The pinion bracket-assembly(PBA) is a major part of three gorges project(TGP) ship lift drive system. The static strength,fatigue strength and stress distribution of hinge pin of PBA were analyzed by ANSYS, and the st...The pinion bracket-assembly(PBA) is a major part of three gorges project(TGP) ship lift drive system. The static strength,fatigue strength and stress distribution of hinge pin of PBA were analyzed by ANSYS, and the structure of PBA was optimized. The results show that after the optimization, the maximum comprehensive stress is 259.59 MPa, the maximum fatigue cumulative damage of weld joints is 0.94 and the maximum vertical deformation of hinge pin is 0.14 mm. The elastic deformation, hydropneumatic spring cylinder(HSC) load response and the vibration characteristics of PBA were studied by the bearing test when PBA bore the load caused by different water level errors. The results indicate that when the water level of ship chamber ranges from 3.4 m to 3.6 m,the vertical elastic deformation of the pinion shaft is between-8.58 and 10.50 mm. When upward outage-load(1580 k N) is imposed by the test-rack, the vertical elastic deformation of the pinion shaft is 13.42 and 14.07 mm and HSC load response is 795.80-800.80 k N. In the process of imposing load on the pinion by the test-rack, the maximum vibration amplitude and acceleration of PBA internal components are 0.37° and 2.67 rad/s2, respectively; the maximum impact on the pin caused by vibration is 19.89 k N; the pinion shaft vertical displacement and HSC load response do not fluctuate. There is a great difference between the frequency of meshing force of the pinion and the rack(1.06 Hz) and first-order natural frequency of PBA(8.41 Hz), thus PBA will not resonate.From all above, PBA meets the static strength and fatigue strength requirements. The vibration of PBA internal components has no effect on the vertical displacement of the pinion shaft, HSC load response and smooth operation of PBA. There is a liner relationship in the ratio of 2:1 between the thrust imposed by the test-rack and HSC load, thus HSC can limit the load imposed on the pinion.展开更多
A formula for the calculation of critical shear stress of non-uniform sediment was developed by on river bed has been established while considering the relative degree expose of grains.The values of the Coeffi- cients...A formula for the calculation of critical shear stress of non-uniform sediment was developed by on river bed has been established while considering the relative degree expose of grains.The values of the Coeffi- cients in the formula have been obtained.The formula has been verified with prototype observation data, flumes data of both nature and lightweight sand.The computed results fully reflect the characteristics of thresh- old motion of non-uniform sediment.The result have been used in some physical mo...展开更多
Water projects’ sediment deposition problems always cause widespread concerns. The gravity of them varies in accordance not only with reservoirs’ natural and socio-economic characteristics but also with their modes ...Water projects’ sediment deposition problems always cause widespread concerns. The gravity of them varies in accordance not only with reservoirs’ natural and socio-economic characteristics but also with their modes of operation. The unique characteristics, configuration and mode of operation of Three Gorges Project (TGP) reservoir are compared with those of several existing large reservoirs in this paper. As many reservoirs are troubling environment by gradually extending coarse sediment deposition at the uppermost end of fluctuating backwater region toward upstream, Gezhouba reservoir on Yangtze and Danjiangkou reservoir on Hanjiang have shown no trace of such upstream extension of sediment deposition in relevant prototype observation data for the past 20 and more years. TGP reservoir’s in-coming flow sediment conditions and configuration in plane are almost the same as those of Gezhouba reservoir, and TGP reservoir’s mode of operation(usually keeping a very low pool level for flood control in flood season and storing up in-coming flow only thenceafter) is similar to that of Danjiangkou reservoir. New findings of sediment research and prototype flow sediment investigations as well as new agenda of large hydro projects’ construction on Jinshajiang in nearest future assure the prospects of TGP sediment handling.展开更多
With high rock slope in shiplock area, thin reinforced concrete lining walls are constructed for the shiplock system. The construction technology involves much complicated structures in formwork, frequent interference...With high rock slope in shiplock area, thin reinforced concrete lining walls are constructed for the shiplock system. The construction technology involves much complicated structures in formwork, frequent interference due to crossover working procedures, tight time schedule, high quality of reinforced concrete and showcase appearance requirements, hidden troubles affecting construction safety. With above-mentioned factors in consideration, a single-side-separated sliding formwork technology advanced from past sliding formwork experiences has been developed and applied successfully. This new technology is beneficial in quick and safe operation, capable to assure best quality and appearance of shiplock concrete works, and has filled up the gap in terms of construction sliding formwork in our country.展开更多
