Interpretation of field measurements for ice engineering applications

1996 ◽  
Vol 23 (1) ◽  
pp. 180-185
Author(s):  
Lorne W. Gold

A description is given of the nature of problems caused by ice for the engineer. Factors controlling the deformation behaviour and strength of ice are discussed briefly. A distinction is made between the behaviour of the relatively small volumes of competent ice that are normally used for tests and the large, inhomogeneous bodies that must be considered by the engineer. Consideration is given to the implications of this for the conduct of in situ tests and the interpretation of their results. Key words: ice, mechanical properties, mechanical behaviour, in situ testing, pressuremeter.

1985 ◽  
Vol 22 (1) ◽  
pp. 129-135 ◽  
Author(s):  
D. Levacher

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]


Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1131
Author(s):  
Soonkie Nam ◽  
Marte Gutierrez ◽  
Panayiotis Diplas ◽  
John Petrie

This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. Laboratory determination of hydraulic conductivity used the constant head permeability and oedometer tests on undisturbed Shelby tube and block soil samples. The auger hole method and Guelph permeameter tests were performed in the field. Groundwater table elevations in natural soil deposits with different hydraulic conductivity values were predicted using finite element seepage modeling and compared with field measurements to assess the various test results. Hydraulic conductivity values obtained by the auger hole method provide predictions that best match the groundwater table’s observed location at the field site. This observation indicates that hydraulic conductivity determined by the in situ test represents the actual conditions in the field better than that determined in a laboratory setting. The differences between the laboratory and in situ hydraulic conductivity values can be attributed to factors such as sample disturbance, soil anisotropy, fissures and cracks, and soil structure in addition to the conceptual and procedural differences in testing methods and effects of sample size.


1990 ◽  
Vol 27 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Mohammed G. Kabir ◽  
Alan J. Lutenegger

An investigation was conducted to demonstrate the applicability of cylindrical piezocone and flat piezoblade tests for providing reliable estimates of the coefficient of consolidation in clays. Coefficients of consolidation were calculated from piezocone dissipation tests for different degrees of consolidation using theoretical time factors to provide a comparison with laboratory oedometer tests. Three techniques were developed to calculate the coefficient of consolidation from piezoblade dissipation tests. Results from in situ pore pressure dissipation tests were compared with laboratory oedometer tests performed on undisturbed samples oriented in both the vertical and horizontal directions, to provide reference values of cv and ch. The results of investigations conducted at several clay sites are presented. Key words: in situ tests, piezocone, piezoblade, coefficient of consolidation, oedometer test, clays.


1995 ◽  
Vol 32 (3) ◽  
pp. 545-552 ◽  
Author(s):  
B. Wang ◽  
Hugh M. French

Field measurements of frozen soil creep in the upper 3.0 m of permafrost indicate that creep occurs in both winter and summer. Between 1992 and 1993, the mean rate of creep ranged from 0.44 cm at 1.6 m depth to 0.16 cm at 2.8 m depth but there was extreme variability. Creep parameters n and A, as defined by the power flow law, were calculated from field data. Parameter n ranged between 1.96 and 2.29 and increased with depth, while A decreased with depth. Comparisons of creep rates for different permafrost environments suggest that ground temperature largely controls the magnitude of permafrost creep. Key words : permafrost, creep parameters, Tibet Plateau.


1985 ◽  
Vol 22 (3) ◽  
pp. 298-307 ◽  
Author(s):  
J. M. O. Hughes ◽  
P. K. Robertson

An alternative approach to pressuremeter testing in sand, where the pressuremeter is pushed closed-ended, is discussed. Observations from cone penetration testing in sands are used to provide a theoretical background to the expected stress conditions around a full-displacement pressuremeter probe pushed into sand. The anticipated stress paths followed during the pressure expansion phase of the test are discussed. Data from both self-boring and full-displacement pressuremeter tests in sand are presented to support some of the suggested theoretical background. Key words: pressuremeter testing, in situ testing, sand.


2019 ◽  
Vol 92 ◽  
pp. 13006
Author(s):  
Eleni Stavropoulou ◽  
Christophe Dano ◽  
Marc Boulon

Since a few years, in France, the development and construction of offshore wind farms in different sites of the country is investigated. The wind turbines will be installed in soft carbonate rock formations (calcarenite, limestone), the mechanical properties of which can vary in a significant way according to the location of the site. Once installed, the bored piles will be sealed with grout in the hosting rock. It is well known that the mechanical behaviour of piles is mainly governed by the behaviour of the interface at the contact between the structure and the hosting rock. The study of the mechanical behaviour of these interfaces, being the weakest points in terms of mechanical resistance, is of great importance for the improvement of the design methods of such infrastructures. The shear response of the rock/grout interface is studied with laboratory experiments in the 3SR lab (Grenoble). The interface's mechanical properties are characterised by a series of shear tests under Constant Normal Stiffness (CNS), these conditions being the most representative of the in-situ conditions. Interface samples of a roughness representative of the in-situ drilling traces, are tested under different levels of applied normal stiffness. The shear response is studied for both monotonic and cyclic shear paths, while all tests are performed under wet conditions. The failure mechanisms are explored, taking into account the contrasting mechanical properties of the two materials composing the interface, as well as, the evolution of the geometrical profile of the interface. The correlation between roughness and the mechanical response of the interface is investigated and the importance of an existing roughness is discussed.


2013 ◽  
Vol 738-739 ◽  
pp. 338-343 ◽  
Author(s):  
Francisco Manuel Braz Fernandes ◽  
Karimbi Koosappa Mahesh ◽  
Corneliu Marius Crăciunescu ◽  
João Pedro Oliveira ◽  
Norbert Schell ◽  
...  

The demand of emerging joining techniques for shape memory alloys (SMA) has become of great importance, as their functional properties, namely shape memory effect (SME) and superelasticity (SE) present unique solutions for state-of-the-art applications. Literature shows that significant efforts have been conducted on laser welding of these alloys, although very limited results concerning mechanical properties are repeatedly achieved. A better understanding of the mechanical behaviour of these welded joints may be got through a detailed analysis of the structural characteristics of the material from the base metal to the weld bead. Such studies have been carried out on a series of Ni-rich Ni-Ti SMA laser welded plates using synchrotron radiation.


1996 ◽  
Vol 33 (1) ◽  
pp. 189-198 ◽  
Author(s):  
J A.R Ortigao ◽  
R P Cunha ◽  
L S Alves

An in situ testing programme was carried out in 1992 aimed at obtaining design parameters for the construction of the Brasília Underground line, Brazil. The top layer of soil consisted of an unsaturated and collapsible soft porous clay layer 5–30 m thick followed by residual soils from slate and interlayered metasiltsones and quartzites. A series of Marchetti dilatometer (DMT) logging tests results were comapred with Ménard pressuremeter (PMT) and horizontal plate loading (PLH) tests, as well as laboratory tests on block samples. In situ stresses, strength, and deformation parameters were obtained for the porous clay. The DMT yielded very good results: excellent repeatability, low cost, and results that agree with other in situ tests and laboratory data. Key words: porous clay, in situ testing, dilatometer, pressuremeter.


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