Lowland Technology International
The Lowland Technology International Journal presents activity and research developments in Geotechnical Engineering, Water Resources Engineering, Structural Engineering, Transportation Engineering, Urban Planning, Coastal Engineering, Disaster Prevention and Mitigation Engineering.
Articles
463 Documents
BEARING CAPACITY OF SPREAD FOUNDATIONS ON SAND OVERLYING CLAY
K. Yamamoto;
D. Kim
Lowland Technology International Vol 6 No 2, Dec (2004)
Publisher : International Association of Lowland Technology
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Second, the kinematic approach of limit analysis has been used to calculate the upper bound of the true ultimate bearing capacity. The kinematic solutions are upper bounds and their accuracy depends primarily on the nature of the assumed failure mechanism. This approach makes it convenient to create design charts, and it is possible to trace the influence of parameters. Third, the commercial finite element program ABAQUS was applied to obtain the ultimate bearing capacity based on the elasto-plastic theory. Although FE anlysis has still not gained wide acceptance in foundation practice, FE analysishas the great advantages in which the equations of equilibrium and compatibility are solved together, compared with limit analysis. Finally, results obtained from the kinematic approach and the program ABAQUS were compared with those from the existing limit ewuilibrium equations proposed by Yamaguchi, Meyerhof and Okamura et al. for confirming the validity of their application to practice.
ZONAL IMPACT ASSESSMENT BASED ON ZONAL COMMUNITY PREFERENCES: AN ALTERNATIVE OF LAND DEVELOPMENT CONTROL IN DEVELOPING COUNTRIES
K. Limapornwanitch;
K. Teknomo;
K. Hokao
Lowland Technology International Vol 6 No 2, Dec (2004)
Publisher : International Association of Lowland Technology
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Many planners have recently utilized the Development Impact Assessment framework focuses on the site specific level, and mostly concerns only limited types of development impacts. In fact, the city growths are the results of simultaneous developments and their adverse impacts are diverse, such as economic losses and environmental degradations. These become the limitations of impact assessment to manage the actual urbanizations. We have developed a framework of Zonal Impact Assessment (ZIA) to evercome those limitations. Our framework mainly evaluates the generated impacts in each zone rather than an isolated project. The ZIA can analyze the impacts of simultaneous developments in many zones, and many kinds of impacts can be considered. Furthermore, the survey results of public participation were included to identify the sensitive areas for development impact based on the preferences of zonal communities. The Bangkapi case study was elucidated to demontrate the ZIA application concerning traffic impacts of developments. The Impact distributions were evaluated and visualized for planning process. It wa found that ZIA is an alternative tool in balancing between infrastructure demands and urban developments to reach a sustainable community.
RESIDENTIAL LIFESTYLES AND ITS RELATIONSHIP WITH RESIDENTIAL ENVIRONEMNT EVALUATION: A CASE STUDY OF SAGA CITY, JAPAN
J. Ge;
K. Hokao
Lowland Technology International Vol 6 No 2, Dec (2004)
Publisher : International Association of Lowland Technology
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With the diversification of personal sense of values, as weel as the abundance of lifestyles, people's demands on residential environment are becoming more and more abundant. In this paper, by the case study of Saga City, the approaches to grasp the residential lifestyles are analyzed at first. Then, through each approach, the residential lifestyle patterns were classified, and the characteristics of each pattern were grasped. Furthermore, the relationship between residential lifestyle and residential environment evaluation are analyzed, and the suitable models for various styles were established. The results not only can be used as the rudimentary data for the improvement and development of residential environment, the mmethodology of considering residential lifestyle can also bring about a new and useful viewpoint for the further research of residential environment evaluation.
