This paper aims to study effect of roots of vegetation on the stability of soil along slopes and also soil erosion. The effects of root reinforcement depend on the morphological characteristics of the root system, the tensile strength of grass roots, and the spatial distribution of the roots in the soil. The experiments were carried out to evaluate the root tensile strength of two different grasses namely: Vetiver and Ruzi grasses, by conducting the laboratory tensile tests and field direct shear tests. For each type of grass, single root specimens were sampled and tested for their ultimate tensile strength and Young's modulus in the laboratory tests. The results of laboratory tests revealed the significant correlations between root diameter and tensile force or tensile strength and Young's modulus of Ruzi and Vetiver grasses. In addition, large scale field direct shear tests were carried out involving roots of Vetiver and Ruzi grasses to evaluate the contributions of their root systems to the soil shear strength. Vetiver roots contributed higher components of shear strength compared to Ruzi grass. However, it was found that the combination of Ruzi and Vetiver grass roots yielded much better effects than Vetiver grass alone. It can be concluded that the Vetiver grass roots help enhanced the shear strength for soil reinforcement while the short roots of Ruzi grass can help control surface soil erosion.

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Full scale field experimentations were incorporated along the downstream of the Chikugo River, Saga, Japan in order to observe the effect of wooden raft and pile foundation on the soft clay. In this study, the wooden raft and pile foundation was utilised for the marginal strip to understand the disposition of vertical settlements and lateral displacements of the ground. Cypress wood was taken into consideration in order for constructing raft and pile. Two different types of wooden raft and pile foundations with same dimensions were installed in the ground. The wooden raft installed with single-sided assemblages of wooden piles was configured as Case I. While, the same raft with both-sided assemblages of wooden piles was configured as Case II. A new embankment was constructed embedded with the existed ones on the river dike. The study was carried out for 136 days span of time from the beginning of the embankment construction. The results showed that both side assemblages of wooden piles were more effective to prevent the lateral displacement, reduce the vertical settlement and local deformation of the dike and the surrounding ground with compared to the single-sided installed piles of the similar foundation structure. The test results confirmed that the river dike supported by the wooden raft and pile foundation can be anticipated as more stable on sand layer of the soft ground within the depth of pile length.

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Lowlands are easily concentrated by effects of water and soil pollution. There is a demand for the development of technology that can both restore the ground environment and improve soft ground. The authors implemented testing used a rotary crushing and diffusive mixing (referred to hereafter as RCDM) method and an ion adsorption method (Nano-size inorganic Layered Double Hydroxide - NLDH - method) for the purpose of developing technology that can restore the ground environment and improve soft ground. These examples are believed to show the broad applicability of both methods.

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As residential energy consumption increases recently, there is greater focus of the energy conservation activities in residential sector. The combined cooling, heating and power (CHP) system, a well-known distributed energy system technology, has been paid more and more attention. In this paper, the performances of typical CHP systems are investigated for a cooperative housing block (CHB), a mixed residential development pattern recently popularized in Japan. Based on the building's energy consumption, CHP technologies have been assumed and assessed following two design and management modes, namely heat tracking mode and electricity tracking mode. In order to obtain a comprehensive understanding of the performance of the assumed CHP systems in CHB, the system is assessed under different area functional proportion (AFP) and area social age structure (ASAS, the proportion of housing styles for different age groups). It can be proved that the cooperative use of CHP system in CHB is better than individual use in the conventional housing development. In addition, the CHP system can perform better if the urban planner properly design the function formation and consider the lifestyle of residents in different ages.

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Building density in a master plan directly affects the outdoor physical environmental quality in residential area. Inappropriate design of a layout may cause impact on external comfort, such as lack of air movement. To tackle this problem, a dimensional variable, named as ventilation space was defined to feature the building density in a master plan. It consists of the gable space and fore-and-aft space. The Reynolds averaged equations and the renormalization group (RNG) κ-ε turbulence model was used to simulate the wind condition in some typical layouts under the weather condition in Hangzhou, China. The simulated wind conditions were assessed using the criteria, the wind speed ratio at some key locations on pedestrian level. The effects of the ventilation space on the air movement were discussed and an optimal space was derived for each of the modeled layouts. The set of results were expected to be used as a rule of thumb by architects and planners in master planning stage.

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The problem of continuous increasing of carbon dioxide emissions in line with higher energy demand in Thailand has been called for attention under global warming conditions. In order to tackle with this problem, transportation was found as a major sector in an escalation of energy consumption which is the cause of carbon emission. As a developing country, infrastructure development has always been focused on an increasing of supply side, while less promote on public transportation and almost ignore for nonmotorization. The purpose of this study is to propose the method for measuring factors associated with pattern of walking behavior in connecting to public transportation usage by selecting Bangkok Mass Transit System as a case study. The results demonstrated different dimension of built environment aspects influence on different level of pedestrians' satisfaction. Thus, transportation planners should consider different context of urban area as a key parameter to provide future metropolitan transportation while allocate appropriate strategy and management policy to create walkable urban place to shift in travel mode from vehicles to transit or active transportation.

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Waterlogged valley bottom soils of Tropical Savannah are areas where the richest traditional cropping systems are found, but they also face adverse physico-chemical conditions which can drastically drop rice yield. Subsurface drainage has been used for many areas to alleviate waterlogging. However, this drainage is dependent on clay distribution, type and location. The current paper analyses these factors for the case of Tiefora, a 16 ha valley bottom irrigated rice scheme in Burkina Faso. For this purpose, nine boreholes, with depths from 2 to 6 m, were realised. A total of 51 samples of soils were extracted at various depths, based on soil changes in texture and colour. These samples underwent grain-size-analysis. A comparative non-linear regression was performed on the clay distribution. Quadratic regression was the most appropriate. In addition, clay proportions were high - 20-30% in the 2 m topsoil - in the upstream and middle areas. A more important - 30-40% - peak was reached in the downstream area at 1 m, with a much smaller thickness (less than 50 cm) and higher permeability. These results suggest the application of mole drainage in the valley, except downstream where the classical Hooghoudt pipe subsurface drainage can be implemented.

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