Governance debates gained strong momentum in Africa in early December 2025 as the China-Kenya Readers Forum on Xi Jinping:The Governance of China convened in Nairobi on 1 December 2025,followed by a promotional event ...Governance debates gained strong momentum in Africa in early December 2025 as the China-Kenya Readers Forum on Xi Jinping:The Governance of China convened in Nairobi on 1 December 2025,followed by a promotional event for the English edition of the book’s fifth volume on 3 December 2025 in Johannesburg,South Africa.展开更多
As a Burundian doctoral student at Nanjing University,my personal journey is closely intertwined with China’s development in the new era and the deepening China-Africa partnership.Recently,my experiences have given m...As a Burundian doctoral student at Nanjing University,my personal journey is closely intertwined with China’s development in the new era and the deepening China-Africa partnership.Recently,my experiences have given me a deeper appreciation of the importance of people-to-people exchanges between China and Africa.展开更多
The Jinping Underground Laboratory is the deepest and largest underground laboratory in the world,with a maximum buried depth of approximately 2400 m.The objective is to study the brittle-ductile transition of marble ...The Jinping Underground Laboratory is the deepest and largest underground laboratory in the world,with a maximum buried depth of approximately 2400 m.The objective is to study the brittle-ductile transition of marble through a combination of experimental research and constitutive modeling.Triaxial compression and triaxial cyclic loading tests are initially conducted to explore the accumulation of pre-peak plastic strain and the deterioration of stiffness of the marble.Then,a specific constitutive model is developed to accurately reflect the pre-peak plastic hardening and post-peak strain softening behaviors based on the deformation and failure mechanism of the marble.The incremental constitutive relationship of the proposed model is subsequently derived in detail,and the model parameters are calibrated using data obtained from the test results.Finally,the effectiveness of the proposed model is assessed by comparing its results with the experimental results of the marble.The findings show that the proposed model accurately predicts the behavior of the marble,and its results are in good agreement with the test data.展开更多
A symposium dedicated to the study of Xi Jinping Thought on Diplomacy was held by the Xi Jinping Thought on Diplomacy Studies Center on December 9.Wang Yi,a member of the Political Bureau of the Communist Party of Chi...A symposium dedicated to the study of Xi Jinping Thought on Diplomacy was held by the Xi Jinping Thought on Diplomacy Studies Center on December 9.Wang Yi,a member of the Political Bureau of the Communist Party of China(CPC)Central Committee and Minister of Foreign Affairs,attended and addressed the event.展开更多
From October 30 to November 1,2025,Chinese President Xi Jinping traveled to the Republic of Korea(ROK)to attend the 32nd Asia-Pacific Economic Cooperation(APEC)Economic Leaders’Meeting and also pay a state visit to t...From October 30 to November 1,2025,Chinese President Xi Jinping traveled to the Republic of Korea(ROK)to attend the 32nd Asia-Pacific Economic Cooperation(APEC)Economic Leaders’Meeting and also pay a state visit to the country.This was Xi Jinping’s first overseas trip following the conclusion of the fourth plenary session of the 20th Communist Party of China Central Committee,underscoring its importance on China’s diplomatic agenda.展开更多
FOR many people in Sweden and across the West,China’s political system and leadership remain distant,often mediated through headlines about trade disputes,human rights controversies,or great power rivalry.What is les...FOR many people in Sweden and across the West,China’s political system and leadership remain distant,often mediated through headlines about trade disputes,human rights controversies,or great power rivalry.What is less familiar are the internal logics,historical references,and developmental ambitions that shape the self-understanding of Chinese leaders and their vision for the country’s role in the world.展开更多
The governance of state-owned enterprises(SOEs)has long been central to political and institutional economic debates.Critics often associate SOEs with ine"ciency,rent-seeking and dogma,treating them as relics of ...The governance of state-owned enterprises(SOEs)has long been central to political and institutional economic debates.Critics often associate SOEs with ine"ciency,rent-seeking and dogma,treating them as relics of command economies.Yet in many developmental states,they have been engines of industrialisation,technological progress and national resilience.China provides perhaps the most striking example.Its SOEs have survived and evolved,some becoming globally competitive multinationals in energy,infrastructure and telecommunications.展开更多
