LABORATORY FOOTING TEST ON PARTIALLY SATURATED SANDY SOIL

2016 ◽  
Vol 78 (5-5) ◽  
Author(s):  
J. D. Nyuin ◽  
M. J. Md Noor ◽  
Y. Ashaari ◽  
C. Petrus ◽  
A. Albar
Keyword(s):  
Sandy Soil ◽  
Ground Surface ◽  
Matric Suction ◽  
Shallow Foundation ◽  
Analysis And Design ◽  
Test Tank ◽  
Partially Saturated ◽  
Saturated Condition ◽  
Conventional Analysis ◽  
The Relationship

Conventional analysis and design of shallow foundation are based on the assumption that the soil is under fully saturated condition. However, shallow foundations are typically constructed near the ground surface where the soil is under partially saturated condition. Therefore, more research to investigate the behaviour of shallow foundation in unsaturated soil is very essential in order to aid engineers in making good analysis and design. This paper presents a series of laboratory footing tests conducted on unsaturated sandy soil. A specially designed test tank was fabricated for the test. Square footings of two different sizes (100 mm x 100 mm and 150 mm x150 mm) were used and loaded on Rawang sand which has residual suction value of 10 kPa. The measured values of matric suction of the soil in the test tank were in the range of 0 to 30 kPa. Based on the results, it was observed that bearing capacities of shallow foundation under fully saturated condition were the lowest compared to soil under unsaturated conditions. The highest values were measured at matric suction equals to residual suction (i.e 10 kPa). Furthermore, the relationship between the bearing capacities of shallow foundation with the matric suction was observed to be non-linear.    

scholarly journals CHARACTERISTICS OF UNDRAINED SHEAR BEHAVIOR OF SANDY SOIL UNDER PARTIALLY SATURATED CONDITION

2007 ◽  
Vol 63 (2) ◽  
pp. 334-343 ◽  
Author(s):  
Hiroshi NAKAZAWA ◽  
Kenji ISHIHARA ◽  
Yoshimichi TSUKAMOTO ◽  
Toshiyuki KAMATA
Keyword(s):  
Sandy Soil ◽  
Shear Behavior ◽  
Partially Saturated ◽  
Saturated Condition ◽  
Undrained Shear

scholarly journals Modeling the Temperature Field in the Ground with an Installed Slinky-Coil Heat Exchanger

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4010
Author(s):  
Monika Gwadera ◽  
Krzysztof Kupiec
Keyword(s):  
Temperature Field ◽  
Heat Exchanger ◽  
Surface Temperature ◽  
Ground Surface ◽  
Heat Sources ◽  
Ground Surface Temperature ◽  
Coil Heat Exchanger ◽  
The Relationship ◽  
Temperature Responses ◽  
Coil Heat

In order to find the temperature field in the ground with a heat exchanger, it is necessary to determine temperature responses of the ground caused by heat sources and the influence of the environment. To determine the latter, a new model of heat transfer in the ground under natural conditions was developed. The heat flux of the evaporation of moisture from the ground was described by the relationship taking into account the annual amount of rainfall. The analytical solution for the equations of this model is presented. Under the conditions for which the calculations were performed, the following data were obtained: the average ground surface temperature Tsm = 10.67 °C, the ground surface temperature amplitude As = 13.88 K, and the phase angle Ps = 0.202 rad. This method makes it possible to easily determine the undisturbed ground temperature at any depth and at any time. This solution was used to find the temperature field in the ground with an installed slinky-coil heat exchanger that consisted of 63 coils. The results of calculations according to the presented model were compared with the results of measurements from the literature. The 3D model for the ground with an installed heat exchanger enables the analysis of the influence of miscellaneous parameters of the process of extracting or supplying heat from/to the ground on its temperature field.

Object-oriented and conventional analysis and design methodologies

Computer ◽  
1992 ◽  
Vol 25 (10) ◽  
pp. 22-39 ◽  
Author(s):  
R.G. Fichman ◽  
C.F. Kemerer
Keyword(s):  
Object Oriented ◽  
Analysis And Design ◽  
Design Methodologies ◽  
Conventional Analysis

Experimental Research on the Relationship between Surface Polishing and Fracture Strength for Ground Ceramics

2013 ◽  
Vol 770 ◽  
pp. 433-436
Author(s):  
Xin Li Tian ◽  
Jian Quan Wang ◽  
Bao Guo Zhang ◽  
Peng Xiao Wang
Keyword(s):  
Residual Stress ◽  
Fracture Strength ◽  
Ground Surface ◽  
Residual Tensile Stress ◽  
Residual Stress Field ◽  
Polishing Process ◽  
Machined Surface ◽  
X Ray ◽  
Surface Polishing ◽  
The Relationship

Fracture strength is one of the key mechanics performances for engineering ceramics products, greatly influenced by the microscopic topography and residual stress field of ground surface. In this work, several testing equipments, such as the metallurgical microscope, surface profiler and X ray residual stress tester were introduced to investigate the relationships between microscopic topography, surface roughness, residual stress and fracture strength of ground ceramics, after the surface grinding and mechanical polishing. The experimental results show that a smoother machined surface with low roughness and residual stress is obtained through polishing with absolute alcohol for 20 minutes; the fracture strength of Si3N4SiC and Al2O3 are increased by 6.64%8.18% and 6.58% respectively, comparing to the ceramics without polishing; the surface stress concentration and residual tensile stress of polished ceramics are both reduced after an appropriate time of polishing process, which causes a certain improvement of ground fracture strength.

