In situ determination of creep properties of sea ice with the pressuremeter

1989 ◽  
Vol 26 (4) ◽  
pp. 575-594 ◽  
Author(s):  
J. R. Murat ◽  
B. Ladanyi ◽  
P. Huneault
Keyword(s):  
Sea Ice ◽  
Data Acquisition System ◽  
Data Interpretation ◽  
Stress Redistribution ◽  
In Situ Testing ◽  
Creep Properties ◽  
New Procedures ◽  
Proper Consideration

A series of pressuremeter creep and relaxation tests was carried out in the spring of 1987 in a sea-ice cover at Igloolik, Northwest Territories, for the purpose of testing some new procedures for in situ determination of creep properties of sea ice. Compared with a similar field study carried out 9 years earlier, the present investigation included some clear improvements, not only in the instrumentation and data acquisition system but also in the data interpretation and processing. In particular, it is shown that consistent values of creep parameters can be obtained only if proper consideration is made of the amount of stress redistribution taking place before and during each new load application. Key words: in situ testing, pressuremeter, sea ice, creep properties, stress redistribution.

Quantitative determination of tip undercooling of faceted sea ice with in situ experiments

2021 ◽  
Author(s):  
Tongxin Zhang ◽  
Zhijun Wang ◽  
Lilin Wang ◽  
Junjie Li ◽  
Jincheng Wang
Keyword(s):  
Sea Ice ◽  
Quantitative Determination ◽  
In Situ Experiments

Borehole penetration and expansion devices for ice testing

1996 ◽  
Vol 23 (1) ◽  
pp. 157-164 ◽  
Author(s):  
Branko Ladanyi
Keyword(s):  
Special Kind ◽  
Strength Properties ◽  
Theoretical Interpretation ◽  
In Situ Testing ◽  
Cone Penetration ◽  
Creep Properties ◽  
Pilot Hole ◽  
Expansion Test ◽  
Sharp Cone

The paper presents two methods for in situ testing of strength and creep properties of ice, together with their theoretical interpretation and typical results. The two methods which are relatively new in this area of application, are the stress-controlled cone penetration test (CPT), and the sharp cone test (SCT). The CPT has been shown in the last few years to be an excellent tool for both ice quality profiling and ice creep and strength properties determination. The test can be used for penetrating vertically through an ice sheet, or laterally into an ice wall in a trench. The SCT is a special kind of borehole-expansion test. The method consists in pushing a smooth, low-angle, conical indentor into a predrilled conical portion of a borehole, which ends with a smaller diameter pilot hole. The creep properties of ice are then deduced from the relationship between the applied load, time, and cone penetration, which is directly related to the hole expansion. Key words: ice, creep, strength, in situ testing, cone penetration, borehole expansion, sharp cone.

Pénétromètre à chute libre: Impact et pénétration dans des argiles reconstituées

1985 ◽  
Vol 22 (1) ◽  
pp. 129-135 ◽  
Author(s):  
D. Levacher
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Key Words ◽  
Laboratory Tests ◽  
Free Fall ◽  
Test Series ◽  
Dynamic Resistance ◽  
In Situ Testing

The use of a free-fall penetrometer for the determination of the in situ mechanical properties of reconstituted clays is presented. The penetrometer is equipped with an accelerometer for measuring continuously the acceleration or the deceleration. The equipment is relatively simple and the test is fast. The usefulness of such a test is demonstrated, and its adaptation to in situ testing is easy to achieve. Laboratory tests indicate that the shear strength can be directly computed as a function of depth. The penetrometer, as developed, can reach a depth of 0.50 m, but it is possible to achieve greater depths with some modifications. The results presented pertain to a few test series on reconstituted clays, with impact velocities up to 8 m/s. Key words: penetrometer, impact, reconstituted clays, tests, dynamic resistance, cohesion. [Journal translation]

scholarly journals First “in situ” determination of gas transport coefficients ( DO2, DAr, and DN2) from bulk gas concentration measurements (O2, N2, Ar) in natural sea ice

2014 ◽  
Vol 119 (10) ◽  
pp. 6655-6668 ◽  
Author(s):  
Odile Crabeck ◽  
B. Delille ◽  
S. Rysgaard ◽  
D. N. Thomas ◽  
N.-X. Geilfus ◽  
...  
Keyword(s):  
Sea Ice ◽  
Gas Transport ◽  
Transport Coefficients ◽  
Gas Concentration ◽  
Concentration Measurements

Sharp cone testing of creep properties of frozen sand

1992 ◽  
Vol 29 (5) ◽  
pp. 757-764 ◽  
Author(s):  
B. Ladanyi ◽  
J. Sgaoula
Keyword(s):  
Field Testing ◽  
Frozen Soil ◽  
Theoretical Interpretation ◽  
Creep Properties ◽  
Frozen Sand ◽  
Cone Field ◽  
Sharp Cone ◽  
Constant Axial Load

The paper describes a new field testing method, called the sharp cone test, intended for in situ determination of creep properties of frozen soils and ice. The method consists of pushing a smooth, low-angle, cone into a predrilled conical portion of a borehole. The creep properties of the material are determined by applying a constant axial load on the cone, and by observing its time-dependent axial displacement as it penetrates and enlarges the conical hole. The paper describes the test, gives its theoretical interpretation, and shows the results of a series of tests carried out in a frozen sand. Key words : frozen soil, ice, sharp cone, field testing, creep properties.

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

Sign in / Sign up

Export Citation Format

Share Document