Discussion of “Quality of Conventional Fixed Piston Samplers of Norwegian Soft Clay” by Michael Long, Nouri El Hadj, and Knut Hagberg

2010 ◽  
Vol 136 (4) ◽  
pp. 649-650
Author(s):  
R. D. Holtz
Keyword(s):  
Soft Clay

scholarly journals Quality of Conventional Fixed Piston Samples of Norwegian Soft Clay

2009 ◽  
Vol 135 (2) ◽  
pp. 185-198 ◽  
Author(s):  
Michael Long ◽  
Nouri El Hadj ◽  
Knut Hagberg
Keyword(s):  
Soft Clay

Study of “Wave Type” Uneven Settlement and Reinforcing Method of Soft Clay Foundation

2011 ◽  
Vol 243-249 ◽  
pp. 2990-2996
Author(s):  
Li Qiang Sun ◽  
Shu Wang Yan ◽  
Hong Juan He ◽  
Yu Xu
Keyword(s):  
Soft Soil ◽  
Soft Clay ◽  
Traffic Load ◽  
Dominant Factor ◽  
Wave Type ◽  
The Road ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Preloading Method

The deformation is the dominant factor of the quality of the road constructed on the soft soil foundation. Tianjin DongJiang port is located on the hydraulic filled soil foundation which is improved by using vacuum preloading method. Roads in this area often suffer wave type asymmetry settlement, which serious affects the usage of the road and causes damage to both vehicles and human being. It is found that the initial wave asymmetry deformation of the road on very soft soil foundation usually exists and will be developing continuously under the traffic load. The mechanism of the wavy failure of the road is discussed by establishing a mechanical model. The method of using geogrids to reduce the asymmetry deformation is proposed, the reinforce effect is analyzed using finite element method.

scholarly journals Characterization of physical, chemical and microstructure properties in the soft clay soil of the paddy field area

2021 ◽  
Vol 18 (1) ◽  
pp. 81
Author(s):  
Muhammad Rendana ◽  
Wan Mohd Razi Idris ◽  
Sahibin Abdul Rahim ◽  
Zulfahmi Ali Rahman ◽  
Tukimat Lihan
Keyword(s):  
Paddy Field ◽  
Clay Soil ◽  
Soil Aggregates ◽  
Soft Clay ◽  
Chemical Properties ◽  
Silty Clay ◽  
Physical Chemical ◽  
Physical And Chemical ◽  
Field Area

<p>The soft clay soil has been categorized as infertile soil. The occurrence of soft clay soil in paddy field areas can decline soil quality and rice production. Therefore, to find the best technique for amending this soil, this study aimed to analyze the physical, chemical, and microstructure properties of the soft clay soil in the paddy field area. The soft clay soil samples were collected from two paddy blocks in Kedah, Malaysia. The physical and chemical properties of the soil were determined using the standard method in the laboratory. The microstructure properties were analyzed using Zeiss SUPRA 55VP microscopes. The results found that the soft clay soil was composed of silt – clay (&gt; 90%) with the texture of silty clay. The soft clay soil was characterized by low values of organic matter (2.63-3.42%), pH (3.32-3.69), cation exchange capacity (6.89-8.72 cmol<sub>c</sub> kg<sup>-1</sup>), available P (0.14-0.41 mg kg<sup>-1</sup>), aggregate stability (16.53-17.78%), and hydraulic conductivity (0.17 cm hr<sup>-1</sup>). In contrast, it indicated high values of soil water content (42.24-43.21%), and exchangeable Na<sup>+</sup> ions (2.48-2.50 cmol<sub>c</sub> kg<sup>-1</sup>). In addition, the analysis of heavy metals content revealed that their concentrations were below the critical level in the soil. The soft clay soil was largely governed by kaolinite minerals, and it had less compact structures with many large voids among soil aggregates. In conclusion, the quality of soft clay soil in the study area was poor with low physical and chemical parameters. The quality of the soil could be improved by the addition of soil amendments such as zeolite, cement, and other additive materials to absorb the excess water in the soil and increase the soil strength.</p>

