The effect of variable rock mass properties on pile-rock interaction poses a great challenge to the design of stabilizing piles and numerical analysis of pile-rock interaction. The paper presents a novel method to est...The effect of variable rock mass properties on pile-rock interaction poses a great challenge to the design of stabilizing piles and numerical analysis of pile-rock interaction. The paper presents a novel method to estimate the properties of weathered bedrock, which can be applied to routine design of landslide-stabilizing piles for collivial landslides. The Ercengyan landslide located in the Three Gorges Reservoir, China, is the area of interest for this study. A geological investigation and triaxial tests were conducted to estimate the basic parameters, including Geological Strength Index(GSI), uniaxial compressive strength σ_(ci) and Hoek-Brown constant m_i of intact bedrock in the study area. Hoek-Brown criterion was used to estimate mechanical properties of the weathered rock, including elastic modulus E_m, cohesion c, friction angle Φ, and normal ultimate lateral resistance p_(max). A parametric study was performed to evaluate the effect of parameterizations of GSI, σ_(ci) and m_i on the bedrock properties and p-y curves. The estimated rock mass properties were used with PLAXIS 2D software to simulate pile-rock interaction. Effect of GSI on stress at the pile-rock interface and in the rock, pile bending moment, pile shear force, and p-y curve were analysed.展开更多
As China vigorously promotes the development of new energy,photovoltaic power curtailment and wind power curtailment have been effectively resolved.At the same time,the yield from new energy power generation is becomi...As China vigorously promotes the development of new energy,photovoltaic power curtailment and wind power curtailment have been effectively resolved.At the same time,the yield from new energy power generation is becoming an important factor that affects the scale of investment in new energy.This paper focuses on the weather risks faced by wind power producers.By studying current research on weather index insurance in China and abroad,the functions and design methods for weather index insurance have been clarified.In addition,the feasibility of wind-power generation index insurance is discussed.The calculation methods for wind power generation index and the weather index insurance pricing methods for wind power enterprises are proposed.A weather index insurance model for wind power generation was established.The rationality and feasibility of the weather index insurance model proposed in this paper were verified using data from an existing power plant.The simulation results show that wind power enterprises can effectively avoid economic losses caused by weather risks through weather index insurance.展开更多
Climate change will lead to a variety of climate disasters, and climate disasters have a greater impact on China＇s food production. Weather index insurance is a new financial way to avoid risk of climate disasters ef...Climate change will lead to a variety of climate disasters, and climate disasters have a greater impact on China＇s food production. Weather index insurance is a new financial way to avoid risk of climate disasters effectively in China＇s food production. Firstly, the relationship between weather index insurance and food production in China was elaborated, and then the development status, advantages and disadvantages of weather index insurance in China at present were analyzed. Finally, some countermeasures against the problems of weather index insurance in China were put forward.展开更多
Young’s modulus(YM)of intact rock is an important parameter in the assessment of engineering behaviours of rock masses,and it cannot always be obtained in an economical and practical manner in laboratory experiments....Young’s modulus(YM)of intact rock is an important parameter in the assessment of engineering behaviours of rock masses,and it cannot always be obtained in an economical and practical manner in laboratory experiments.The main purpose of this study is to examine the capability of the minimax probability machine regression(MPMR),relevance vector machine(RVM),and generalised regression neural network(GRNN)models for the prediction of YM.The other aim is to determine the usefulness of a new index,the n-durability index(ndrb),which is based on porosity and the slake durability index.According to the regression analysis performed in this study,the n-durability index as an explanatory parameter performs better than the P-wave velocity(Vp),porosity,and slake durability index in the models,considering the results herein as well as the existing literature.According to regression error characteristic curves,Taylor diagrams,and performance indices,the best prediction model is MPMR,while the worst is the GRNN model.Although GRNN is the worst of the soft computing models,its performance is slightly better than that of the multiple linear regression(MLR)model.According to the results of the study,the MPMR and RVM models with ndrb and Vp are successful tools that can predict the YM of igneous rock materials to different degrees.展开更多
Based on the disaster reports,NCEP2.5X2.5 reanalysis data and radiosonde data of 11 national stations in Ulanqab region from June to August during 2012-2017,the weather situation classification and warning indicators ...Based on the disaster reports,NCEP2.5X2.5 reanalysis data and radiosonde data of 11 national stations in Ulanqab region from June to August during 2012-2017,the weather situation classification and warning indicators of thunderstorm and gale,hail and short-term heavy rainfall were studied.The results show that the cold vortex weather situation was easy to produce hail,and the falling area of severe convection could be found in the downstream of the cold vortex,the intersection area of jet stream at 200 and 500 hPa,and the wet area side of the 700 hPa main line.The cold trough type weather situation was easy to produce thunderstorm and gale,and the falling area of severe convection appeared on the right side of the upper jet stream axis,the left side of the lower jet stream axis,the wet side of the 700 hPa main line,and the east of the shear line at 700 hPa.The weather situation of the low trough and subtropical high type was dominated by short-term rainstorm,and the falling area of severe convection was on the right side of upper jet stream at 200 hPa,the left side of the low southeast jet stream,and the wet side of the 700 hPa main line.The warning index thresholds of the total index,the temperature change at 850-500 hPa with height,the height of 0 and-20℃layer,lifting condensation height,temperature dew point difference and mixing ratio were highly reliable.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 41002112)Key teaching construction projects of Wuhan Institution of Technology (J201403)+2 种基金the Chinese Postdoctoral Science Foundation (Grant No. 2017M621783, 2018T110527)the International Postdoctoral Exchange Fellowship Program by China Postdoctoral Council (Year 2017)the Startup Foundation for Introducing Talent of NUIST (Grant No. 2017r045)
文摘The effect of variable rock mass properties on pile-rock interaction poses a great challenge to the design of stabilizing piles and numerical analysis of pile-rock interaction. The paper presents a novel method to estimate the properties of weathered bedrock, which can be applied to routine design of landslide-stabilizing piles for collivial landslides. The Ercengyan landslide located in the Three Gorges Reservoir, China, is the area of interest for this study. A geological investigation and triaxial tests were conducted to estimate the basic parameters, including Geological Strength Index(GSI), uniaxial compressive strength σ_(ci) and Hoek-Brown constant m_i of intact bedrock in the study area. Hoek-Brown criterion was used to estimate mechanical properties of the weathered rock, including elastic modulus E_m, cohesion c, friction angle Φ, and normal ultimate lateral resistance p_(max). A parametric study was performed to evaluate the effect of parameterizations of GSI, σ_(ci) and m_i on the bedrock properties and p-y curves. The estimated rock mass properties were used with PLAXIS 2D software to simulate pile-rock interaction. Effect of GSI on stress at the pile-rock interface and in the rock, pile bending moment, pile shear force, and p-y curve were analysed.