Evaluation of settlement behavior of the improved ground by using floating type columns during consolidation
Z. B. Jiang;
R. Ishikura;
N. Yasufuku
Lowland Technology International Vol 17 No 2, Sep (2015)
Publisher : International Association of Lowland Technology
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For soft soil engineering, in many cases, the foundation directly on natural ground cannot satisfy the requirement, such as embankment on deep soft clay layer. Consequently, a technology of combining the float-type cement-treated columns and surface stabilization is developed for reducing the settlement and the construction cost. In order to apply this technology for practice, it is important to predict the total settlement of the ground in relation to the important factors. In this paper, in order to evaluate the consolidation settlement behavior, a time-dependent skin friction model for the columnsoil interaction is developed to describe the nonlinear relationship between column shaft shear stresses and effective vertical pressure in the surrounding soft clay. The timedependent equivalent skin friction length which treating a part of floating type improved ground with a length of αH1 as an unimproved portion can be obtained based on a homogenization theoretical method. The compression settlement of this unimproved portion can be computed using the properties of soft clay alone. For verifying the effectiveness of this method, a set of laboratory model tests were performed. Furthermore, the settlement behavior and stress distribution characteristics were investigated by image analysis.
Effects of sugarcane bagasse ash (SCBA) on the strength and compressibility of cement stabilized peat
M. K. Abu Talib;
N. Yasufuku;
R. Ishikura
Lowland Technology International Vol 17 No 2, Sep (2015)
Publisher : International Association of Lowland Technology
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This research objective is to evaluate effectiveness of sugarcane bagasse ash (SCBA) inclusion in peat stabilization. To develop the optimal mix design, stabilized peat specimens were tested in unconfined compression. Energy Dispersive Xray (EDX) and Scanning Electron Microscope (SEM) apparatus was used to examine elemental composition and microstructure. Consolidation tests were carried out in a standard Oedometer apparatus on the obtained optimum peat-cement-bagasse (PCB) mixture. It was found that stabilized peat comprising 20% partial replacement of OPC with SCBA has the maximum UCS and discovered to be about 1.2 times greater than UCS of peatcement (PC) specimen. The UCS of optimum PCB mixture specimens increased with curing duration in water. Compared to untreated soil, SEM results for stabilized peat gave the significant pore improvement. EDX results prove that lower carbon (C) and higher calcium (Ca) fractions shows the better results of strength. There was a significant reduction of void ratio (e) for optimum PCB mixtures as compared to untreated peat. It was observed that preconsolidation pressure, σ’c were increase with curing period. Results finding shows that the stabilized peat Cα/Cc ratios were decline dramatically from untreated peat which is indicating the stabilized mixture can effectively reduce the secondary compression.
Performance of geosynthetic reinforcement on the ballasted railway track
L. S. Sowmiya;
J. T. Shahu;
K. K. Gupta
Lowland Technology International Vol 17 No 2, Sep (2015)
Publisher : International Association of Lowland Technology
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Geosynthetics provide an important option to improve track support stabilization and thereby reduce the track maintenance costs and operation costs due to train delays. In railroad construction, geosynthetics may be installed within or beneath the ballast or subballast layers. In this present study, model tests were performed on model tracks laid at 1:3 scale to the prototype with adequate thickness of subballast layer and placed on soft subgrade soils. Model tracks were adequately instrumented to record induced stresses and displacements in the track. Model tracks were reinforced with geogrid or geotextile or both at suitable interfaces. Track condition after a heavy rainfall was simulated. In this present study, three dimensional finite element analyses of geosynthetic reinforced railway track sections have been carried out using MIDAS/GTS 2013 and compared with unreinforced sections. The result shows that the reinforcement can be used to improve the performance of railway tracks on clayey subgrade.