The region around the Three Gorges project on the Yangtze River has an area of 62552 square kilometres and population of 20.14 million. It limits a range hetween the sorth-north watersheds and from Yichang of Hubei Pr...The region around the Three Gorges project on the Yangtze River has an area of 62552 square kilometres and population of 20.14 million. It limits a range hetween the sorth-north watersheds and from Yichang of Hubei Province to Jiangjin of Sichuan, including 24 cities and counties-Chongjing, Yichang and Wanxian etc. In this region, relief are mainly hills and middle-low mountains. Remote censing investigation and appraisal of land use and capacity which are two of the major restrict factors for the Three Gorges project have provided related scientific bases for macro-dicision-making of the project.展开更多
The new county-seat town of Badong in the reservoir area of the Three Gorges Project is located on a huge arcuate slope with a convex bank toward north. The slope is cut by a fault, Badong fault, trending in east-west...The new county-seat town of Badong in the reservoir area of the Three Gorges Project is located on a huge arcuate slope with a convex bank toward north. The slope is cut by a fault, Badong fault, trending in east-west in its back part. It is concerned if the huge arcuate slope is related to mass rock creep, and what is the role of the Badong fault in the formation of the huge arc slope? The Badong fault was put into main consideration in this paper. The data from field investigation were reviewed. Three main features of the Badong fault were summarized: a bedding fault between the Jialingjiang formation (T\-1j) and Badong formation (T\-2b), breccias with compound component, and multiple stages of activity. It was proposed that most of the breccias were formed by fracture-filling. To understand the state of stress and behavior of deformation of the fault during the incision of the Yangtze River as well as the initiation and development of the slope, numerical simulation was conducted. Results indicate that there is a tensional stress zone in the upper part of the fault, and that activity of the fault is dominated by bedding sliding. Opening was also noted in the upper part of the fault in the late periods. The results are consistent with the field observation of the fault. The displacement in the slope is small, which makes us conclude that there is no certain relation between the formation of the arcuate slope and the Badong fault.展开更多
The construction of the TGP has proceeded smoothly since its commencement of construction in 1994 and the construction quality is good in general. The construction proceeds in accordance with the master project schedu...The construction of the TGP has proceeded smoothly since its commencement of construction in 1994 and the construction quality is good in general. The construction proceeds in accordance with the master project schedule in preliminary design approved by the central government and the investment can be controlled within the total budget of the preliminary design. The Changjiang Water Resources Commission, taking charge of the general design jobs of the TGP, has consistently paid attention to the project quality in the first place and carried out large amount of investigation, design and scientific research work. This paper makes an overall summarization and presentation on important technical issues in the design, such as dam, powerhouse structure, permanent ship locks, ship lift, project safety monitoring, main river closure and the 2nd stage cofferdam, mechanical and electric design etc., and put forwards a lot of suggestions about optimizing design schemes and measures for smoothing away construction difficulties in accordance with construction progress.展开更多
基金Project(SPKJ016-06)supported by the Key Research Project of State Power Corporation,ChinaProject(2004AC1O1D31)supported by the Key Scientific Research Project of Hubei Province,ChinaProject(0722018)supported by the China Three Gorges Corporation
文摘The pinion bracket-assembly(PBA) is a major part of three gorges project(TGP) ship lift drive system. The static strength,fatigue strength and stress distribution of hinge pin of PBA were analyzed by ANSYS, and the structure of PBA was optimized. The results show that after the optimization, the maximum comprehensive stress is 259.59 MPa, the maximum fatigue cumulative damage of weld joints is 0.94 and the maximum vertical deformation of hinge pin is 0.14 mm. The elastic deformation, hydropneumatic spring cylinder(HSC) load response and the vibration characteristics of PBA were studied by the bearing test when PBA bore the load caused by different water level errors. The results indicate that when the water level of ship chamber ranges from 3.4 m to 3.6 m,the vertical elastic deformation of the pinion shaft is between-8.58 and 10.50 mm. When upward outage-load(1580 k N) is imposed by the test-rack, the vertical elastic deformation of the pinion shaft is 13.42 and 14.07 mm and HSC load response is 795.80-800.80 k N. In the process of imposing load on the pinion by the test-rack, the maximum vibration amplitude and acceleration of PBA internal components are 0.37° and 2.67 rad/s2, respectively; the maximum impact on the pin caused by vibration is 19.89 k N; the pinion shaft vertical displacement and HSC load response do not fluctuate. There is a great difference between the frequency of meshing force of the pinion and the rack(1.06 Hz) and first-order natural frequency of PBA(8.41 Hz), thus PBA will not resonate.From all above, PBA meets the static strength and fatigue strength requirements. The vibration of PBA internal components has no effect on the vertical displacement of the pinion shaft, HSC load response and smooth operation of PBA. There is a liner relationship in the ratio of 2:1 between the thrust imposed by the test-rack and HSC load, thus HSC can limit the load imposed on the pinion.