基金supported by the State Grid Science and Technology Project (Research on Transnational Energy Interaction Simulation and Deduction Technologies of Global Energy Interconnection, JS71-17-004)
文摘As China vigorously promotes the development of new energy,photovoltaic power curtailment and wind power curtailment have been effectively resolved.At the same time,the yield from new energy power generation is becoming an important factor that affects the scale of investment in new energy.This paper focuses on the weather risks faced by wind power producers.By studying current research on weather index insurance in China and abroad,the functions and design methods for weather index insurance have been clarified.In addition,the feasibility of wind-power generation index insurance is discussed.The calculation methods for wind power generation index and the weather index insurance pricing methods for wind power enterprises are proposed.A weather index insurance model for wind power generation was established.The rationality and feasibility of the weather index insurance model proposed in this paper were verified using data from an existing power plant.The simulation results show that wind power enterprises can effectively avoid economic losses caused by weather risks through weather index insurance.
基金Supported by the Humanities and Social Sciences Key Program of Hubei Provincial Department of Education(15D024)Social Science Fund Program of Yangtze University(2014csy006)Open Fund General Program of Hubei Collaborative Innovation Center for Grain Industry(MS2015004)
文摘Climate change will lead to a variety of climate disasters, and climate disasters have a greater impact on China＇s food production. Weather index insurance is a new financial way to avoid risk of climate disasters effectively in China＇s food production. Firstly, the relationship between weather index insurance and food production in China was elaborated, and then the development status, advantages and disadvantages of weather index insurance in China at present were analyzed. Finally, some countermeasures against the problems of weather index insurance in China were put forward.
文摘Young’s modulus(YM)of intact rock is an important parameter in the assessment of engineering behaviours of rock masses,and it cannot always be obtained in an economical and practical manner in laboratory experiments.The main purpose of this study is to examine the capability of the minimax probability machine regression(MPMR),relevance vector machine(RVM),and generalised regression neural network(GRNN)models for the prediction of YM.The other aim is to determine the usefulness of a new index,the n-durability index(ndrb),which is based on porosity and the slake durability index.According to the regression analysis performed in this study,the n-durability index as an explanatory parameter performs better than the P-wave velocity(Vp),porosity,and slake durability index in the models,considering the results herein as well as the existing literature.According to regression error characteristic curves,Taylor diagrams,and performance indices,the best prediction model is MPMR,while the worst is the GRNN model.Although GRNN is the worst of the soft computing models,its performance is slightly better than that of the multiple linear regression(MLR)model.According to the results of the study,the MPMR and RVM models with ndrb and Vp are successful tools that can predict the YM of igneous rock materials to different degrees.
文摘Based on the disaster reports,NCEP2.5X2.5 reanalysis data and radiosonde data of 11 national stations in Ulanqab region from June to August during 2012-2017,the weather situation classification and warning indicators of thunderstorm and gale,hail and short-term heavy rainfall were studied.The results show that the cold vortex weather situation was easy to produce hail,and the falling area of severe convection could be found in the downstream of the cold vortex,the intersection area of jet stream at 200 and 500 hPa,and the wet area side of the 700 hPa main line.The cold trough type weather situation was easy to produce thunderstorm and gale,and the falling area of severe convection appeared on the right side of the upper jet stream axis,the left side of the lower jet stream axis,the wet side of the 700 hPa main line,and the east of the shear line at 700 hPa.The weather situation of the low trough and subtropical high type was dominated by short-term rainstorm,and the falling area of severe convection was on the right side of upper jet stream at 200 hPa,the left side of the low southeast jet stream,and the wet side of the 700 hPa main line.The warning index thresholds of the total index,the temperature change at 850-500 hPa with height,the height of 0 and-20℃layer,lifting condensation height,temperature dew point difference and mixing ratio were highly reliable.
