The design protection of the base of the Bratsk HPP （Hydroelectric Power Station） dam from filtration coming from the water reservoir included the arrangement of several cement-grout curtains and the system of drain...The design protection of the base of the Bratsk HPP （Hydroelectric Power Station） dam from filtration coming from the water reservoir included the arrangement of several cement-grout curtains and the system of drainage holes in the 2nd and 4th columns. During operation, increased hydrostatic back pressure at the base of the dam was found, which indicated the low efficiency of the base design protection. To reduce back pressure B. E. Vedeneev Hydro Technic Institute proposed the device of “advanced” drainage holes from the cement-grout gallery near the upstream face. The implementation of the proposal in a number of sections of the dam has led to a decrease in back pressure, but affected filtration in the drainage system, increasing it significantly. The article examines filtration features of “advanced” drainage holes and their dependence on the severity of winters. The spread of the practice of “advanced” drainage in other sections of the dam requires caution and further investigations of the nature of filtration.展开更多
The Heber River Diversion Dam （Heber Dam） and 3.6 km penstock on Vancouver island, British Columbia, Canada was built in 1953 and by 2009, it had reached the end of its useful life due to the deteriorated wooden str...The Heber River Diversion Dam （Heber Dam） and 3.6 km penstock on Vancouver island, British Columbia, Canada was built in 1953 and by 2009, it had reached the end of its useful life due to the deteriorated wooden structures. A decision was taken to remove the dam, return the flows in the Heber River to pre-dam conditions and restore the footprint of the dam and penstock. Plans were developed for removal of the dam and contaminated materials including the creosote coated wooden penstock and other wooden structures associated with the dam and site restoration. Work on removal and restoration was undertaken over the summer and fall of 2012 and the spring of 2013. Restoration treatments were based on the use of natural processes as a model for recovery. The recovery of dam and penstock removal disturbances was initiated in the late summer and fall of 2012 with the fall dispersal of seeds from mature pioneering species that formed a significant part of the local undisturbed vegetation. This paper describes the treatments that were applied to enhance the natural recovery of the disturbed areas and the results of those treatments. The restoration treatments were designed to address the filters that were present in project areas. These were identified during an initial inspection in 2009 and were centred on compaction of substrates and a lack of micro-sites. In addition to the use of natural processes for the restoration of project disturbances, a local First Nations crew was hired to transplant sword ferns （Polystichum munitum （Kaulf.） C. Presl） from the adjacent forest areas onto project sites to provide a social benefit from the restoration work.展开更多
One of the possible negative environmental effects of hydropower stations is the supersaturation of total dissolved gas (TDG) downstream of high-dams,which can lead to gas bubble disease or even death of fish. By taki...One of the possible negative environmental effects of hydropower stations is the supersaturation of total dissolved gas (TDG) downstream of high-dams,which can lead to gas bubble disease or even death of fish. By taking the TDG as the main study object,the paper launched the TDG field observations on Zipingpu,Three Gorges,Ertan,Manwan,Dachaoshan,Gongzui and Ertan dams in China. The factors affecting TDG generation and dissipation were explored. Energy dissipation structures,spill rates and operation patterns were the main factors causing TDG supersaturation. TDG saturations are essentially the same in the hydro-electric tail water and in the upper reaches,so hydro-electric tail water can be less TDG supersaturated through mixing downstream. The main factors affecting the dissipation process of the supersaturated TDG were tributary convergence,water depth and turbulence. TDG supersaturation was unevenly distributed in both the vertical and transverse directions. This study is important because it adds to the accumulating experience of TDG field observations of dam projects in China,and because it objectively and impartially evaluates the impacts of supersaturated TDG. The study also provides field data and references for future studies of TDG supersaturation caused by high-dams.展开更多
文摘The design protection of the base of the Bratsk HPP （Hydroelectric Power Station） dam from filtration coming from the water reservoir included the arrangement of several cement-grout curtains and the system of drainage holes in the 2nd and 4th columns. During operation, increased hydrostatic back pressure at the base of the dam was found, which indicated the low efficiency of the base design protection. To reduce back pressure B. E. Vedeneev Hydro Technic Institute proposed the device of “advanced” drainage holes from the cement-grout gallery near the upstream face. The implementation of the proposal in a number of sections of the dam has led to a decrease in back pressure, but affected filtration in the drainage system, increasing it significantly. The article examines filtration features of “advanced” drainage holes and their dependence on the severity of winters. The spread of the practice of “advanced” drainage in other sections of the dam requires caution and further investigations of the nature of filtration.
文摘The Heber River Diversion Dam （Heber Dam） and 3.6 km penstock on Vancouver island, British Columbia, Canada was built in 1953 and by 2009, it had reached the end of its useful life due to the deteriorated wooden structures. A decision was taken to remove the dam, return the flows in the Heber River to pre-dam conditions and restore the footprint of the dam and penstock. Plans were developed for removal of the dam and contaminated materials including the creosote coated wooden penstock and other wooden structures associated with the dam and site restoration. Work on removal and restoration was undertaken over the summer and fall of 2012 and the spring of 2013. Restoration treatments were based on the use of natural processes as a model for recovery. The recovery of dam and penstock removal disturbances was initiated in the late summer and fall of 2012 with the fall dispersal of seeds from mature pioneering species that formed a significant part of the local undisturbed vegetation. This paper describes the treatments that were applied to enhance the natural recovery of the disturbed areas and the results of those treatments. The restoration treatments were designed to address the filters that were present in project areas. These were identified during an initial inspection in 2009 and were centred on compaction of substrates and a lack of micro-sites. In addition to the use of natural processes for the restoration of project disturbances, a local First Nations crew was hired to transplant sword ferns （Polystichum munitum （Kaulf.） C. Presl） from the adjacent forest areas onto project sites to provide a social benefit from the restoration work.
基金supported by the National Natural Science Foundation of China (Grant No.50979063)
文摘One of the possible negative environmental effects of hydropower stations is the supersaturation of total dissolved gas (TDG) downstream of high-dams,which can lead to gas bubble disease or even death of fish. By taking the TDG as the main study object,the paper launched the TDG field observations on Zipingpu,Three Gorges,Ertan,Manwan,Dachaoshan,Gongzui and Ertan dams in China. The factors affecting TDG generation and dissipation were explored. Energy dissipation structures,spill rates and operation patterns were the main factors causing TDG supersaturation. TDG saturations are essentially the same in the hydro-electric tail water and in the upper reaches,so hydro-electric tail water can be less TDG supersaturated through mixing downstream. The main factors affecting the dissipation process of the supersaturated TDG were tributary convergence,water depth and turbulence. TDG supersaturation was unevenly distributed in both the vertical and transverse directions. This study is important because it adds to the accumulating experience of TDG field observations of dam projects in China,and because it objectively and impartially evaluates the impacts of supersaturated TDG. The study also provides field data and references for future studies of TDG supersaturation caused by high-dams.
