surface. It was shown that the pre-wetting of particle surface is effective to minimize the potential for segregation between sands and gypsum during air-pluviation. It was observed that the extreme void ratios ($e_{max}\;and\;e_{mix}$) of the mixture of pre-wetted sand and gypsum powder increase at lower gypsum content while those of the mixture of dry sand and gypsum decrease with increasing gypsum content. It was also shown from the test results that large cemented specimens reconstituted in calibration chamber by rainer system are quite uniform in vertical and horizontal directions.

• Journal of the Korean Geotechnical Society
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• v.26 no.4
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• pp.27-36
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• 2010

In this study, a series of flat dilatometer tests are performed for Busan sand reconstituted in a large calibration chamber to evaluate the state parameter ($\Psi$). Experimental result shows that the horizontal amplification factor ($K_D/K_0$) is linearly related with state parameter in semi-logarithmic space, but the $K_D/K_0$ of OC specimen is smaller than that of NC specimen because of the horizontal residual stress by stress history of OC specimen. The relation between the normalized dilatometer modulus ($E_D/\sigma_m'$) and the state parameter is also linearly expressed in semi-logarithmic space, and the effect of stress history is relatively insignificant in this relation. However, the variation in $E_D/\sigma_m'-\Psi$ relation of NC state is slightly higher than that of OC state due to the effect of the stress level, and the correlation curve is descending with increase of confining stress. The comparison of test result with previous results of Ticino and Toyoura sands shows that the $E_D/\sigma_m'-\Psi$ relation of Toyoura sand is located on upper side than that of Busan and Tieino sands due to the effect of the higher compressibility, whereas the $K_D/K_0-\Psi$ relation of each sand is irregularly distributed.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.677-684
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• 2000

Piezocone test as well as Dilatometer tests are used worldwide to evaluate the engineering properties of clay soils. The common strong point of the two tests is that they can estimate, by the identical test equipment, various properties of soils, which are the unit weight of soils of OCR, K$\sub$o/, undrained shear strength(s$\sub$u/), coefficient of consolidation(c$\sub$h/) and soil classification etc,. A series of the two types of field tests are performed in this study on marine clays with low plasticity at Inchon International Airport construction site to estimate various properties of the soils such as s$\sub$u/, OCR, and c$\sub$h/, which are then compared each other as well as with the results of reference tests. The comparisons show that the way of interpretation is the most critical factor in obtaining confidential results for a certain engineering property for both tests.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.241-252
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• 2010

This study investigates the application of dilatometer test for evaluating the deformation characteristics of granular soil. $K_D$ is the most sensitive to the stress history among CPT and DMT measurements, and $E_D$ and $q_c$ are observed to be similarly affected by the stress history. The coefficient of at-rest earth pressure($K_0$) is an indirect measure evaluating the stress history of granular soil. A relation using only DMT indices provides appropriate prediction of $K_0$ values. Although penetration of dilatometer inevitably induces the failure of cementation bonds, $E_D$ reflects the deformation characteristics of undamaged cementation relatively well. Therefore, a slightly better prediction of M value for cemented sand is achieved by using $E_D$ rather than $q_c$. Because of the weaker particle strength of calcareous sand compared than quartz sand, the majority of sand particles adjacent to dilatometer probe will be crushed during penetration. The particle crushing will induce the less contraction of the dilatometer membrane during penetration, consequently, the smaller $K_D$ and $E_D$ of calcareous sand.

• Journal of Powder Materials
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• v.21 no.2
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• pp.102-107
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• 2014

A high temperature dilatometer attached to a graphite furnace is built and used to study the sintering behavior of $B_4C$. Pristine and carbon doped $B_4C$ compacts are sintered at various soaking temperatures and their shrinkage profiles are detected simultaneously using the dilatometer. Carbon additions enhance the sinterability of $B_4C$ with sintering to more than 97% of the theoretical density, while pristine $B_4C$ compacts could not be sintered above 91% due to particle coarsening. The shrinkage profiles of $B_4C$ reveal that the effect of carbon on the sinterability of $B_4C$ can be seen mostly below $1950^{\circ}C$. The high temperature dilatometer delivers very useful information which is impossible to obtain with conventional furnaces.

• Journal of the Korean Geotechnical Society
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• v.27 no.4
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• pp.21-32
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• 2011

A series of in-situ and laboratory tests were performed for the clayey soils of Busan area in order to develop the methods to evaluate the compressibility using CPT and DMT results. The laboratory tests show that the clayey layers of Busan areas are normally consolidated, and their compression indices are turned out to be 0.5~1.3. From the analysis of test results, correlation factors between the cone resistance and constrained modulus (${\alpha}_m$ and ${\alpha}_n$) are observed to decrease with increasing plasticity index, and the correlation factor between the dilatometer modulus and constrained modulus $(R_M)$ increases with $1/I_D$. Based on these relationships, the methods evaluating the constrained modulus from CPT and DMT results are suggested. It is shown that the prediction method by CPT underestimates the constrained modulus of improved ground, whereas the prediction method by DMT is suitable for evaluating the constrained modulus of improved and unimproved ground.

• Journal of the Korean Applied Science and Technology
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• v.35 no.2
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• pp.472-477
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• 2018

The excess molar volumes of a general anesthetics on Purple membrane and Red membrane separated by extraction in Halobacteriun Halobium and in suspensions of vesicle have been determined at $25^{\circ}C$, it was used a excess volume dilatometer. The anesthesia characteristics of general anesthetics, Propofol was fined by our study to correlate with excess molar volume. Excess volume changes of the vesicle measured by excess volume dilatometer, which is an important amino acid and lipid in the purple membrane and red membrane by means of specific weight in Halobacteriun Halobium, were studied by absorption intensity at 280 nm and 330 nm. The particle size analysis and relative turbidity of Purple membrane and Red membrane by means of Propofol were measured for mechanical properties. In the samples where Propofol is incoporated in vesicle, especially, the excess molar volume of PM + RM + Propofol is the greatest than the excess molar volumes of PM, and RM.