Applied Mechanics and Materials Vols. 253-255

Abstract: The natural restoration capability of vegetation along the expressway is of vital importance for the slope revegetation and maintenance. The Margalef 's richness indexes (DMA), Shannon-Wiener's diversity index (Hp), Pielou's evenness (Jsw), Simpson Index (C), Importance Value Index (IVtr), Vegetation coverage and soil seed bank were used to assess the vegetation restoration capability of the expressway 25, Lu-Su section in China. Seventy-four quadrats ranged from 1 m X 1 m to 20 m X 20 m were studied and the analytical results indicated that Digitaria sanguinalis, Setariaviridis and Gramineae are the dominant species in the expressway slopes. Texture is the most important factor influencing the α diversity and vegetation coverage. Cinnamon soil is more suitable for the restoration compared with slopes the other kind of texture. The land use type and alien species invasion along the expressway are also vital important for the natural restoration. The soil seed bank in filling slope is more abundant than that of excavation slope. The natural restoration of vegetation along the expressway varies according to the site types and land use and most of the slopes have strong recovery ability.

Abstract: In this work we consider the problem of determining a set of optimal tolls on the arcs of a multicommodity transportation network. The problem is formulated as a bilevel mathematical program where the upper level consists in a government agency that regulate the traffic of the dangerous materials by imposing tolls on arcs of the network trying to minimize the risk for the population in the case when an accident occurs to the carriers, while the lower level is represented by a group of carriers traveling on shortest paths with respect to a generalized travel cost. So, the problem can be seen in a simplistic form as find the equilibrium between tolls that minimize the population exposure to the risk and tolls that are convenient for the shippers. The paper applies a path based algorithm to solve a bi-level multi-commodity optimal toll setting ‘hazmat’ problem. The algorithm consists in find upper bounds for the tolls considering the total cost and the risk associated to a particular path. We made several experiments and the results are shown in this work.

Abstract: The removal efficiencies of pollutants in the electrokinetic remediation with a new PRB (Permeable Reactive Barrier) method was studied for the remediation of groundwater contaminated by Pb in this paper. The experimental results showed that the pH value has varied obviously because of the oxidation and reduction near the electrodes, i.e. the pH value near the anode changed from 6.5 to 5.9 but near the cathode it varied from 6.4 to 8.9 in the experiment process, which indicated that the condition of acidity, alkalinity and other environment factors in groundwater had varied clearly during the electrokinetic remediation process. And the removal efficiency of Pb was respectively 57.84% near the anode and 92.60% near the cathode, and the removal efficiency of COD was respectively 40.28% near the anode and 90.40% near the cathode at the end of experiment when the experimental voltage gradient was 0.35V/cm, which made known that this new enhanced electrokinetic remediation of groundwater was more effective method than that of ordinary PRB technology in groundwater.

Abstract: Room-and-pillar mining method plays a dominant role in gypsum mines, which owns a low resource recovery ratio and has left many gobs leading a series of safety production problems to mining enterprises. To get an utmost resource recovery and avoid gob collapse, a secondary utilization scheme has been made by feasibility analysis and theoretical calculation. In this scheme, theoretical calculation about the occurrence conditions of mining damage has been done, and the deep research direction of the mining damage mechanism in gob-effect gypsum mines has been pointed out. This research and its train of thought could provide the gob-effect gypsum mines with reference that would increase ore recovery ratio and prevent mining damage.

Abstract: The natural and electrokinetic enhanced migration method was studied by the experiments in groundwater contaminated by heavy metal Pb in this work. The experimental results showed that the variation rule of Pb reflected that its migration was weak and the removal efficiency was only 9.30% near the anode in the natural seepage condition, but under the enhanced migration and remediation function, the pollutants could be enriched and removed faster, thus the removal efficiency of Pb was 46.72% near the anode at the end of experiment when the experimental voltage gradient was 0.28V/cm, which made known that this electrokinetic enhanced migration of Pb in contaminated groundwater was more effective method than that of natural seepage migration and enhanced the removal of contaminant in aquifer.

Abstract: In order to achieve urban and regional sustainable development, many strategic environmental assessment (SEA) practices for urban or regional comprehensive plans were conducted in China. An urban or regional comprehensive plan plays an important role in the planning system of China. Through three case studies, the paper examines how the SEAs incorporate environmental considerations into the urban or regional comprehensive plans in practice, and discusses the experiences and shortcomings. The findings show that support from government agencies, timely interaction with planners, participation of multi-stakeholders, linkage mechanism between SEA and project EIA, and improvement of environmental governance capacity can favor the integration of environment into the comprehensive plans. And more effort should be made to strengthen the general public participation and institutional analysis in the SEA practice in China.

Abstract: Based on the AVC theory, the highway landscape AVC evaluate frame on crossing Wetland has been found. On this foundation, we have established highway landscape Indicator set with crossing the Wetland .According to the evaluate Indicator set union concrete example on AHP which establishes carries on the fuzzy comprehensive judgment. Thereby the evaluate Indicator and the evaluate method have been proved having preferably practicability.

Abstract: River sand was used for filling embankment in highway for saving land resources and protecting farmland. In order to explore vibrating compaction characteristics of river sand, the effect of vibrating frequency, vibrating time, and moisture content on the indexes of dry density and modulus were investigated using orthogonal test design. The results indicate that the dry density values increase with the increase of three factors (vibrating frequency, vibrating time, and moisture content), while the modulus values increase with the increase of frequency and vibrating time, but decrease first then increase with the increase of moisture content. Vibrating frequency has a significant effect on dry density, but both vibrating time and moisture content have no significant effect, while three factors all have no significant effect on modulus.

Abstract: In order to achieve the goal of low-carbon development of the Beijing transportation, the changing trend of the transportation energy consumption and carbon emission is analyzed based on the inertia development of the present situation or under different macroscopic regulations so as to provide theoretical reference for transportation department to formulate development strategies effectively. According to the characteristics of the Beijing urban transportation system, first a energy consumption and carbon emission calculation model for urban road traffic and urban rail transit was established separately. Then the inertia-based prediction model of Beijing urban transportation energy consumption and carbon emission was established, by analyzing the development law of the related basic parameters using regression and other methods. According to the current policies, the development and prediction of part of the parameters were limited, and a scenario forecast model has been thus established (suitable up to 2020). Four types of scenario prediction examples under different policies were presented, and the contribution rate of each policy for carbon emission was analyzed.

Abstract: This essay discusses the effect of what the construction of the Metro Line Five of Guangzhou has to the development of existing central district and non-existed central district of Guangzhou City. Through the investigation and research into the quantity change of the public facilities around every exit of Metro Line Five within 500 meters, the essay analyses the planning guide effect of the construction of Metro Line Five to the land development and city construction of Guangzhou.