Experimental Study on Structural Properties Influencing on Compressibility of Soft Clay

2011 ◽  
Vol 261-263 ◽  
pp. 1767-1772
Author(s):  
Jiang Feng Wang ◽  
Yong Le Li ◽  
Yan Bin Gao ◽  
Zhi Quan Huang
Keyword(s):  
Yield Stress ◽  
Structural Properties ◽  
Soft Clay ◽  
Load Level ◽  
Horizontal Line ◽  
Undisturbed Soil ◽  
Straight Line ◽  
Undisturbed Samples ◽  
Reconstituted Soil ◽  
Compression Characteristics

Through the undisturbed samples and reconstituted samples for compression test, analyzed and got the characteristics of compression deformation and the influence law of structure properties on soft clay. The s-t curves deformation of reconstituted soil in small loads is the largest, as the load increases, tends gradually to horizontal line, but undisturbed soil deformation is the largest under the condition of a bigger load. Undisturbed soil due to structural exists, its s-lgt curves are divided into three categories according to load level. The e-lgp curve of soft clay is bounded by structure yield stress very clearly divided into two sections, but e-lgp curve of reconstituted soil is a straight line. Because structure of the reconstituted soil has been destroyed, its law of compression characteristics is comparative markedly. But due to the existence of undisturbed soil structural properties, near the structural yield stress, the compression parameters appear mutations. Research results show that influence of soft clay structural properties on its compression characteristics is not allowed to ignore.

Experimental Study on Structural Properties Influencing on Shear Strength of Soft Clay

2011 ◽  
Vol 243-249 ◽  
pp. 2487-2490
Author(s):  
Jiang Feng Wang ◽  
Yong Le Li ◽  
Yan Bin Gao ◽  
Yong Xiang Yang
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Shear Failure ◽  
Clayey Soil ◽  
Soft Clay ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Undisturbed Soil ◽  
Direct Shear Tests ◽  
Reconstituted Soil

The direct shear tests were conducted with undisturbed and reconstituted soft clay, then the structural influence on shear strength was studied, and the laws were got. No matter shear strength of slow shear or consolidated quick shear on undisturbed and reconstituted soil have not peak values, strength line of reconstituted soil is a slash, but the shear strength line of undisturbed soil is obviously a broken line. The internal friction angle of undisturbed and reconstituted soil is basically the same. There are good linear relationship between internal friction angle and plastic index of clayey soil. The amplitude of internal friction angle of reconstituted soil decreasing with plastic index increasing is less than that of undisturbed soil. From wf-lgp curve can be seen, with the increasing of vertical stress, water content of shear failure decrease gradually, and linear correlation of each curve is very good.

Study on the Shear Structural Yield of Soft Soil Affected by Drainage Condition

2012 ◽  
Vol 256-259 ◽  
pp. 416-421 ◽  
Author(s):  
Ai Wu Yang ◽  
Ling Wei Kong ◽  
Li Qiang Lu
Keyword(s):  
Yield Stress ◽  
Internal Structure ◽  
Structural Properties ◽  
Structural Characteristics ◽  
Soft Soil ◽  
Undisturbed Soil ◽  
Soil Particles ◽  
Axial Shear ◽  
The Impact

Four kinds of tri-axial shear structural yield stress is studied by controlling the pre-test consolidate degree and draining condition during the test. The results showed that draining condition influenced the tri-axial shear structural yield stress. When under the UU condition, structural characteristics appeared not clearly; when consolidated before testing and un-drained during test, only the undisturbed soil performed the structural yield stress; when draining during testing, the undisturbed soil showed the increased structural yield stress while the remolded soil could form certain structure. The impact of the draining condition on the structural characteristics is incurred by the change of the internal structure, which means that the draining condition have changed the arrangement and connection of the soil particles, then changed the soil structural properties.

Characterization of a smear zone around vertical drains by large-scale laboratory tests

2000 ◽  
Vol 37 (6) ◽  
pp. 1265-1271 ◽  
Author(s):  
J S Sharma ◽  
D Xiao
Keyword(s):  
Large Scale ◽  
Soft Clay ◽  
Excess Pore Pressure ◽  
Laboratory Model ◽  
Clay Layer ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
Undisturbed Samples ◽  
Oedometer Tests ◽  
Excess Pore

Installation of prefabricated vertical drains using a mandrel causes disturbance of clay surrounding the drain, resulting in a "smear" zone of reduced permeability. In this paper, an attempt is made to characterize the smear zone using large-scale laboratory model tests. Two tests, simulating the cases of "no smear" and "with smear," were conducted. Excess pore-water pressures were monitored at seven different locations along the radial direction. In addition, undisturbed samples were collected at various locations in the clay layer for conducting oedometer tests. The distribution of excess pore pressure due to drain installation gave a clear indication of the extent of the smear zone. The effect of reconsolidation on the properties of clay was found to be much greater than that of the remoulding of the clay. The extent of the smear zone was also confirmed from the change in permeability of the clay layer in the smear zone obtained from oedometer tests. The radius of the smear zone is about four times that of the mandrel, and the horizontal permeability of the clay layer in the smear zone is approximately 1.3 times smaller than that in the intact zone.Key words: consolidation, permeability, smear zone, soft clay, vertical drains.

