A New Approach to Predict the Strength Criterion of Frozen Soils Based on Micromechanical Framework

2019 ◽  
Author(s):  
De Zhang ◽  
Enlong Liu
Keyword(s):  
Strength Criterion ◽  
Frozen Soils ◽  
New Approach

Measuring total volumetric strains during triaxial tests on frozen soils: a new approach

1978 ◽  
Vol 15 (1) ◽  
pp. 47-53 ◽  
Author(s):  
M. J. O'Connor ◽  
R. J. Mitchell
Keyword(s):  
Volume Change ◽  
Deformation Rate ◽  
Sample Volume ◽  
Triaxial Tests ◽  
Fluid Level ◽  
Frozen Soils ◽  
New Approach ◽  
Triaxial Cell ◽  
Rate Controlled ◽  
Theoretical Accuracy

A triaxial cell has been modified to permit measurement of volumetric strains during deformation-rate-controlled and stress-controlled triaxial tests on frozen soils. In the system described here, a volume change in the soil sample alters the level of fluid in the triaxial cell. The fluid level can be monitored during the test using a sloping tube volumeter. Theoretical accuracy with this arrangement can exceed 0.1% of the sample volume.

scholarly journals A Nonlinear Strength Criterion for Frozen Sulfate Saline Silty Clay with Different Salt Contents

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yanhu Zhao ◽  
Yuanming Lai ◽  
Jing Zhang ◽  
Chong Wang
Keyword(s):  
Triaxial Compression ◽  
Strength Criterion ◽  
Experimental Results ◽  
Saline Soils ◽  
Silty Clay ◽  
Compression Tests ◽  
Frozen Soils ◽  
Conventional Triaxial Compression ◽  
Confining Pressures ◽  
Pressure Melting

It has been proven that the mechanical properties of frozen saline soils are different from frozen soils and unfrozen saline soils. In this paper, in order to study the effects of the salt contents on the strength characteristics of frozen soils, a series of conventional triaxial compression tests are carried out for frozen saline silty clay with Na2SO4 contents 0.0, 0.5, 1.5, and 2.5% under confining pressures from 0 MPa to 18 MPa at −6°C, respectively. The experimental results show that the strength of frozen saline silty clay presents obvious nonlinearity, the strength of frozen saline silty clay increases with increasing confining pressures at first, but with a further increase in confining pressures, the strength decreases because of pressure melting and crushing phenomena under high confining pressures, and salt contents have an important influence on strength of frozen saline silty clay. A strength criterion is proposed on the basis of the experimental results. The strength criterion could well reflect the nonlinear strength characteristic of frozen saline silty clay and the influence of salt contents on frozen saline silty clay.

A New Finite Fracture Mechanics Approach for Assessing the Strength of Bonded Lap Joints

2011 ◽  
Vol 471-472 ◽  
pp. 1075-1080 ◽  
Author(s):  
Philipp Weißgraeber ◽  
Wilfried Becker
Keyword(s):  
Fracture Mechanics ◽  
Energy Release ◽  
Optimization Problem ◽  
Strength Criterion ◽  
Lap Joints ◽  
Reliable Prediction ◽  
New Approach ◽  
Single Lap Joints ◽  
Finite Fracture Mechanics ◽  
Failure Loads

For the widespread use of adhesive joints an exact and reliable prediction of the strength is mandatory. In this work, a new approach to assess the strength of single lap joints is presented. The approach is based on the hybrid criterion as postulated by Leguillon in the framework of finite fracture mechanics. It strictly combines a consideration of an energy release balance and a fulfillment of a strength criterion. The present work is based on a simple model of the joint behavior and assumptions about crack initiation. From the stress distribution of the classical shear lag theory an incremental energy release rate is derived and is used to formulate the optimization problem of the failure load. The resulting predictions of critical failure loads are compared to experimental results of single lap joints. It is shown that the new approach is able to physically describe crack formation and the corresponding critical load within the framework and limitations of the underlying assumptions and simplifications. The work closes with a discussion of the limitations and an outlook on possible improvements of the underlying models and assumptions.

scholarly journals A new approach to modeling the behavior of frozen soils

2018 ◽  
Vol 246 ◽  
pp. 82-90 ◽  
Author(s):  
Ali Nassr ◽  
Mahzad Esmaeili-Falak ◽  
Hooshang Katebi ◽  
Akbar Javadi
Keyword(s):  
Frozen Soils ◽  
New Approach

The O–C diagrams of minor planets − a new approach to modelling the rotation

1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss
Keyword(s):  
Error Analysis ◽  
Time Dependence ◽  
Theoretical Work ◽  
Minor Planet ◽  
Minor Planets ◽  
New Approach ◽  
Preliminary Results ◽  
Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Processing Immunoperoxidase Labeled Cell Monolayers and Cryostat Sesctions For Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 714-715
Author(s):  
K. Chien ◽  
R. Van de Velde ◽  
I.P. Shintaku ◽  
A.F. Sassoon
Keyword(s):  
Cell Monolayer ◽  
Cell Types ◽  
Surface Antigens ◽  
Immunoperoxidase Method ◽  
Reaction Step ◽  
Hot Plate ◽  
Air Drying ◽  
New Approach ◽  
Cell Monolayers ◽  
Glass Slides

Immunoelectron microscopy of neoplastic lymphoma cells is valuable for precise localization of surface antigens and identification of cell types. We have developed a new approach in which the immunohistochemical staining can be evaluated prior to embedding for EM and desired area subsequently selected for ultrathin sectioning.A freshly prepared lymphoma cell suspension is spun onto polylysine hydrobromide- coated glass slides by cytocentrifugation and immediately fixed without air drying in polylysine paraformaldehyde (PLP) fixative. After rinsing in PBS, slides are stained by a 3-step immunoperoxidase method. Cell monolayer is then fixed in buffered 3% glutaraldehyde prior to DAB reaction. After the DAB reaction step, wet monolayers can be examined under LM for presence of brown reaction product and selected monolayers then processed by routine methods for EM and embedded with the Chien Re-embedding Mold. After the polymerization, the epoxy blocks are easily separated from the glass slides by heatingon a 100°C hot plate for 20 seconds.

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