Chinese President Xi Jinping met with Singaporean Prime Minister Lawrence Wong in Beijing on June 24.Xi Jinping congratulated Wong on his second term in office.Noting that this year marks the 35th anniversary of diplo...Chinese President Xi Jinping met with Singaporean Prime Minister Lawrence Wong in Beijing on June 24.Xi Jinping congratulated Wong on his second term in office.Noting that this year marks the 35th anniversary of diplomatic relations between China and Singapore,Xi Jinping highlighted that the two sides have consistently upheld mutual understanding and respect,which has provided a solid foundation for the stable and healthy development of bilateral relations.Cooperation between the two countries has aligned with China’s development priorities at various stages,yielding substantial outcomes such as the Suzhou Industrial Park,significantly contributing to each country’s modernization efforts,and also setting a benchmark for cooperation among regional nations,Xi Jinping noted.展开更多
President Xi Jinping’s second state visit to Cambodia in nine years is an important milestone in the development of bilateral relations and practical cooperation,which will endow new meaning to the China-Cambodia com...President Xi Jinping’s second state visit to Cambodia in nine years is an important milestone in the development of bilateral relations and practical cooperation,which will endow new meaning to the China-Cambodia community with a shared future.Strategic Guidance with Political Mutual Trust A high level of political mutual trust has paved the way for the development of China-Cambodia relations.展开更多
China celebrates its annual Youth Day on 4 May,honouring the legacy of the patriotic May Fourth Movement of 1919 that shaped modern Chinese history.On this occasion,Chinese President Xi Jinping extended festive greeti...China celebrates its annual Youth Day on 4 May,honouring the legacy of the patriotic May Fourth Movement of 1919 that shaped modern Chinese history.On this occasion,Chinese President Xi Jinping extended festive greetings to young people across the country and expressed high expectations for their contributions.展开更多
With socialism with Chinese characteristics entering into a new era,the great rejuvenation of the Chinese nation is now on an irreversible course.China has come ever closer to the center stage of the world.Grasping th...With socialism with Chinese characteristics entering into a new era,the great rejuvenation of the Chinese nation is now on an irreversible course.China has come ever closer to the center stage of the world.Grasping the international landscape,the pulse of the times,the trends of the world,and with the progress of human development in mind,General Secretary Xi Jinping has put forward a series of original diplomatic concepts and major initiatives,creating the Xi Jinping Thought on Diplomacy.展开更多
The complexity of idioms poses challenges to online translation.From the perspective of online translation,this study conducts an in-depth exploration of idiom translation strategies by taking Xi Jinping:The Governanc...The complexity of idioms poses challenges to online translation.From the perspective of online translation,this study conducts an in-depth exploration of idiom translation strategies by taking Xi Jinping:The Governance of China(Volume IV)as the research object and extracts 649 idioms from this work,conducting 1,947 translation queries on three major platforms.It helps to reveal the strategic differences and effectiveness of online translation in handling idioms and emphasizes the importance of cultural adaptability in translation practice,which provides theoretical support and practical guidance for optimizing online translation technology and improving the quality of idiom translation into English.展开更多
Xi Jinping Thought on Ecological Civilization contains new concepts,ideas,and strategies that feature Chinese characteristics and the spirit of the times and promote the progress of human civilization.Xi Jinping Thoug...Xi Jinping Thought on Ecological Civilization contains new concepts,ideas,and strategies that feature Chinese characteristics and the spirit of the times and promote the progress of human civilization.Xi Jinping Thought on Ecological Civilization is also the fundamental guide for compliance and action in terms of China’s practices in building an ecological civilization in the new era.Since the 18th National Congress of the Communist Party of China(CPC),Xi Jinping,general secretary of the Communist Party of China Central Committee,has made several inspection tours to Sichuan and given a series of important instructions on green development and building an ecological civilization in Sichuan province.This paper reviews the contemporary meaning and theoretical significance of Xi Jinping Thought on Ecological Civilization and uses them to systematically examine the overall performance of building a beautiful Sichuan,following the guidance of Xi Jinping’s important instructions for the governance of Sichuan.This paper selects and analyzes typical cases that demonstrate the national effect in Sichuan to summarize Sichuan’s unique experiences in the practice of Xi Jinping Thought on Ecological Civilization.展开更多