scholarly journals The Effects of Landscape Elements on the Breeding Sites of Bloodsucking Midge

2021 ◽  
Vol 13 (5) ◽  
pp. 2863
Author(s):  
Kaowen Grace Chang ◽  
Hungju Chien
Keyword(s):  
Ground Surface ◽  
Preventive Strategies ◽  
Careful Selection ◽  
Public Concern ◽  
Breeding Sites ◽  
Algae Growth ◽  
Potential Habitats ◽  
Landscape Factors ◽  
The Relationship ◽  
Selection Of

Forcipomyia taiwana, a bloodsucking midge that is one of the most irritating biting pests in Taiwan, has raised widespread public concern. However, we have little information about the extent to which landscape factors affect their potential habitats. As a result, landscape professionals do not have enough information to implement preventive strategies to control midges. The purpose of this study is to investigate the relationship between landscaping and algae growth for larval breeding sites of Forcipomyia taiwana. The intent is to determine the environmental strategies that make the planned landscape unsuitable for midges to breed. GIS based on data collected from 16 constructed landscape sites (317,187 m2 in total) was utilized to spatially examine the relationship between the occurrence of the algae for midge breeding sites and the ground surface types and planting characteristics in each landscape. The results revealed that the potential midge habitats can be controlled through careful selection of the ground surface, the improvement of the site drainage, and choosing plants with the appropriate characteristics. Apart from choosing the appropriate type of paving surface, the integrity of the paving installation and the coverage of the ecological surface also influence prevention efficacy.

Mechanically Aspirated Solar Radiation Shields: A CFD and Neural Network Design Analysis

2001 ◽  
Author(s):  
B. M. Fichera ◽  
R. L. Mahajan ◽  
T. W. Horst
Keyword(s):  
Neural Network ◽  
Solar Radiation ◽  
Temperature Sensor ◽  
Temperature Measurements ◽  
Analysis And Design ◽  
Computational Fluid Dynamics Analysis ◽  
Radiation Shields ◽  
Input Variables ◽  
The Relationship

Abstract Accurate air temperature measurements made by surface meteorological stations are demanded by climate research programs for various uses. Heating of the temperature sensor due to inadequate coupling with the environment can lead to significant errors. Therefore, accurate in-situ temperature measurements require shielding the sensor from exposure to direct and reflected solar radiation, while also allowing the sensor to be brought into contact with atmospheric air at the ambient temperature. The difficulty in designing a radiation shield for such a temperature sensor lies in satisfying these two conditions simultaneously. In this paper, we perform a computational fluid dynamics analysis of mechanically aspirated radiation shields (MARS) to study the effect of geometry, wind speed, and interplay of multiple heat transfer processes. Finally, an artificial neural network model is developed to learn the relationship between the temperature error and specified input variables. The model is then used to perform a sensitivity analysis and design optimization.

scholarly journals Adopting Numerical Models for Prediction of Ground Movements Induced by Deep Excavation

2020 ◽  
Vol 8 (6) ◽  
pp. 976-989
Keyword(s):  
Numerical Models ◽  
Ground Surface ◽  
Sensitivity Study ◽  
Design Criterion ◽  
Deep Excavation ◽  
Soil Behavior ◽  
Analysis And Design ◽  
Ground Movements ◽  
Codes Of Practice ◽  
Adjacent Structures

Control of ground surface settlement induced by deep excavation is of major concern in order to attain safety of adjacent structures and utilities against excessive or differential settlements. Accurate prediction of ground surface movements is an important design criterion in the analysis and design of excavation supporting systems. Many codes of practice are based on a design criterion that satisfies a factor of safety preventing collapse of the system and its surrounding soil. In this research, finite element modeling is adopted to numerically simulate the performance of deep excavation systems and the associated ground movements. The soil behavior was simulated using two types of models; the Mohr-Coulomb model (MC) and the Hardening Soil Model (HS). Field data from monitoring a real deep excavation case history of a retaining system was considered to check the validity of the proposed numerical modeling. A simpler equivalent section replacing the multi-layered soil profile was verified. Then, a sensitivity study has been conducted to study the influence of major parameters that affect ground movements induced by deep excavation. The results of the parametric study were accomplished to construct design charts and drive empirical equations by implementing a design parameter, called the "Stiffness Ratio (R)”, that represents the supporting system stiffness. From these suggested charts and equations, the percentage of maximum vertical ground movements to wall height can be estimated.

scholarly journals Interval Observer Design for Metzlerian Takagi-Sugeno Systems

2020 ◽  
Author(s):  
Dušan Krokavec ◽  
Anna Filasová
Keyword(s):  
Continuous Time ◽  
Observer Design ◽  
Asymptotic Convergence ◽  
Observer Error ◽  
Analysis And Design ◽  
Interval Observer ◽  
Takagi Sugeno ◽  
Positive Observer ◽  
The Relationship

The generalized interval observer design conditions for continuous-time Metzlerian Takagi-Sugeno systems are presented in the paper. Attention is focused on the analysis and design guaranteeing the asymptotic convergence of the interval observer error and positivity of interval observer state. The relationship between the nonnegativity of the observer gains and the corresponding positive observer state attractiveness is also shown. The method presented extends and generalizes the results that recently appeared in the literature.

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