Application of Jute Fiber for the Improvement of Subgrade Characteristics
Md. Akhtar Hossain,
Md. Shakhawat Hossain,
Md. Kamrul Hasan
Issue:
Volume 3, Issue 2, March 2015
Pages:
26-30
Received:
23 January 2015
Accepted:
9 February 2015
Published:
2 March 2015
Abstract: Improvement in subgrade has always been an area of concern to highway and geotechnical engineers. In case of a highway, a weak subgrade results in greater thickness of pavement layer which increases the cost of pavement construction. To strengthen the subgrade soil, the use of jute fiber is advantageous because they are cheap, locally available, biodegradable, and eco-friendly. Jute fiber mixed randomly with subgrade soil has significant impact on the improvement of subgrade characteristics over the last decade. Keeping this in view an experimental study was conducted on locally available soil reinforced with jute fiber. In this study the soil samples were prepared at its maximum dry density corresponding to optimum moisture content in the CBR mold with and without reinforcement. The percentage of jute fiber by dry weight of soil was taken as 0.3%, 0.6%, 0.9%, and 1.2%. In the present investigation the length of fiber was taken as 15 mm and 30 mm, and two different diameters (4 mm and 8 mm) were considered for each fiber length. From the laboratory tests the effect of jute fiber content on density of soil (optimum moisture content and maximum dry density) was observed for each length and diameter of jute fiber. It was observed that the optimum moisture content increases and the maximum dry density decreases with the increase in jute fiber content for each length and diameter of jute fiber. The laboratory CBR values of soil and soil reinforced with fiber were determined. The effects of aspect ratio (length/diameter ratio) of jute fiber on CBR value of soil were also investigated. Test results indicate that CBR value of soil increases with the increase in length of jute fiber. It was also observed that increasing the diameter of jute fiber further increases the CBR value of reinforced soil, and this increase is substantial at fiber content of 1.2% for aspect ratio of 3.75 (length = 30 mm, diameter = 8 mm).
Abstract: Improvement in subgrade has always been an area of concern to highway and geotechnical engineers. In case of a highway, a weak subgrade results in greater thickness of pavement layer which increases the cost of pavement construction. To strengthen the subgrade soil, the use of jute fiber is advantageous because they are cheap, locally available, bi...
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Experimental and Numerical Approaches to Overtopping Levee Breach Effects in a River and Floodplain
Md. Serazul Islam,
Tetsuro Tsujimoto
Issue:
Volume 3, Issue 2, March 2015
Pages:
31-42
Received:
9 February 2015
Accepted:
26 February 2015
Published:
3 March 2015
Abstract: This paper described the results to identify, characterize, and simulate the levee breach effects in a river and floodplain by overtopping. One-side levee model is built in a laboratory experimental flume as well as numerical simulation using sand with proper compaction. An initial condition provided for the overflow breach is considered with partial crest opening. Small-scale laboratory experiments were performed to evaluate the effects of overtopping levee breaching and investigated simultaneous phenomena appears in a river, levee and floodplain, and validated the results with same scale numerical simulations; and the results of both approaches were in conformity. The failure behavior of an earthen levee focuses on the effects of material sizes, river bed slopes and bed variations relative to floodplain. According to the results, the higher bed level brings more rapid propagation of the levee breach and widening with more sediment deposition in the floodplain area as well as river bed degradation in the upstream of the levee breach point may cause further risk of the levee breach during the next flood. Using finer bed materials, river bed deformation and sediment deposition in the floodplain are clearly make differences with coarser materials, also it create the normal flow problem through the river in future.
Abstract: This paper described the results to identify, characterize, and simulate the levee breach effects in a river and floodplain by overtopping. One-side levee model is built in a laboratory experimental flume as well as numerical simulation using sand with proper compaction. An initial condition provided for the overflow breach is considered with parti...
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Dynamic Analysis of High Rise Seismically Isolated Buildings
Mohammed Naguib,
Fikry A. Salem,
Khloud El-Bayoumi
Issue:
Volume 3, Issue 2, March 2015
Pages:
43-50
Received:
23 February 2015
Accepted:
3 March 2015
Published:
13 March 2015
Abstract: The purpose of this paper is to offer a relative understanding of the seismic performance enhancements that a typical 40-story steel office building can achieve through the implementation of base isolation technology. To reach this understanding, the structures of a fixed-base office building and a base-isolated office building of similar size and layout were designed; their seismic performance was compared in both response spectrum analysis and time history analysis. As a result of this paper, building owners and construction industry professionals can recognize the benefits of implementing base isolation on a wider range of projects, thereby creating the potential for a significant increase in the technology’s use.
Abstract: The purpose of this paper is to offer a relative understanding of the seismic performance enhancements that a typical 40-story steel office building can achieve through the implementation of base isolation technology. To reach this understanding, the structures of a fixed-base office building and a base-isolated office building of similar size and ...
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