General Secretary Xi Jinping’s important discourses on the protection of women’s rights and interests represent an organic integration of the Marxist view on women,the revolutionary and governance experience of the ...General Secretary Xi Jinping’s important discourses on the protection of women’s rights and interests represent an organic integration of the Marxist view on women,the revolutionary and governance experience of the Communist Party of China(CPC)in leading efforts to safeguard women’s rights and interests,and the fine traditional Chinese culture.They form a systematic ideological framework and actionable guide characterized by contemporary relevance,originality,and coherence.General Secretary Xi Jinping has elaborated incisively on key dimensions of women’s rights protection,including political participation rights,personal and dignity rights,cultural and education rights,labor and property rights,and marriage and family rights.These expositions have facilitated the systematic incorporation of women’s rights and interests protection into laws and regulations,its elevation to the level of state will,and its internalization as norms of social conduct.Faced with the convergence of both emerging and longstanding challenges in protecting women’s rights and interests,we should,guided by these important expositions,embed women’s rights and interests protection into the thematic priorities of contemporary Chinese women’s movements,align our efforts with the new features and requirements of safeguarding women’s rights and interests in the new era,continuously strengthen Party leadership over such endeavors,and unswervingly follow the path of developing women’s cause with Chinese characteristics.展开更多
In th is study, th e m eso-failure m ech an ism an d fracture surface o f Jinping m arble w ere investigated bym ean s o f scanning electro n m icroscope （SEM） w ith ben d in g loading system and laser-scanner equip...In th is study, th e m eso-failure m ech an ism an d fracture surface o f Jinping m arble w ere investigated bym ean s o f scanning electro n m icroscope （SEM） w ith ben d in g loading system and laser-scanner equipment. The Y antang an d B aishan m arbles specim ens from Jinping II hyd ro p o w er sta tio n w ere used. Testresu lts show th a t th e fracture to u g h n ess and m echanical behaviors o f Y antang m arble w ere basicallyh ig h er th a n th o se o f Baishan m arble. This is m ainly d u e to th e fact th a t Baishan m arble co n tain s a largep ercen tag e o f d o lom ite an d m in o r mica. Crack pro p ag atio n p a th and fracture m orphology in d icated th a tth e d irection o f ten sile stress has a significant effect on th e m echanical behaviors an d fracture toughnesso f B aishan m arble. For Yantang an d B aishan m arbles, a large n u m b e r o f m icrocracks a ro u n d th e m aincrack tip w ere observed w h e n th e directio n o f ten sile stress w as parallel to th e bed d in g plane.C onversely, few m icrocracks o ccurred w h e n th e directio n o f ten sile stress w as p erp en d icu lar to th ebed d in g plane. The presen ce o f a large n u m b e r o f m icrocracks a t th e m ain crack tip d ecreased th e globalfracture to u g h n ess o f m arble. The results o f th re e -p o in t ben d in g te sts show ed th a t th e average bearingcapacity o f intact m arble is 3.4 tim es th e notch ed m arble, b u t th e ductility p ro p e rty o f th e defectivem arble afte r p eak load is b e tte r th a n th a t o f th e intact m arble. H ence, large d efo rm atio n m ay beg en erated before failure o f in tact m arbles a t Jinping II h y d ro p o w er station. The fractal d im en sio n o ffracture surface w as also calculated by th e cube covering m eth o d . O bservational resu lt show ed th a t th elargest fractal dim en sio n o f Y antang m arble is cap tu red w h e n th e directio n o f ten sile stress is parallel toth e bedding plane. H ow ever, th e fractal d im en sio n o f fracture surface o f Yantang an d Baishan m arblesw ith ten sile stress vertical to th e bed d in g plane is relatively sm all. The fractal d im en sio n can also be usedto characterize th e ro ughness o f fracture surface o f rock m aterials.展开更多