Applying numerical method to understand the effect of climate change on the salinity intrusion in Ca River Basin, Vietnam
Q. T. Doan;
N. C. Don;
Y. C. Chen;
P. K. Mishra
Lowland Technology International Vol 17 No 2, Sep (2015)
Publisher : International Association of Lowland Technology
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Climate change and global warming are expected to have significant effects on water resources planning and management, especially in estuary areas. One-dimensional MIKE 11 model was established and applied to the Ca River Basin. The model was calibrated and validated with available hydrographical measured data in 1996, 1997, 1999 and 2000. The results of calibration and validation water level showed a high conformity about phase and water amplitude between calculated and observed data. The effect of global warming on salinity intrusion in estuarine areas was simulated in this study. The results of current state scenario (2010) and climate change scenario in 2020, 2050 and 2100 showed an overall effect of salinity intrusion process on precipitation and sea level rise. The distance of salinity intrusion in the river is increasing and this could be detrimental to the economic development, especially for the agriculture sector. The rise in sea level due to global warming will not significantly affect the situation of salinity intrusion for Ca River in 2020. However, comparing the results of scenario (2100) and the current state scenario (2010), the impact on salinity intrusion process in the Lam-Ca River system is found to be significant.
Identification of flood-prone areas by integrated remote sensing model
Mustaffa, A.A.;
A.W. Rasib;
M.I. Rosli;
M.A.M. Razi;
M.S. Adnan;
L.W. Tan
Lowland Technology International Vol 17 No 2, Sep (2015)
Publisher : International Association of Lowland Technology
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Flood is one of the main natural hazards that normally occurs every year in Malaysia. Flood causes inconveniences to human as well as life, property and financial losses. Floods cause a range of adverse impacts, including human injuries and fatalities, damages to crop, property, and public infrastructure. In this study, the identification of flood prone area has been done by integrated remote sensing images with the Soil Conservation System-Curve Number (SCS-CN). Johor Bahru city centre and Nusajaya of Iskandar Malaysia were selected as a study area since they are involved with the rapid development. A Landsat-5 image has been used in development of elevation model while the hydrological model was utilized to estimate the peak surface runoff. Based on the result, the flood prone areas for Skudai River and the Plentong River have been identified. The rapid changes in landuse has significantly has caused these area classified as high risk of flood areas. The development of this hazard map could be a used as a guideline in planning any development in this areas.
Strategies for energy efficiency renovation and evaluation system of existing residential building in hot summer and cold winter zone
M.Y. Lu;
J. Ge;
T.T. Shen;
X.Y. Luo
Lowland Technology International Vol 17 No 2, Sep (2015)
Publisher : International Association of Lowland Technology
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According to the climate characteristics in Hot Summer and Cold Winter (HSCW) zone, this study summarizes the special strategies for retrofitting the Existing Residential Buildings (ERB) in four aspects: envelop reformation, external environment improvement, energy saving behavior and renewable energy utilization. Then this study constructs the evaluation system frame of energy saving effect through 3 factors which are architecture design, construction and economic investment to comprehensively assess the practical effect of transforming. This research chooses a classical residential building in Huzhou as a case study and adopts the technologies to rebuild and uses the above evaluation system to figure out the most suitable reforming project. We hope our study about the reconstruction technologies and evaluation system can give some reference to renovation of existing residential buildings in other regions in China.
Spatial characteristics of Bantik ethnic community in Indonesia
P.P. Egam;
N. Mishima;
R. Goto;
Y. Taguchi
Lowland Technology International Vol 17 No 2, Sep (2015)
Publisher : International Association of Lowland Technology
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Settlement development of the Bantik community in Malalayang, Indonesia is related to the settlement position to the center of the city that affects the social interaction of the local society. This condition brings many changes especially to the traditional life and settlement of physical change. Characteristics of the settlement are physically hard to find even though the physical trail can be tracked because of the change of the settlement setting from rural society to urban society. Based on that consideration, this research is focused to the neighborhood characteristic through neighborhood activity analysis. The purpose of this research is to find the settlement characteristic through neighborhood activity. The first step is to analyze society’s social condition especially family composition. Next, to conduct an analysis of the house characteristic through terrace surrounding development linked with the outside activity. Based on this conducted analysis, the physical development occurs in the settlement. These developments affect the activities of neighbors in the settlement. Terrace and yard are the main space to form the communal activity with free movement without binding other spaces. On the contrary, the little shop has a connection with the yard and the street as related supports.