Comparison of Field Performance between Bamboo-Geotextile Composite Embankment and High Strength Geotextile Embankment

2012 ◽  
Vol 587 ◽  
pp. 77-80
Author(s):  
Aminaton Marto ◽  
Bakhtiar Affandy Othman ◽  
Fauziah Kasim ◽  
Ismail Bakar
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Clay ◽  
Field Performance ◽  
High Strength ◽  
Foundation Soil ◽  
Excess Pore Water Pressure ◽  
Excess Pore

Trial embankment approximately 3 meters height, 10 meters of length, 16 meters width, and a slope of 1V: 2H was completed on soft clay site at RECESS, UTHM, Batu Pahat, Johor, Malaysia. Two embankments were respectively reinforced by a high strength geotextile (HSG) and the combination of bamboo and low strength geotextile or bamboo-geotextile composite (BGC) at the interface between embankment fill and foundation soil. Each embankment was installed with the same geotechnical instrumentation scheme for monitoring purposes. The purpose of this paper is to analyse the field performance for both embankments in terms of improving settlement embankment under the embankment. For this purpose, the settlement under the embankment, settlement at the surface of the embankment and the excess pore water pressure response were measured through geotechnical instrumentation for over 418 days. The results showed that the BGC system is more practical than HSG in terms of settlement and also in terms of cost, without compromising the quality of the embankment performance.

An Oedometer-Based Method for Preparing Reconstituted Clay Samples

2015 ◽  
Vol 719-720 ◽  
pp. 193-196
Author(s):  
Jie Yin ◽  
Yong Hong Miao
Keyword(s):  
Mechanical Behavior ◽  
Soil Structure ◽  
Large Diameter ◽  
Soft Clay ◽  
Soil Samples ◽  
Improved Method ◽  
Structured Soils ◽  
Reconstituted Soil ◽  
Natural Clays

It is well known that the mechanical behavior of the natural intact soft clay is usually quite different from that of the reconstituted counterpart. Hence, how to predict the influences of soil structure on the mechanical behavior of natural clays is an important issue in geotechnical engineering.The mechanical behavior of structured soils can usually be quantitatively assessed based on the mechanical behavior obtained from corresponding reconstituted clays. The preparing method for reconstituted soils will affect the quality of reconstituted samples greatly, and therefore, affect their mechanical parameter. To guarantee the quality of reconstituted soil samples, a large diameter oedometer apparatus is developed. Also, an oedomer-based method for preparing reconstituted clay samples is proposed. Typical soft Lianyungang city clay from China is chosen to testify the methods and corresponding procedures. The feasibility of the improved method is confirmed by comparing its results with those of the normal oedometer test.

scholarly journals Evaluation of sample quality from different sampling methods in Finnish soft sensitive clays

2019 ◽  
Vol 56 (8) ◽  
pp. 1154-1168 ◽  
Author(s):  
Bruno Di Buò ◽  
Juha Selänpää ◽  
Tim Tapani Länsivaara ◽  
Marco D’Ignazio
Keyword(s):  
Storage Time ◽  
Soft Clay ◽  
Test Results ◽  
Geotechnical Parameters ◽  
Sample Quality ◽  
Constant Rate ◽  
And Performance

The determination of reliable geotechnical parameters from laboratory testing is highly dependent on sample quality. Over the past decades, undisturbed sampling of soft sensitive clays has been performed using various apparatuses and procedures. This paper outlines details of the design and performance of a new Laval-type tube sampler employed for the investigation of five soft clay sites located in Finland. The investigation was conducted using the new tube sampler and two different piston samplers. The sample quality was evaluated based on the recompression volume during reconsolidation to the in situ effective stress in constant-rate-of-strain oedometer tests. Test results show that tube samples are generally characterized by higher quality, especially in low-plasticity clays. In particular, the quality of piston samples is highly affected by the apparatus condition and sampling operations. Furthermore, the influence of storage time on tube samples was investigated. To guarantee a proper confinement, and thus reduce swelling, a pressurized system was applied to the tube samples obtained in two soft clay sites. Results demonstrate that the sample quality is not significantly affected by storage time as long as the soil is properly stored in the tube.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

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