基金Supported by Doctorial Fund of Ministry of Education (2002-173) and (2003-172)
文摘A formula for the calculation of critical shear stress of non-uniform sediment was developed by on river bed has been established while considering the relative degree expose of grains.The values of the Coeffi- cients in the formula have been obtained.The formula has been verified with prototype observation data, flumes data of both nature and lightweight sand.The computed results fully reflect the characteristics of thresh- old motion of non-uniform sediment.The result have been used in some physical mo...
文摘Water projects’ sediment deposition problems always cause widespread concerns. The gravity of them varies in accordance not only with reservoirs’ natural and socio-economic characteristics but also with their modes of operation. The unique characteristics, configuration and mode of operation of Three Gorges Project (TGP) reservoir are compared with those of several existing large reservoirs in this paper. As many reservoirs are troubling environment by gradually extending coarse sediment deposition at the uppermost end of fluctuating backwater region toward upstream, Gezhouba reservoir on Yangtze and Danjiangkou reservoir on Hanjiang have shown no trace of such upstream extension of sediment deposition in relevant prototype observation data for the past 20 and more years. TGP reservoir’s in-coming flow sediment conditions and configuration in plane are almost the same as those of Gezhouba reservoir, and TGP reservoir’s mode of operation(usually keeping a very low pool level for flood control in flood season and storing up in-coming flow only thenceafter) is similar to that of Danjiangkou reservoir. New findings of sediment research and prototype flow sediment investigations as well as new agenda of large hydro projects’ construction on Jinshajiang in nearest future assure the prospects of TGP sediment handling.
文摘With high rock slope in shiplock area, thin reinforced concrete lining walls are constructed for the shiplock system. The construction technology involves much complicated structures in formwork, frequent interference due to crossover working procedures, tight time schedule, high quality of reinforced concrete and showcase appearance requirements, hidden troubles affecting construction safety. With above-mentioned factors in consideration, a single-side-separated sliding formwork technology advanced from past sliding formwork experiences has been developed and applied successfully. This new technology is beneficial in quick and safe operation, capable to assure best quality and appearance of shiplock concrete works, and has filled up the gap in terms of construction sliding formwork in our country.
文摘The region around the Three Gorges project on the Yangtze River has an area of 62552 square kilometres and population of 20.14 million. It limits a range hetween the sorth-north watersheds and from Yichang of Hubei Province to Jiangjin of Sichuan, including 24 cities and counties-Chongjing, Yichang and Wanxian etc. In this region, relief are mainly hills and middle-low mountains. Remote censing investigation and appraisal of land use and capacity which are two of the major restrict factors for the Three Gorges project have provided related scientific bases for macro-dicision-making of the project.
文摘The new county-seat town of Badong in the reservoir area of the Three Gorges Project is located on a huge arcuate slope with a convex bank toward north. The slope is cut by a fault, Badong fault, trending in east-west in its back part. It is concerned if the huge arcuate slope is related to mass rock creep, and what is the role of the Badong fault in the formation of the huge arc slope? The Badong fault was put into main consideration in this paper. The data from field investigation were reviewed. Three main features of the Badong fault were summarized: a bedding fault between the Jialingjiang formation (T\-1j) and Badong formation (T\-2b), breccias with compound component, and multiple stages of activity. It was proposed that most of the breccias were formed by fracture-filling. To understand the state of stress and behavior of deformation of the fault during the incision of the Yangtze River as well as the initiation and development of the slope, numerical simulation was conducted. Results indicate that there is a tensional stress zone in the upper part of the fault, and that activity of the fault is dominated by bedding sliding. Opening was also noted in the upper part of the fault in the late periods. The results are consistent with the field observation of the fault. The displacement in the slope is small, which makes us conclude that there is no certain relation between the formation of the arcuate slope and the Badong fault.
文摘The construction of the TGP has proceeded smoothly since its commencement of construction in 1994 and the construction quality is good in general. The construction proceeds in accordance with the master project schedule in preliminary design approved by the central government and the investment can be controlled within the total budget of the preliminary design. The Changjiang Water Resources Commission, taking charge of the general design jobs of the TGP, has consistently paid attention to the project quality in the first place and carried out large amount of investigation, design and scientific research work. This paper makes an overall summarization and presentation on important technical issues in the design, such as dam, powerhouse structure, permanent ship locks, ship lift, project safety monitoring, main river closure and the 2nd stage cofferdam, mechanical and electric design etc., and put forwards a lot of suggestions about optimizing design schemes and measures for smoothing away construction difficulties in accordance with construction progress.