Natural fibers can be made into woven geotextile and combined with growing vegetation for slope protection. Thailand has highly abundant natural fibers and rural communities have been converting them into handicrafts. The water hyacinth yarns were fabricated to woven geotextile called limited life geotextiles (LLGs) to help stabilize the slope and improved the growth of vegetation for erosion control in geotechnical application. The study was aimed to assess the effectiveness of the LLGs new material for geotextile made from water hyacinth combined with Ruzi grass to control soil erosion in a representative slope. The erosion control test was performed by using the artificial rainfall. The flow rates of water runoff and amount of soil loss were investigated. Consequently, the limited life geotextiles made from water hyacinth LLGs combined with Ruzi grass can reduce the flow rate of runoff and amount of soil loss.
Nowadays, underground construction becomes popular as the demand for infrastructure in urban areas increases. To develop underground space in an urban area, it is important to investigate ground surface settlement and damage to existing neighbouring structures. Consequently, 3D finite element method (FEM) continuum models have been developed. This paper introduces a 3D FEM continuum model, which can consider, longitudinal joints, circumferential joints, and non-tension boundary between lining and ground, and examines the effect of boundary condition at the tunnel end and ground stiffness on the lining behavior (i.e., bending moment, axial force, normal effective earth pressure, and segment displacement) in the case of staggered building. As a result, it was found that the boundary condition at the tunnel end does not significantly affect the sectional force, except for the axial force in the case of soft soil; The two-ring model provides the safe side results from the viewpoint of segment design; and it can be adopted for segmental lining design and lining behavior simulation.
River basin management in Japan in the early modern period can be considered as providing a prototype of possible countermeasures for present-day flood exceeding the design level. The river basin management in the Saga region of Japan was established by Naritomi Hyogo in the early Edo era. This study evaluates characteristics of river basin management in Jobaru River Basin located in the eastern Saga Plain using numerical simulations and geotechnical surveys. A flood flow of Jobaru River was calculated using a 1-D flow numerical simulation. Overflow discharges from Nokoshi, open levee and no-levee intervals are estimated and these discharges are specified as boundary conditions for quasi 3-D inundation flow simulations. 2-D sediment transport by water flow is also simulated. A Geoslicer is used for field surveys that uncover clues of how the sediment has been deposited in the past. The ages of the sampled stratums was measured by using radiocarbon dating methods. The classified sediments columns and estimated ages of the stratum by the radiocarbon dating correspond to the simulated flood flow behavior in the retarding basin after overflow from the Nokoshi and open levee. Moreover, No.1 open levee reproduced by the geotechnical survey's result is used for the flow simulation successfully.
In the background of the bike-sharing program booming, this research carried an empirical investigation in Hangzhou, China to explore the usage pattern and attitude of different user groups. The actual benefits of this system were evaluated in the light of the expected utilities set up in the beginning and also data from other cities’ practices. By a methodological improvement on questionnaire sampling, it is found that besides the frequent user group, there are substantial amount of people who are occasional users or non-users. The latter two groups would be the target groups in the aim of enhancing the effectiveness of the system. By diagnosing the characteristics of the two target groups from the frequent user group in a statistic manner, the paper shed light on the efficient intervention arrangements what the governments should pay attention to. Also, by a comprehensive comparison of international cases, it is believed that although Hangzhou is already a leading city for bike-sharing program in China, there is substantial potential to improve it in terms of three indicators: average daily usage frequency, proportion of trips combined with public transportations, and proportion of trips converted from cars.
Landfill has been recognized as the cheapest and more acceptable form for the final disposal of municipal solid waste and as such has been the most used method in the world. Selection of appropriate landfill site is a complex task as the selection process involves many criteria. This paper presents the landfill site selection process of Savar Municipality. Initially, area required for future landfill site has been estimated considering without waste composting and with different percentages of composting. The estimation shows that, 4.09 to 9.96 acres of land will be required annually by 2025 for landfill. Then Multi Criteria Evaluation (MCE) approach has been used to identify suitable sites for landfill. After having set-up of selected criteria, scaling of criteria and weighting of criteria; suitability scores for eight landfill sites have been calculated. Two landfill sites have been chosen on the basis of their higher suitability score.
Ulaanbaatar city situates in Ulaanbaatar Folded System with presence of Mongolo-Baikal seismic zone. The presence of the Tuul River Valley dissected the basin with the formation of soft sediments transported by fluvial and Aeolian environments. The presence of scattered permafrost soil due to geo-climatic condition has led to freeze-thaw phenomena by physical weathering of the ground. This study reveals the influences of long-term tectonic and geo-climatic effects have brought up geotechnical problems in the area. Further it is advised that special attention need to be given in settlement of the area associated with mechanical disintegration of the ground, characterizing similar with lowlands along the valley bottom.
At this moment, India is among the countries of low level of urbanization. As a result, most urban settlements are characterized by shortfalls in stock housing and water supply, urban encroachments in fringe area, inadequate sewerage, traffic congestion, pollution, poverty and social unrest making urban governance a difficult task to maintain healthy urban environment. High rate of urban population growth is a cause of concern among India’s urban and town planners for efficient urban planning. Therefore, there is an urgent need to adopt modern technology of Remote Sensing and Geographic Information Systems to collect, to analyze, to model and to link the overall planning process to make planning process more effective and meaningful. Vijayawada is the second largest city in the state of Andhra Pradesh and in the close vicinity of newly constructing Capital, Amaravati of the newly formed state, located on banks of river Krishna is taken as a case study for observation of sprawl using a change detection method. It is found that Shannon’s entropy analysis method effective qualitative measure to identify the sprawl of Vijayawada city.