According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimize...According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimized to ensure construction safety. New drainage tunnels were considered. Furthermore, lining structures and grouting pressures were modified during the excavation of tunnels. The construction scheme was updated dynamically based on the complex geological conditions. For instances, the diversion tunnels were first excavated by drilling and blasting method at the first stage of construction, and then by the combination method of tunnel boring machine （TBM） and drilling and blasting, and finally by drilling and blasting method. Through optimized scheme and updated construction scheme, the excavation of diversion tunnel #1 was successfully completed in June, 2011. This paper summarizes the key issues in rock mechanics associated with the construction of the long and deep diversion tunnels at Jinping II hydropower station. The experiences of design and construction obtained from this project could provide reference to similar projects.展开更多
JinpingⅡhydropower station is located in a high in-situ stress region in Southwest China.During the excavations of the transportation and drainage tunnels,more than 460 rockburst events were recorded in the transport...JinpingⅡhydropower station is located in a high in-situ stress region in Southwest China.During the excavations of the transportation and drainage tunnels,more than 460 rockburst events were recorded in the transportation tunnel and 110 in the drainage tunnel,which has a serious and negative influence on the tunnels’construction and the safety of staff and equipment.In the paper,the characters of rockburst patterns are analyzed for the transportation and drainage tunnels.The results are illustrated as follow:(1)Most of intensive rockbursts occur in the layer T2b,and continuous occurrences of rockbursts are more frequently observed than those in other layers.(2)The critical overburden depth of rockburst in the transportation tunnel is 600 m,and the length of the continuous occurrence section of rockburst is smaller than 25 m.The damaged depth of the rockburst has the tendency to increase with the increasing overburden depth,and the maximum damaged depth is over 3.5 m.(3)From east to west(west to east)in JinpingⅡhydropower station,the rockburst usually takes place in the right(left)side of tunnel working face,and then the left(right)or roof of the tunnel.The total length of the continuous occurrence section of rockburst is 57.4%–62.2%of the overall rockburst length,followed by the rockbursts of flake-splitting type and other types.(4)Compared with the transportation tunnel,the intensity of rockburst in the drainage tunnel is higher while the length of the continuous occurrence section of rockburst is smaller.The rockburst section with length less than 10 m and depth of 1 m mainly occurs in the layer at a depth of 1800–2000 m.The influences of opening geometry and excavation method on the characteristics of the adjacent zone are great,but the influence of the stress among the tunnel group induced by excavation is relatively low.展开更多
Jinping traffic tunnel is one of the deepest traffic tunnels in the world with a maximum overburden of 2 375 m and the overburden over 73% of its total length is larger than 1 500 m. The tunnel is 17.5 km long and des...Jinping traffic tunnel is one of the deepest traffic tunnels in the world with a maximum overburden of 2 375 m and the overburden over 73% of its total length is larger than 1 500 m. The tunnel is 17.5 km long and designed to provide a shortcut road between two hydropower stations： Jinping I and Jinping II of the Jinping Hydropower Project, located on Yalong River, Liangshan State, Sichuan Province, China. The tunnel is so deep that building any shafts is impossible. The construction starts from both ends （east and west ends）, and the construction length from the west end is 10 km with a blind heading. This paper deals with an overview of this project and analysis of the engineering features, as well as key technologies developed and applied during the construction, including geological prediction, rock burst prevention under a super high in-situ stress, sealing of groundwater with a high pressure and big flow rate, ventilation for a blind heading of 10 km, wet spraying of shotcrete at zones of rock burst and rich water, etc. The application of the new technologies to the construction achieved a high quality tunnel within the contract period.展开更多
