Lowland Technology International
Online ISSN : 2187-8870
Print ISSN : 1344-9656
ISSN-L : 1344-9656
Volume 17 , Issue 2
Showing 1-8 articles out of 8 articles from the selected issue
Research Papers
  • Z.B. Jiang, R. Ishikura, N. Yasufuku
    2015 Volume 17 Issue 2 Pages 59-72
    Published: September 10, 2015
    Released: July 09, 2016
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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 column-soil interaction is developed to describe the nonlinear relationship between column shaft shear stresses and effective vertical pressure in the surrounding soft clay. The time-dependent 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.
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  • M.K. Abu Talib, N. Yasufuku, R. Ishikura
    2015 Volume 17 Issue 2 Pages 73-82
    Published: September 10, 2015
    Released: July 09, 2016
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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 X-ray (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 peat-cement (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.
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  • L.S. Sowmiya, J.T. Shahu, K.K. Gupta
    2015 Volume 17 Issue 2 Pages 83-92
    Published: September 10, 2015
    Released: July 09, 2016
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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.
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  • Q.T. Doan, N. C. Don, Y.C. Chen, P.K. Mishra
    2015 Volume 17 Issue 2 Pages 93-104
    Published: September 10, 2015
    Released: July 09, 2016
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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.
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  • Mustaffa A.A., A.W. Rasib, M.I. Rosli, M.A.M. Razi, M.S. Adnan, L. ...
    2015 Volume 17 Issue 2 Pages 105-110
    Published: September 10, 2015
    Released: July 09, 2016
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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.
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  • M.Y. Lu, J. Ge, T.T. Shen, X.Y. Luo
    2015 Volume 17 Issue 2 Pages 111-120
    Published: September 10, 2015
    Released: July 09, 2016
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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.
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  • P.P. Egam, N. Mishima, R. Goto, Y. Taguchi
    2015 Volume 17 Issue 2 Pages 121-128
    Published: September 10, 2015
    Released: July 09, 2016
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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.
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  • M. Kinashi, Y. X. Tan, T. Tribe
    2015 Volume 17 Issue 2 Pages 129-138
    Published: September 10, 2015
    Released: July 09, 2016
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    Nursery schools' needs are becoming more complex and diverse. Although a comprehensive policy that covers the guardians' requirements is therefore necessary, it is difficult to provide the wide variety of services required to adequately meet the needs of all the families who use nursery schools. This study aimed to identify priority matters for improvement of nursery school as part of the future improvement policy on the basis of the hypothesis that an improvement of issues that strongly influence evaluation of other issues would push up comprehensive evaluation of nursery school. The study objectives were authorized nursery schools located in Saga City in Japan, and a questionnaire survey evaluating the nursery schools was carried out. First, relationships among evaluation items were made clear through calculations of multiple correlation coefficient value by use of the questionnaire data. Second, the near future's important improvement matters for nursery schools were clarified by the construction of "evaluation structure model" through the Interpretive Structural Modeling (ISM) using these relationships. Through the analysis, the following matters of priority were identified: enhancement of educational services; appropriate placement of nursery school according to the relation to workplace location; and provision of a venue in the nursery schools that give guardians an opportunity to socialize with each other. Moreover, the study showed that these measures would improve the general value of nursery school.
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