Rheology and structure of blood suspensions

1964 ◽  
Vol 19 (1) ◽  
pp. 127-133 ◽  
Author(s):  
S. E. Charm ◽  
W. McComis ◽  
G. Kurland
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Yield Stress ◽  
Structural Model ◽  
Cell Suspensions ◽  
Rate Curve ◽  
Red Cell ◽  
Shear Rates ◽  
Straight Line ◽  
Rate Plot

A structural model developed for kaolin suspensions was applied to blood in order to determine the structure and strength of the red cell suspensions. The yield stress of red cell suspensions determined in settling experiments agreed with the yield stress determined from shear stress-shear rate information employing Casson's equation. Theoretical considerations indicate that the shear stress-shear rate curve for blood should approach a straight line. This was found to be true at shear rates above 40 sec-1. The slope of this line was predicted from calculations based on sedimentation experiments and a modified Einstein's equation. The data suggest that the curvature of the shear stress-shear rate plot at low shear rates is due to aggregates of cells which break down under increasing shear rate, resulting finally in individual flocs. It is suggested that a floc consists of one to four cells with adhering plasma. The aggregate was calculated to have twice as much plasma associated with it as does a floc. However, the size of the aggregate could not be determined since the number of flocs associated with an aggregate could not be determined. shear stress-shear rate curve; red cell floc; red cell aggregate; sedimentation rate; blood viscosity and flow Submitted on February 28, 1963

scholarly journals Calibration of a soil moisture sensor with disturbed and undisturbed soil samples from Bahia

2018 ◽  
Vol 22 (10) ◽  
pp. 696-701
Author(s):  
João G. A. Lima ◽  
Aureo S. de Oliveira ◽  
Luciano da S. Souza ◽  
Neilon D. da Silva ◽  
Paula C. Viana
Keyword(s):  
Soil Moisture ◽  
Soil Samples ◽  
Calibration Data ◽  
Undisturbed Soil ◽  
Moisture Sensor ◽  
Soil Moisture Sensor ◽  
Disturbed Soil ◽  
Undisturbed Samples ◽  
Three Samples ◽  
Quadratic Models

ABSTRACT The objective of this study was to evaluate the models proposed by manufacturers and in the literature with respect to soil moisture measurement and to evaluate the performance of the CS616 sensor in the calibration of disturbed and undisturbed soil samples. These calibrations were performed using linear and quadratic models. Disturbed samples were collected in São Gabriel/BA, six samples placed in pots, whereas undisturbed samples were collected in Cruz das Almas/BA, three samples directly collected in the area and placed in a container. A calibration was performed between 21/12/2016 and 08/01/2017. The models proposed in the literature and by manufacturers differed in the estimation of volumetric soil moisture. Disturbed soil samples had higher data dispersion than undisturbed samples, due to factors such as grain size and bulk density, which influence the calibration data. The CS616 sensor had satisfactory performance in the calibration of disturbed and undisturbed samples, with excellent fit of the soil moisture data. Using soil moisture contents obtained by the CS616 sensor, without a previous calibration, may lead to errors in the results, confirming the need for a specific calibration for each type of soil.

scholarly journals Relationship between mineral N content and N mineralization rate in disturbed and undisturbed soil samples incubated under field and laboratory conditions

Soil Research ◽  
1992 ◽  
Vol 30 (4) ◽  
pp. 477 ◽  
Author(s):  
J Sierra
Keyword(s):  
N Mineralization ◽  
Negative Relationship ◽  
Feedback Mechanism ◽  
Soil Samples ◽  
Mineralization Rate ◽  
Mineral N ◽  
Undisturbed Soil ◽  
N Content ◽  
Undisturbed Samples

An investigation of in situ N mineralization, using undisturbed soil samples, indicated a negative relationship between the mineral N content [(NO3+NH4)-N] at the beginning of the experiment and the mineral N produced during it. This suggests that a maximum value of mineral N accumulation in intact soil cores could be calculated from the relationship between mineral N content and N mineralization rate. This value would be related to the size of the mineralizable N pool. If this hypothesis is true, the amount of mineralizable N could be estimated from in situ incubations and utilized in the modelling of N mineralization in the field. The aim of this work was to verify this hypothesis. The relationship between the mineral N content and the N mineralization rate was analysed for in situ and laboratory incubations of disturbed and undisturbed soil samples. A negative relationship between the two variables was only obtained for the experiments carried out with undisturbed samples (in the field and laboratory incubations) when the soil moisture content was not limiting for N mineralization. Futhermore, in undisturbed samples, a negative relationship between mineralization rates of consecutive incubation periods was observed, i.e. the soil sample producing relatively more, during a given period, produced relatively less in the following period. This relationship suggests a feedback mechanism operating in N mineralization which would be related to a mineralization-immobilization process in soil microsites. Thus, the N mineralization pattern was more complex than that described by initial hypothesis. The possible consequence of this feedback mechanism on in situ N dynamics is discussed.

