21 research outputs found
The continuum approach in a grouting model
Отримано значення максимального розміру пори, при якому континуальний підхід все ще можна застосовувати в моделюванні поширення цементу в насиченому піску під час цементації, що не руйнує структуру ґрунту.Получено значение максимального размера поры, при котором континуальный подход всё ещё можно применять в моделировании распространения цемента в насыщенном песке при цементации, которая не разрушает структуру грунта.The value of the maximal pore size whereby the continuum approach can still be adopted for modeling cement grout propagation in saturated sand during permeation grouting is obtained
A realization of the uncertainty uniformity principle in a grouting model
A method of a realization of the uncertainty uniformity principle in grouting model calculations is described.Описаний спосіб реалізації принципу рівномірності похибки в розрахунках згідно моделі нагнітання
A realization of the uncertainty uniformity principle in a grouting model
A method of a realization of the uncertainty uniformity principle in grouting model calculations is described.Описаний спосіб реалізації принципу рівномірності похибки в розрахунках згідно моделі нагнітання
Controlling suction by vapour equilibrium technique at different temperatures, application to the determination of the water retention properties of MX80 clay
Problems related to unsaturated soils are frequently encountered in
geotechnical or environmental engineering works. In most cases, for the purpose
of simplicity, the problems are studied by considering the suction effects on
volume change or shear strength under isothermal conditions. Under isothermal
condition, very often, a temperature independent water retention curve is
considered in the analysis, which is obviously a simplification. When the
temperature changes are too significant to be neglected, it is necessary to
account for the thermal effects. In this paper, a method for controlling
suction using the vapour equilibrium technique at different temperatures is
presented. First, calibration of various saturated saline solutions was carried
out from temperature of 20 degrees C to 60 degrees C. A mirror psychrometer was
used for the measurement of relative humidity generated by saturated saline
solutions at different temperatures. The results obtained are in good agreement
with the data from the literature. This information was then used to determine
the water retention properties of MX80 clay, which showed that the retention
curve is shifting down with increasing of temperature
Change of microstructure of clays due to the presence of heavy metal ions in pore water
The compressibility of engineered barrier clays is, to a large extent, controlled by microstructure change due to the presence of chemical ions in clay-water system. This paper aims to investigate the change of microstructure of clays due to the presence of heavy metal ions in pore water. We use two pure clays (kaolinite and bentonite) in the study. One-dimensional consolidation tests were performed on reconstituted samples, which are prepared with distilled water and three types of heavy metal solutions (Pb(NO3)2, Cu(NO3)2, Zn(NO3)2,). In order to better understand the impact of chemical pore fluid on microstructure of the two clays, following the consolidation test, scanning electron microscope (SEM) observations and mercury intrusion pore size distribution measurements (MIP) were conducted. Due to the measurement range of MIP, which is only allowed to measure the minimal pore size 20 Å, BET method by gas sorption, whose measurement pore size range is from 3.5 Å to 500 Å, is used to measure the micropore size distribution. By this method, specific surface area of the soils can be also determined. It can be employed to demonstrate the difference of creep performance between the soils. Furthermore, a series of batch equilibrium tests were conducted to better understand the physical-chemical interactions between the particles of soils and the heavy metal ions. With the further consideration of the interparticle electrical attractive and repulsive force, an attempt has been made to predict the creep behaviour by using the modified Gouy-Chapman double layer theory. The results of calculation were compared with that of tests. The comparison shows that the prediction of compressibility of the clays according to the modified double diffuse layer theory can be reasonably agreement with the experimental data
Change of microstructure of clays due to the presence of heavy metal ions in pore water
The compressibility of engineered barrier clays is, to a large extent, controlled
by microstructure change due to the presence of chemical ions in clay-water
system. This paper aims to investigate the change of microstructure of clays due
to the presence of heavy metal ions in pore water. We use two pure clays
(kaolinite and bentonite) in the study. One-dimensional consolidation tests were
performed on reconstituted samples, which are prepared with distilled water and
three types of heavy metal solutions (Pb(NO3)2,
Cu(NO3)2, Zn(NO3)2,). In order
to better understand the impact of chemical pore fluid on microstructure of the
two clays, following the consolidation test, scanning electron microscope (SEM)
observations and mercury intrusion pore size distribution measurements (MIP)
were conducted. Due to the measurement range of MIP, which is only allowed to
measure the minimal pore size 20 Å, BET method by gas sorption, whose
measurement pore size range is from 3.5 Å to 500 Å, is used to measure the
micropore size distribution. By this method, specific surface area of the soils
can be also determined. It can be employed to demonstrate the difference of
creep performance between the soils. Furthermore, a series of batch equilibrium
tests were conducted to better understand the physical-chemical interactions
between the particles of soils and the heavy metal ions. With the further
consideration of the interparticle electrical attractive and repulsive force, an
attempt has been made to predict the creep behaviour by using the modified
Gouy-Chapman double layer theory. The results of calculation were compared with
that of tests. The comparison shows that the prediction of compressibility of
the clays according to the modified double diffuse layer theory can be
reasonably agreement with the experimental data
Study of the effect of flax fibers on the fracture behavior of earth concrete by simultaneous application of digital image correlation and acoustic emission
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