Numerous deep underground projects have been designed and constructed in China, which are beyond the current specifications in terms of scale and construction difficulty. The severe failure problems induced by high in...Numerous deep underground projects have been designed and constructed in China, which are beyond the current specifications in terms of scale and construction difficulty. The severe failure problems induced by high in situ stress, such as rockburst, spalling, damage of deep surrounding rocks, and timedependent damage, were observed during construction of these projects. To address these problems, the dynamic design method for deep hard rock tunnels is proposed based on the disintegration process of surrounding rocks using associated dynamic control theories and technologies. Seven steps are basically employed：（i） determination of design objective,（ii） characteristics of site, rock mass and project, and identification of constraint conditions,（iii） selection or development of global design strategy,（iv）determination of modeling method and software,（v） preliminary design,（vi） comprehensive integrated method and dynamic feedback analysis, and（vii） final design. This dynamic method was applied to the construction of the headrace tunnels at Jinping II hydropower station. The key technical issues encountered during the construction of deep hard rock tunnels, such as in situ stress distribution along the tunnels, mechanical properties and constitutive model of deep hard rocks, determination of mechanical parameters of surrounding rocks, stability evaluation of surrounding rocks, and optimization design of rock support and lining, have been adequately addressed. The proposed method and its application can provide guidance for deep underground projects characterized with similar geological conditions.展开更多
Since the adoption of the 1978 Spanish Constitution, the relationship between the Spanish State and the Catalonian autonomous region has been considerably strained. Originally, many remembered the dictatorship of Fran...Since the adoption of the 1978 Spanish Constitution, the relationship between the Spanish State and the Catalonian autonomous region has been considerably strained. Originally, many remembered the dictatorship of Francisco Franco （1936-1975）, when centralization was heavily imposed on all parts of the country, irrespectively of ethnicity, language or traditions. As the constitutional bargain （Title VIII of the 1978 Constitution） worked for smaller regions （Madrid） or poorer regions （Extremadura）, it did not pan out for an economic powerhouse as Catalonia. For over 30 years, Catalonian regional political parties （notably Convergencia e Unio） have held the balance of power within the Spanish parliamentary system. Autonomous regions were allowed to write their own ＂statutes＂, a sort of sub-national constitution subject to national approval. Anti-Spanish sentiment is running high in Catalonia, and a straw poll was conducted in 2014, as voters were asked if they wanted to remain part of the Spanish kingdom. Many Catalonians would sever all ties with Madrid while attempting to remain in the European Union, a move preemptively vetoed by the European Commission. Inevitably, more judicialization is expected, whether on a federal scenario （intergovemmental relations： who does what） or if secession ultimately happens and economic compensation becomes necessary. The ruling Popular Party is adamant to any concessions; left-wing parties are more open to nationalistic demands. But the strictly political negotiations between the Popular party and the Socialists （who favor federalism） are stalled and nationalism is being overplayed by regional forces. As political solutions seem to falter momentarily, Courts will experience more demands based on identity grounds.展开更多
基金Financial supports from the National Natural Science Foundation of China(Grant Nos.51579188 and 51409198)the National Basic Research Program of China(Grant No.2011CB013503)
文摘Numerous deep underground projects have been designed and constructed in China, which are beyond the current specifications in terms of scale and construction difficulty. The severe failure problems induced by high in situ stress, such as rockburst, spalling, damage of deep surrounding rocks, and timedependent damage, were observed during construction of these projects. To address these problems, the dynamic design method for deep hard rock tunnels is proposed based on the disintegration process of surrounding rocks using associated dynamic control theories and technologies. Seven steps are basically employed：（i） determination of design objective,（ii） characteristics of site, rock mass and project, and identification of constraint conditions,（iii） selection or development of global design strategy,（iv）determination of modeling method and software,（v） preliminary design,（vi） comprehensive integrated method and dynamic feedback analysis, and（vii） final design. This dynamic method was applied to the construction of the headrace tunnels at Jinping II hydropower station. The key technical issues encountered during the construction of deep hard rock tunnels, such as in situ stress distribution along the tunnels, mechanical properties and constitutive model of deep hard rocks, determination of mechanical parameters of surrounding rocks, stability evaluation of surrounding rocks, and optimization design of rock support and lining, have been adequately addressed. The proposed method and its application can provide guidance for deep underground projects characterized with similar geological conditions.
文摘Since the adoption of the 1978 Spanish Constitution, the relationship between the Spanish State and the Catalonian autonomous region has been considerably strained. Originally, many remembered the dictatorship of Francisco Franco （1936-1975）, when centralization was heavily imposed on all parts of the country, irrespectively of ethnicity, language or traditions. As the constitutional bargain （Title VIII of the 1978 Constitution） worked for smaller regions （Madrid） or poorer regions （Extremadura）, it did not pan out for an economic powerhouse as Catalonia. For over 30 years, Catalonian regional political parties （notably Convergencia e Unio） have held the balance of power within the Spanish parliamentary system. Autonomous regions were allowed to write their own ＂statutes＂, a sort of sub-national constitution subject to national approval. Anti-Spanish sentiment is running high in Catalonia, and a straw poll was conducted in 2014, as voters were asked if they wanted to remain part of the Spanish kingdom. Many Catalonians would sever all ties with Madrid while attempting to remain in the European Union, a move preemptively vetoed by the European Commission. Inevitably, more judicialization is expected, whether on a federal scenario （intergovemmental relations： who does what） or if secession ultimately happens and economic compensation becomes necessary. The ruling Popular Party is adamant to any concessions; left-wing parties are more open to nationalistic demands. But the strictly political negotiations between the Popular party and the Socialists （who favor federalism） are stalled and nationalism is being overplayed by regional forces. As political solutions seem to falter momentarily, Courts will experience more demands based on identity grounds.