The Jinping I hydropower station is a huge water conservancy project consisting of the highest concrete arch dam to date in the world and a highly complex and large underground powerhouse cavern. It is located on the ...The Jinping I hydropower station is a huge water conservancy project consisting of the highest concrete arch dam to date in the world and a highly complex and large underground powerhouse cavern. It is located on the right bank with extremely high in-situ stress and a few discontinuities observed in surrounding rock masses. The problems of rock mass deformation and failure result in considerable challenges related to project design and construction and have raised a wide range of concerns in the fields of rock mechanics and engineering. During the excavation of underground caverns, high in-situ stress and relatively low rock mass strength in combination with large excavation dimensions lead to large deformation of the surrounding rock mass and support. Existing experiences in excavation and support cannot deal with the large deformation of rock mass effectively, and further studies are needed. In this paper, the geological conditions, layout of caverns, and design of excavation and support are first introduced, and then detailed analyses of deformation and failure characteristics of rocks are presented. Based on this, the mechanisms of deformation and failure are discussed, and the support adjustments for controlling rock large deformation and subsequent excavation procedures are proposed. Finally, the effectiveness of support and excavation adjustments to maintain the stability of the rock mass is verified. The measures for controlling the large deformation of surrounding rocks enrich the practical experiences related to the design and construction of large underground openings, and the construction of caverns in the Jinping I hydropower station provides a good case study of large-scale excavation in highly stressed ground with complex geological structures, as well as a reference case for research on rock mechanics.展开更多
文摘Governance debates gained strong momentum in Africa in early December 2025 as the China-Kenya Readers Forum on Xi Jinping:The Governance of China convened in Nairobi on 1 December 2025,followed by a promotional event for the English edition of the book’s fifth volume on 3 December 2025 in Johannesburg,South Africa.
文摘As a Burundian doctoral student at Nanjing University,my personal journey is closely intertwined with China’s development in the new era and the deepening China-Africa partnership.Recently,my experiences have given me a deeper appreciation of the importance of people-to-people exchanges between China and Africa.
基金China Power Construction Group research project,Grant/Award Number:DJ-HXGG-2023-16National Natural Science Foundation of China-Yalong River Joint Fund Key Project,Grant/Award Number:U1965204+1 种基金National Natural Science Foundation of China,Grant/Award Number:52109143Open Research Fund of State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin(China Institute of Water Resources and Hydropower Research),Grant/Award Number:IWHR-SKL-KF202305。
文摘The Jinping Underground Laboratory is the deepest and largest underground laboratory in the world,with a maximum buried depth of approximately 2400 m.The objective is to study the brittle-ductile transition of marble through a combination of experimental research and constitutive modeling.Triaxial compression and triaxial cyclic loading tests are initially conducted to explore the accumulation of pre-peak plastic strain and the deterioration of stiffness of the marble.Then,a specific constitutive model is developed to accurately reflect the pre-peak plastic hardening and post-peak strain softening behaviors based on the deformation and failure mechanism of the marble.The incremental constitutive relationship of the proposed model is subsequently derived in detail,and the model parameters are calibrated using data obtained from the test results.Finally,the effectiveness of the proposed model is assessed by comparing its results with the experimental results of the marble.The findings show that the proposed model accurately predicts the behavior of the marble,and its results are in good agreement with the test data.
文摘A symposium dedicated to the study of Xi Jinping Thought on Diplomacy was held by the Xi Jinping Thought on Diplomacy Studies Center on December 9.Wang Yi,a member of the Political Bureau of the Communist Party of China(CPC)Central Committee and Minister of Foreign Affairs,attended and addressed the event.
文摘From October 30 to November 1,2025,Chinese President Xi Jinping traveled to the Republic of Korea(ROK)to attend the 32nd Asia-Pacific Economic Cooperation(APEC)Economic Leaders’Meeting and also pay a state visit to the country.This was Xi Jinping’s first overseas trip following the conclusion of the fourth plenary session of the 20th Communist Party of China Central Committee,underscoring its importance on China’s diplomatic agenda.
文摘FOR many people in Sweden and across the West,China’s political system and leadership remain distant,often mediated through headlines about trade disputes,human rights controversies,or great power rivalry.What is less familiar are the internal logics,historical references,and developmental ambitions that shape the self-understanding of Chinese leaders and their vision for the country’s role in the world.
