Historic Bridges Under Legal Protection In Shanghai: A Survey And Conservation-oriented Study

With considerable structural delicateness and firmness, many historic bridges in Shanghai are still standing now as manifestations of the scientific and technological context in which they were constructed. Most notable among such bridges are those already legally recognized as cultural heritages. Characterized with exquisite building techniques and distinctive styles, they are the most representative ones among their peers hence of outstanding historic and cultural value. However, their very existence, as situated in the present-day milieu that mostly favors a large-scale urban development, is being challenged, let alone all sorts of decay resulted from their natural aging process worsening the situation.This dissertation is thus set to look at these bridges. First a literature research, on their distribution and evolvement, is delivered. Second, descriptive survey and decay inspections in the field are carried out to acquire empirical data by which conservation is hoped to be informed. In this part these bridges are divided into two categories, beam bridges and arched ones, both of which are subdivided according to certain characteristics, followed by statistical models established to retrieve hard data. Structural and constructional features are identified through in-detail exploration into their super- and sub-structures. Additionally, their usage and immediately surroundings are investigated to arrive at a general status of conservation. During the process comprehensive decay inspections are also performed with qualitative, i.e. a symptom classification identifying the causes of decays to structural, surface or environmental, and quantitative, i.e. statistical, methods, by which extents, characteristics and pathologies of the decays could be analyzed and illuminated. Last, in conformity with the current status of the bridges in terms of preservation, conservation strategies on a macro-level are proposed. Both guidelines and techniques of intervention are suggested targeting specific decays, hopefully serving to inform further conservation of historic bridges in Shanghai on a certain level.