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Zheng J.,Zhejiang University | Zhao Y.,Zhejiang University | Lu Q.,Zhejiang University | Deng J.,University of Sichuan | And 2 more authors.
Engineering Geology | Year: 2016

Rock mass classification systems are common tools used in the design and construction of rock engineering. Numerous classification systems have been developed for rock slopes, of which the Slope Mass Rating (SMR) system is the most popular. Consequently, many rock slope classification systems have been derived from the SMR system. However, these systems are not good at determining the values of the two adjustment parameters F1 and F3, implying that the original SMR system may contain theory defects. In this paper, we propose some corrected methods for determining F1 and F3 and perform a series of analyses considering the three failure modes of rock slopes: plane, wedge, and toppling failures. The results of the discrepancy analysis from F1 illustrate that, with respect to each of the aforementioned three failure modes the calculated original SMR index is larger than, or equal to, the real value, and the designed slope is possibly in danger. The results of the discrepancy caused by the F3 illustrate that for each of the aforementioned three failure modes, the calculated original SMR index is smaller than, or equal to, the real value, and the designed slope might be conservative and not economical. © 2016 Elsevier B.V. Source

Qiu Z.-P.,Southwest Jiaotong University | Jiang H.-T.,Southwest Jiaotong University | Wang Q.,Southwest Jiaotong University | Liu Y.-Y.,Sichuan Academy of Environmental Science | And 2 more authors.
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2012

Based on the study of different effects of function-specialized microbes on the degradation of leachate and stabilization of landfill, a group of complex functional microbes were constructed to accelerate the stabilization of landfill. The complex flora had the greatest influences on the indices of leachate than other combined ones. The three indices including leachate volume, COD and concentration of ammonia nitrogen firstly reached the peak values at the initial stage of landfill then dropped apparently, and the values of three indices kept lower than those of other groups after 49d, 30d and 44d respectively. Moreover, the concentration of ammonia nitrogen reduced to less than 10 mg/L after 130d, which meet the requirements of ammonia nitrogen discharge of leachate according to GB16889-2008. In the whole period of landfill, cumulative volume of leachate, the total mass of COD and ammonia nitrogen were 26.66%, 26.59% and 25.40% lower than those of control groups respectively. This indicated that the pollution load of landfill was declined. Moreover, this complex flora also affected the indices of refuse stabilization most greatly. In contrast to the control groups, the concentrations of TOC, TN and C/N of refuse landfill decreased by 39.6%, 18.9% and 25.4% respectively at the end of landfill, while the settlement rate of waste and the biodegradation rate of organics increased by 9.99% and 26.23% respectively. Source

Li S.,University of Sichuan | Li S.,Sichuan Academy of Environmental Science | Hu X.,University of Sichuan | Tang Y.,University of Sichuan | Huang C.,University of Sichuan
Quaternary International | Year: 2014

Jiuzhaigou National Nature Reserve in southwest China is listed as a World Natural Heritage Site and has numerous alpine and subalpine travertine lakes. Over the past 240 years, agricultural expansion, tourism enhancement and other human activities have resulted in land use and land cover change. In this study, sediment cores from three lakes in Jiuzhaigou were collected to track the nature and intensity of these human activities in Jiuzhaigou as well as determine the influences of human activities on the lacustrine environment. Total organic carbon (TOC), total phosphorus (TP), total nitrogen (TN), carbon to nitrogen ratio (C/N), biogenic silica (BSi), heavy metal elements and other indicators were used to trace the evolution of the lacustrine sedimentary environment in Jiuzhaigou. The increased intensity in agricultural activities, large-scale deforestation, unsustainable tourism and other activities was clearly identified in the lake sediment records. Ecological restoration and decreased travel disturbance would reduce the levels of the various eutrophic substances and heavy metal elements in the lacustrine environment. Studying and understanding the response of lacustrine environment to human activities is of great significance for the protection and sustainable use of water and landscapes in the mountain lakes of Jiuzhaigou. © 2014 Elsevier Ltd and INQUA. Source