scholarly journals BENTUK PENYAJIAN SILEK KAPAK SEBAGAI BUDAYA TRADISI MASYARAKAT DI KANAGARIAN PADANG LAWEH KECAMATAN KOTO TUJUAH KABUPATEN SIJUNJUNG

2020 ◽  
Vol 10 (1) ◽  
pp. 148
Author(s):  
Chelina Dewi ◽  
Indrayuda Indrayuda
Keyword(s):  
Data Collection ◽  
Secondary Data ◽  
Primary Data ◽  
Cultural Tradition ◽  
Horizontal Line ◽  
Line Pattern ◽  
Data Presentation ◽  
Straight Line ◽  
Collection Data ◽  
Analyze Data

The research aims to reveal, describe and analyze about the Form of Presentation of Silek Axe as a Culture of Community Tradition in Kanagarian Padang Laweh District Koto Tujuah Sijunjung Regency. This type of research is qualitative research with descriptive methods of analysis. The data type uses primary data and secondary data. The main instruments are the researchers themselves and are assisted with supporting instruments such as stationery and cameras. Data collection techniques are conducted by way of literature, observation, interview and documentation. The steps to analyze data are data collection, data reduction, data presentation, and conclusion drawing. The results of this study show that Silek Kapak is a tradition of Padang Laweh people. Silek Axe was performed by 2 players, which was displayed in the courtyard of Rumah Gadang during the day. The form of presentation of Silek Axe in Kanagarian Padang Laweh Sub-District Koto Tujuah Sijunjung Regency is representative. Elements of Silek Axe Presentation Form as follows: (1) opening greeting motion, amuak kapalo, amuak dado, pata tobu, klotiak and closing greetings. (2) Silek Axe floor pattern uses a straight line pattern or horizontal line. (3) Silek Axe's accompanying music consists of: talempong, drums, gongs. (4) the costume used by the player in Silek Axe taluak balango in black, black pants, asamping and deta. (5) In addition, Silek Axe uses the Original Axe property as supporting silek axe show.Keywords: Form of Presentation, Silek Axe, Cultural Tradition

scholarly journals Compression behavior of reconstituted clay: A study on black clay

2018 ◽  
Vol 55 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Bhim Kumar Dahal ◽  
Jun-Jie Zheng
Keyword(s):  
Soil Sample ◽  
Void Ratio ◽  
Cement Content ◽  
Compression Index ◽  
Undisturbed Soil ◽  
Compression Behavior ◽  
Black Clay ◽  
Compression Behaviour ◽  
Remoulded Soil ◽  
Reconstituted Soil

 The soft and black clay found in the Kathmandu Valley is locally known as Kalomato which is highly compressible and weak. The Kalomato from the Khasibazaar is taken as study material. Experimental study is carried out on undisturbed, remoulded and reconstituted soil samples to determine the compression  behavior. The study revealed that the undisturbed soil sample has the highest compression  index among all samples while the remolded sample has the lowest compression index. The reconstituted soil sample using cement shows that the compression index increases with the increase in cement content while decrease with the increase in curing time. When cement content increases to 15%, the load required to compress the soil to the equal void ratio also increases to almost three times of the undisturbed soil and seven times of the remoulded soil. Therefore, reconstitution of soil using cement is found as effective method for improvement of compression  behaviour. This study also has established graphical interrelations between the compression index, swelling index and the cement content which can be used in the study of Kalomato.

scholarly journals Novel rapid measurement system of undisturbed soils water characteristics curve utilizing the continuous pressurization method

2019 ◽  
Vol 92 ◽  
pp. 07008 ◽  
Author(s):  
Adel Alowaisy ◽  
Noriyuki Yasufuku ◽  
Ryohei Ishikura ◽  
Masanori Hatakeyama ◽  
Shuu Kyono
Keyword(s):  
Soil Water ◽  
Unsaturated Soils ◽  
Natural Soil ◽  
Undisturbed Soil ◽  
Water Characteristics ◽  
Undisturbed Samples ◽  
In Situ Conditions ◽  
Undisturbed Soils ◽  
Short Time

Through this paper, a sampling methodology and a novel full automatic system adopting the continuous pressurization method which is capable of determining the Soil Water Characteristics Curve (SWCC) for both remoulded and undisturbed samples in a very short time were developed. The proposed system was validated by comparing the SWCCs of standard testing soils obtained using the developed system to the SWCCs obtained using a conventional method. Remoulded and undisturbed natural soil samples were tested, where the degree of disturbance influence on the obtained SWCC was discussed. In addition, the undisturbed samples containing moulds material influence on the obtained SWCC was investigated. It was found that remoulded samples do not properly represent the in-situ conditions with significant error that should be carefully considered when conducting analysis and proposing countermeasures against unsaturated soils related Geo-disasters. In addition, the material which the containing mould is made from has minor influence on the obtained SWCC which can be neglected. Finally, it can be concluded that the developed undisturbed soil water characteristics curve obtaining system is direct, rapid, reliable and simple. In addition, the proposed undisturbed sampling and testing methodology can be used to accurately evaluate the spatial variations of the SWCC regardless the heterogeneity of the soil profile.

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