文摘The governance of state-owned enterprises(SOEs)has long been central to political and institutional economic debates.Critics often associate SOEs with ine"ciency,rent-seeking and dogma,treating them as relics of command economies.Yet in many developmental states,they have been engines of industrialisation,technological progress and national resilience.China provides perhaps the most striking example.Its SOEs have survived and evolved,some becoming globally competitive multinationals in energy,infrastructure and telecommunications.
文摘Chinese President Xi Jinping met with Singaporean Prime Minister Lawrence Wong in Beijing on June 24.Xi Jinping congratulated Wong on his second term in office.Noting that this year marks the 35th anniversary of diplomatic relations between China and Singapore,Xi Jinping highlighted that the two sides have consistently upheld mutual understanding and respect,which has provided a solid foundation for the stable and healthy development of bilateral relations.Cooperation between the two countries has aligned with China’s development priorities at various stages,yielding substantial outcomes such as the Suzhou Industrial Park,significantly contributing to each country’s modernization efforts,and also setting a benchmark for cooperation among regional nations,Xi Jinping noted.
文摘President Xi Jinping’s second state visit to Cambodia in nine years is an important milestone in the development of bilateral relations and practical cooperation,which will endow new meaning to the China-Cambodia community with a shared future.Strategic Guidance with Political Mutual Trust A high level of political mutual trust has paved the way for the development of China-Cambodia relations.
文摘China celebrates its annual Youth Day on 4 May,honouring the legacy of the patriotic May Fourth Movement of 1919 that shaped modern Chinese history.On this occasion,Chinese President Xi Jinping extended festive greetings to young people across the country and expressed high expectations for their contributions.
文摘With socialism with Chinese characteristics entering into a new era,the great rejuvenation of the Chinese nation is now on an irreversible course.China has come ever closer to the center stage of the world.Grasping the international landscape,the pulse of the times,the trends of the world,and with the progress of human development in mind,General Secretary Xi Jinping has put forward a series of original diplomatic concepts and major initiatives,creating the Xi Jinping Thought on Diplomacy.
基金funded by Innovation Training Project for University Students of Nanjing University of Aeronautics and Astronautics in 2024:“Research on Strategies for English Translation of Idioms Based on Online Translation-A Case Study of Xi Jinping:The Governance of China(Volume Ⅳ)”(No.:2024CX012008).
文摘The complexity of idioms poses challenges to online translation.From the perspective of online translation,this study conducts an in-depth exploration of idiom translation strategies by taking Xi Jinping:The Governance of China(Volume IV)as the research object and extracts 649 idioms from this work,conducting 1,947 translation queries on three major platforms.It helps to reveal the strategic differences and effectiveness of online translation in handling idioms and emphasizes the importance of cultural adaptability in translation practice,which provides theoretical support and practical guidance for optimizing online translation technology and improving the quality of idiom translation into English.
文摘Xi Jinping Thought on Ecological Civilization contains new concepts,ideas,and strategies that feature Chinese characteristics and the spirit of the times and promote the progress of human civilization.Xi Jinping Thought on Ecological Civilization is also the fundamental guide for compliance and action in terms of China’s practices in building an ecological civilization in the new era.Since the 18th National Congress of the Communist Party of China(CPC),Xi Jinping,general secretary of the Communist Party of China Central Committee,has made several inspection tours to Sichuan and given a series of important instructions on green development and building an ecological civilization in Sichuan province.This paper reviews the contemporary meaning and theoretical significance of Xi Jinping Thought on Ecological Civilization and uses them to systematically examine the overall performance of building a beautiful Sichuan,following the guidance of Xi Jinping’s important instructions for the governance of Sichuan.This paper selects and analyzes typical cases that demonstrate the national effect in Sichuan to summarize Sichuan’s unique experiences in the practice of Xi Jinping Thought on Ecological Civilization.
基金funded by the Fundamental Research Funds for the Central Universities(Project Approval Number 24CXTD01).
