Due to the size effects of rockfill materials, the settlement difference between numerical simulation and in situ monitoring of rockfill dams is a topic of general concern.The constitutive model parameters obtained fr...Due to the size effects of rockfill materials, the settlement difference between numerical simulation and in situ monitoring of rockfill dams is a topic of general concern.The constitutive model parameters obtained from laboratory triaxial tests often underestimate the deformation of high rockfill dams.Therefore, constitutive model parameters obtained by back analysis were used to calculate and predict the long-term deformation of rockfill dams.Instead of using artificial neural networks (ANNs), the response surface method (RSM) was employed to replace the finite element simulation used in the optimization iteration.Only 27 training samples were required for RSM, improving computational efficiency compared with ANN, which required 300 training samples.RSM can be used to describe the relationship between the constitutive model parameters and dam settlements.The inversion results of the Shuibuya concrete face rockfill dam (CFRD) show that the calculated settlements agree with the measured data, indicating the accuracy and efficiency of RSM.展开更多
To enhance the general knowledge of landslides in China, the DAAD （German Academic Exchange Service） is financing an investigative project. As part of this project, at the Qingjiang （清江） River, a 10 km^2 area do...To enhance the general knowledge of landslides in China, the DAAD （German Academic Exchange Service） is financing an investigative project. As part of this project, at the Qingjiang （清江） River, a 10 km^2 area downstream of the Shuibuya （水布垭） dam site was geologically and geotechnicaUy mapped to gather information concerning landslides and their correlation to lithology, slope angles and texture. The geological mapping contained the characterization of the lithological units. The characterization of the shape of landslides and the classification of rocks into units with similar geotechnical behavior is contained in the geotechnical map. Samples were taken and investigated using X-ray diffraction to identify the clay minerals and geotechnical tests to determine the effective shear angle and cohesion of rocks and soils. Geotechnical mapping showed a close connection between lithology, slope angle and texture concerning the occurrence of landslides. Most landslides occur on the northern bank of the Qingjiang River where the dip angle of the bedding is nearly parallel to the slope, resulting in potential and effective slide planes. On the southern bank only sporadic and small landslides occur because the bedding is antipodal to the slope angle. This pilot work is a base for further and more detailed investigations in this area.展开更多
The complicated rock structures and the stability of surrounding rocks of the underground powerhouse were the key rock mechanical problems in Shuibuya hydropower station.In order to overcome the related rock mechanica...The complicated rock structures and the stability of surrounding rocks of the underground powerhouse were the key rock mechanical problems in Shuibuya hydropower station.In order to overcome the related rock mechanical problems encountered during its construction,a comprehensive research was carried out for the underground powerhouse in Shuibuya hydropower station based on a detailed geological survey.It covers the investigations on the initial in-situ stress distribution features,rock mechanical properties,engineering rock mass classifications by different methods,numerical modeling for stability and support analysis,proper measures for rock excavation and support.The results show that the rock excavations of the underground powerhouse under the given geological conditions can be controlled effectively.Some measures,suggested by the designers,are proved to be rational and effective.These measures mainly consist of:(1) the soft rock replacements by concrete in local area below the crane beam,(2) the shotcrete and reinforcement by rock bolts and anchor cables in surrounding rocks,and (3) 2 m concrete placement on the rock bench between adjacent tailrace tubes.The engineering practice shows that the treated surrounding rocks have a good overall stability.The deformation behaviors observed by safety equipments are within the designing limits.The research conclusions on the related rock mechanical problems,prior to the underground powerhouse excavations,are reliable.展开更多
Scale effect is one of the important aspects in the macro mechanical parame- ters’ research of rock mass, from a new point of view, by means of lab and field rock me- chanics test, establishment of E^Vp relation, cla...Scale effect is one of the important aspects in the macro mechanical parame- ters’ research of rock mass, from a new point of view, by means of lab and field rock me- chanics test, establishment of E^Vp relation, classification of engineering rock mass, nu- merical simulation test and back analysis based on surrounding rock’s displacement monitoring results of Shuibuya Project’s underground power station, rock mass deforma- tion module’s size effect of surrounding rock of Shuibuya Project’s undegroud power sta- tion was studied. It’s shown that rock mass deformation module’s scale effect of sur- rounding rock of Shuibuya Project’s undeground power station is obvious, the rock mass deformation module to tranquilization is 20% of intact rock’s. Finally the relation between rock mass deformation modules and the scale of research was established.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51579193)the Science and Technology Planning Project of Guizhou Province(Grant No.[2016]1154)
文摘Due to the size effects of rockfill materials, the settlement difference between numerical simulation and in situ monitoring of rockfill dams is a topic of general concern.The constitutive model parameters obtained from laboratory triaxial tests often underestimate the deformation of high rockfill dams.Therefore, constitutive model parameters obtained by back analysis were used to calculate and predict the long-term deformation of rockfill dams.Instead of using artificial neural networks (ANNs), the response surface method (RSM) was employed to replace the finite element simulation used in the optimization iteration.Only 27 training samples were required for RSM, improving computational efficiency compared with ANN, which required 300 training samples.RSM can be used to describe the relationship between the constitutive model parameters and dam settlements.The inversion results of the Shuibuya concrete face rockfill dam (CFRD) show that the calculated settlements agree with the measured data, indicating the accuracy and efficiency of RSM.
