清东陵裕陵石桥维修与设计思路

清东陵裕陵共有五组石桥,石桥保存现状不同,维修方法也有所差异。本文根据其保存现状、维修内容及工程量大小将石桥分为两大类、四小类:两大类分别为实体维修型、复原型;四小类分别为简单整修型、小规模维修型、大规模维修型、复原型。不同类别,采用不同的维修思路及方法。对于实体维修型根据不同保存现状制定不同的维修方案;对于复原型,则参考类似桥体形制及官式做法进行详细的复原设计。     

汴河故道上的虹桥遗踪——淮北柳孜运河遗址“石构建筑”新探

安徽淮北市境内的柳孜运河遗址是全国重点文物保护单位,它有一个较大的"石砌建筑"遗物。有关专家认为:它可能是宋代的码头。但是根据相关中外文献考证,它是北宋时期所建造的"无柱飞桥"(俗称虹桥)的桥墩遗迹。     

A coalbed methane ‘stratum’ for a low-carbon future: A critical inquiry from the Lorraine Basin (France)

Coalbed methane exploration in Lorraine (France) is part of a rush to unconventional natural gas around the world. These resources are envisioned as a “transitional bridge” to a low-carbon economy dominated by renewable generation. This paper tackles the idea that such a “fuel bridge” could lead to a more sustainable transition. It studies the network of actors and interests involved in exploring a coalbed methane ‘volume’, its modelling and how it becomes public. Through this lens, it shows how a ‘volume’ endures in a ‘stratum’, as well as the political issues related to this reconfiguring of the underground in Lorraine.The article contributes to three debates in relation with political geology. First, it proposes a renewed definition of ‘volume’ based on the work of Michel Serres. The ‘volume’ is not a property of the underground nor a geometric ideality but defined as a transitory ordering of the ‘multitude’ that encompasses material, knowledge and political issues. It enables the development of a more continuous analytical strategy to follow geological and political crossed influences, and contributes to this project by going beyond existing divides (e.g. vitalist/constructivist). Second, the paper provides the reader with a complementary perspective (from the field instead of a compilation of data at an international level) about what it means to assess an unconventional resource. The proposed definition of ‘volume’ does not reduce uncertainty to a matter of knowing but makes it constitutive of the making of a gas potential. This enables one to follow the chain of mediations through which uncertainty is framed and strategically managed to meet industrial, scientific and political interests, while taming local oppositions. Third, the paper analyses why this coalbed methane ‘stratum’ may be democratically contested and transitory instead of preparing the ground for a low-carbon transition. This case study looks at a unique situation in France, namely a private company receiving public support in the context of political tensions about unconventional gas, and shows the country's internal contradictions and delays in updating its institutions and strategy concerning the use of underground resources for a low-carbon transition.