文摘General Secretary Xi Jinping’s important discourses on the protection of women’s rights and interests represent an organic integration of the Marxist view on women,the revolutionary and governance experience of the Communist Party of China(CPC)in leading efforts to safeguard women’s rights and interests,and the fine traditional Chinese culture.They form a systematic ideological framework and actionable guide characterized by contemporary relevance,originality,and coherence.General Secretary Xi Jinping has elaborated incisively on key dimensions of women’s rights protection,including political participation rights,personal and dignity rights,cultural and education rights,labor and property rights,and marriage and family rights.These expositions have facilitated the systematic incorporation of women’s rights and interests protection into laws and regulations,its elevation to the level of state will,and its internalization as norms of social conduct.Faced with the convergence of both emerging and longstanding challenges in protecting women’s rights and interests,we should,guided by these important expositions,embed women’s rights and interests protection into the thematic priorities of contemporary Chinese women’s movements,align our efforts with the new features and requirements of safeguarding women’s rights and interests in the new era,continuously strengthen Party leadership over such endeavors,and unswervingly follow the path of developing women’s cause with Chinese characteristics.
基金supported by the National Natural Science Foundation of China (No. 51374215)Fok Ying Tung Education Foundation (No. 142018)+1 种基金Beijing Major Scientific and Technological Achievements into Ground Cultivation Project, the 111 Project (B14006)the National Excellent Doctoral Dissertation of China (No. 201030)
文摘In th is study, th e m eso-failure m ech an ism an d fracture surface o f Jinping m arble w ere investigated bym ean s o f scanning electro n m icroscope （SEM） w ith ben d in g loading system and laser-scanner equipment. The Y antang an d B aishan m arbles specim ens from Jinping II hyd ro p o w er sta tio n w ere used. Testresu lts show th a t th e fracture to u g h n ess and m echanical behaviors o f Y antang m arble w ere basicallyh ig h er th a n th o se o f Baishan m arble. This is m ainly d u e to th e fact th a t Baishan m arble co n tain s a largep ercen tag e o f d o lom ite an d m in o r mica. Crack pro p ag atio n p a th and fracture m orphology in d icated th a tth e d irection o f ten sile stress has a significant effect on th e m echanical behaviors an d fracture toughnesso f B aishan m arble. For Yantang an d B aishan m arbles, a large n u m b e r o f m icrocracks a ro u n d th e m aincrack tip w ere observed w h e n th e directio n o f ten sile stress w as parallel to th e bed d in g plane.C onversely, few m icrocracks o ccurred w h e n th e directio n o f ten sile stress w as p erp en d icu lar to th ebed d in g plane. The presen ce o f a large n u m b e r o f m icrocracks a t th e m ain crack tip d ecreased th e globalfracture to u g h n ess o f m arble. The results o f th re e -p o in t ben d in g te sts show ed th a t th e average bearingcapacity o f intact m arble is 3.4 tim es th e notch ed m arble, b u t th e ductility p ro p e rty o f th e defectivem arble afte r p eak load is b e tte r th a n th a t o f th e intact m arble. H ence, large d efo rm atio n m ay beg en erated before failure o f in tact m arbles a t Jinping II h y d ro p o w er station. The fractal d im en sio n o ffracture surface w as also calculated by th e cube covering m eth o d . O bservational resu lt show ed th a t th elargest fractal dim en sio n o f Y antang m arble is cap tu red w h e n th e directio n o f ten sile stress is parallel toth e bedding plane. H ow ever, th e fractal d im en sio n o f fracture surface o f Yantang an d Baishan m arblesw ith ten sile stress vertical to th e bed d in g plane is relatively sm all. The fractal d im en sio n can also be usedto characterize th e ro ughness o f fracture surface o f rock m aterials.
文摘According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimized to ensure construction safety. New drainage tunnels were considered. Furthermore, lining structures and grouting pressures were modified during the excavation of tunnels. The construction scheme was updated dynamically based on the complex geological conditions. For instances, the diversion tunnels were first excavated by drilling and blasting method at the first stage of construction, and then by the combination method of tunnel boring machine （TBM） and drilling and blasting, and finally by drilling and blasting method. Through optimized scheme and updated construction scheme, the excavation of diversion tunnel #1 was successfully completed in June, 2011. This paper summarizes the key issues in rock mechanics associated with the construction of the long and deep diversion tunnels at Jinping II hydropower station. The experiences of design and construction obtained from this project could provide reference to similar projects.