基金This paper is supported by the DAAD ( German Academic ExchangeService) within the project"Landslides after Heavy Rainfallsin China".
文摘To enhance the general knowledge of landslides in China, the DAAD （German Academic Exchange Service） is financing an investigative project. As part of this project, at the Qingjiang （清江） River, a 10 km^2 area downstream of the Shuibuya （水布垭） dam site was geologically and geotechnicaUy mapped to gather information concerning landslides and their correlation to lithology, slope angles and texture. The geological mapping contained the characterization of the lithological units. The characterization of the shape of landslides and the classification of rocks into units with similar geotechnical behavior is contained in the geotechnical map. Samples were taken and investigated using X-ray diffraction to identify the clay minerals and geotechnical tests to determine the effective shear angle and cohesion of rocks and soils. Geotechnical mapping showed a close connection between lithology, slope angle and texture concerning the occurrence of landslides. Most landslides occur on the northern bank of the Qingjiang River where the dip angle of the bedding is nearly parallel to the slope, resulting in potential and effective slide planes. On the southern bank only sporadic and small landslides occur because the bedding is antipodal to the slope angle. This pilot work is a base for further and more detailed investigations in this area.
基金Supported by the National Key Technology R&D Program of China (2008BAB29B01)
文摘The complicated rock structures and the stability of surrounding rocks of the underground powerhouse were the key rock mechanical problems in Shuibuya hydropower station.In order to overcome the related rock mechanical problems encountered during its construction,a comprehensive research was carried out for the underground powerhouse in Shuibuya hydropower station based on a detailed geological survey.It covers the investigations on the initial in-situ stress distribution features,rock mechanical properties,engineering rock mass classifications by different methods,numerical modeling for stability and support analysis,proper measures for rock excavation and support.The results show that the rock excavations of the underground powerhouse under the given geological conditions can be controlled effectively.Some measures,suggested by the designers,are proved to be rational and effective.These measures mainly consist of:(1) the soft rock replacements by concrete in local area below the crane beam,(2) the shotcrete and reinforcement by rock bolts and anchor cables in surrounding rocks,and (3) 2 m concrete placement on the rock bench between adjacent tailrace tubes.The engineering practice shows that the treated surrounding rocks have a good overall stability.The deformation behaviors observed by safety equipments are within the designing limits.The research conclusions on the related rock mechanical problems,prior to the underground powerhouse excavations,are reliable.
文摘Scale effect is one of the important aspects in the macro mechanical parame- ters’ research of rock mass, from a new point of view, by means of lab and field rock me- chanics test, establishment of E^Vp relation, classification of engineering rock mass, nu- merical simulation test and back analysis based on surrounding rock’s displacement monitoring results of Shuibuya Project’s underground power station, rock mass deforma- tion module’s size effect of surrounding rock of Shuibuya Project’s undegroud power sta- tion was studied. It’s shown that rock mass deformation module’s scale effect of sur- rounding rock of Shuibuya Project’s undeground power station is obvious, the rock mass deformation module to tranquilization is 20% of intact rock’s. Finally the relation between rock mass deformation modules and the scale of research was established.