Duan X.,Chinese Research Academy of Environmental Sciences | Jiang Y.,National Center for Chronic and Noncommunicable Disease Control and Prevention | Wang B.,Chinese Research Academy of Environmental Sciences | Zhao X.,Chinese Research Academy of Environmental Sciences | And 6 more authors.
Applied Energy | Year: 2014

Household fuel-use (HFU) patterns are strongly associated with multiple effects, including air quality, human health, and regional climate change. This paper presents the results from the first Chinese Environmental Exposure-Related Human Activity Patterns Survey (CEERHAPS), carried out among 91,121 households located in 9108 villages, 636 towns, and 159 counties in 31 provinces. Face-to-face interviews were conducted with each participant to obtain information about the type of fuels used for cooking and heating. The main objectives of this paper were to investigate HFU for cooking and heating in China, to validate the World Health Organization (WHO) model, and to help inform local evaluation models. In China, gas and biomass fuels, the dominant energy fuels for cooking, are used by 44.8% and 32.1% of households, respectively. Approximately 34.1% of families have no household heating during the cold season, and 16.7%, 15.6% and 12.8% of households rely on coal, electricity, and biomass, respectively, for household heating when no central heating was available. The proportion of households using solid fuels has generally decreased during the last two decades. Considerable spatial variation was evident in the HFU patterns for both cooking and heating. The data revealed that the predominant fuel for cooking was biomass (47.6%) in rural populations, whereas urban households were more likely to cook with gas (65.8%). In terms of heating, coal (21.4%) and biomass (19.0%) were the main fuels used in rural households, while electricity (23.6%) and coal (10.5%) were more commonly used in urban areas. The overall HFU results for cooking from this study were comparable to those predicted using the WHO model. We also developed models at the provincial level to estimate HFU for cooking and heating in China; it is expected that the model, if confirmed by future studies, could be used for future research on household air pollution, domestic human exposure and burden of disease. © 2014 Elsevier Ltd. Source

Deng T.,Tianjin University of Science and Technology | Wu Y.,Sichuan Academy of Environmental Science | Yu X.,Tianjin University of Science and Technology | Guo Y.,Tianjin University of Science and Technology | And 2 more authors.
Applied Geochemistry | Year: 2014

Arsenic species including arsenite, arsenate, and organic arsenic were measured in the porewaters collected from Poyang Lake, the largest freshwater lake of China. The vertical distributions of dissolved arsenic species and some diagenetic constituents [Fe(II), Mn(II), S(-II)] were also obtained in the same porewater samples in summer and winter. In sediments the concentration profiles of total As and As species bound to Fe-Mn oxyhydroxides and to organic matter were also determined along with the concentrations of Fe, Mn and S in different extractable fractions. Results indicate that, in the summer season, the concentrations of total dissolved As varying from 3.9 to 55.8μg/L in sediments were higher than those (5.3-15.7μg/L) measured in the winter season, while the concentrations of total As species in the solid phase varied between 10.97 and 25.32mg/kg and between 7.84 and 30.52mg/kg on a dry weight basis in summer and winter, respectively. Seasonal profiles of dissolved As suggest downward and upward diffusion, and the flux of dissolved As across the sediment-water interface (SWI) in summer and winter were estimated at 3.88mg/m2a and 0.79mg/m2a, respectively. Based on porewater profiles and sediment phase data, the main geochemical behavior of As was controlled by adsorption/desorption, precipitation and molecular diffusion. The solubility and migration of inorganic As are controlled by Fe-Mn oxyhydroxides in summer whereas they appear to be more likely controlled by both amorphous Fe-Mn oxyhydroxides and sulfides in winter. A better knowledge of the cycle of As in Poyang Lake is essential to a better management of its hydrology and for the environmental protection of biota in the lake. © 2014 Elsevier Ltd. Source

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