基金Supported by the National Natural Science Foundation of China(40902086)the National Key Technology R&D Program in the 11th Five-year Plan of China(2008BAB29B01-5)
文摘JinpingⅡhydropower station is located in a high in-situ stress region in Southwest China.During the excavations of the transportation and drainage tunnels,more than 460 rockburst events were recorded in the transportation tunnel and 110 in the drainage tunnel,which has a serious and negative influence on the tunnels’construction and the safety of staff and equipment.In the paper,the characters of rockburst patterns are analyzed for the transportation and drainage tunnels.The results are illustrated as follow:(1)Most of intensive rockbursts occur in the layer T2b,and continuous occurrences of rockbursts are more frequently observed than those in other layers.(2)The critical overburden depth of rockburst in the transportation tunnel is 600 m,and the length of the continuous occurrence section of rockburst is smaller than 25 m.The damaged depth of the rockburst has the tendency to increase with the increasing overburden depth,and the maximum damaged depth is over 3.5 m.(3)From east to west(west to east)in JinpingⅡhydropower station,the rockburst usually takes place in the right(left)side of tunnel working face,and then the left(right)or roof of the tunnel.The total length of the continuous occurrence section of rockburst is 57.4%–62.2%of the overall rockburst length,followed by the rockbursts of flake-splitting type and other types.(4)Compared with the transportation tunnel,the intensity of rockburst in the drainage tunnel is higher while the length of the continuous occurrence section of rockburst is smaller.The rockburst section with length less than 10 m and depth of 1 m mainly occurs in the layer at a depth of 1800–2000 m.The influences of opening geometry and excavation method on the characteristics of the adjacent zone are great,but the influence of the stress among the tunnel group induced by excavation is relatively low.
文摘Jinping traffic tunnel is one of the deepest traffic tunnels in the world with a maximum overburden of 2 375 m and the overburden over 73% of its total length is larger than 1 500 m. The tunnel is 17.5 km long and designed to provide a shortcut road between two hydropower stations： Jinping I and Jinping II of the Jinping Hydropower Project, located on Yalong River, Liangshan State, Sichuan Province, China. The tunnel is so deep that building any shafts is impossible. The construction starts from both ends （east and west ends）, and the construction length from the west end is 10 km with a blind heading. This paper deals with an overview of this project and analysis of the engineering features, as well as key technologies developed and applied during the construction, including geological prediction, rock burst prevention under a super high in-situ stress, sealing of groundwater with a high pressure and big flow rate, ventilation for a blind heading of 10 km, wet spraying of shotcrete at zones of rock burst and rich water, etc. The application of the new technologies to the construction achieved a high quality tunnel within the contract period.
文摘The Jinping I hydropower station is a huge water conservancy project consisting of the highest concrete arch dam to date in the world and a highly complex and large underground powerhouse cavern. It is located on the right bank with extremely high in-situ stress and a few discontinuities observed in surrounding rock masses. The problems of rock mass deformation and failure result in considerable challenges related to project design and construction and have raised a wide range of concerns in the fields of rock mechanics and engineering. During the excavation of underground caverns, high in-situ stress and relatively low rock mass strength in combination with large excavation dimensions lead to large deformation of the surrounding rock mass and support. Existing experiences in excavation and support cannot deal with the large deformation of rock mass effectively, and further studies are needed. In this paper, the geological conditions, layout of caverns, and design of excavation and support are first introduced, and then detailed analyses of deformation and failure characteristics of rocks are presented. Based on this, the mechanisms of deformation and failure are discussed, and the support adjustments for controlling rock large deformation and subsequent excavation procedures are proposed. Finally, the effectiveness of support and excavation adjustments to maintain the stability of the rock mass is verified. The measures for controlling the large deformation of surrounding rocks enrich the practical experiences related to the design and construction of large underground openings, and the construction of caverns in the Jinping I hydropower station provides a good case study of large-scale excavation in highly stressed ground with complex geological structures, as well as a reference case for research on rock mechanics.
