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The roof system of Yueqing Gymnasium adopts a new hybrid space structure called the double inner and outer latticed shell string structure. The prestressing construction of this structure is complex. Thus, the whole process analysis for the pretensioning scheme and cable breaking should be performed prior to construction. The tension processes and effects of local component failures were studied on the basis of the structural model test. The effects of the construction sequences of the inner inclined cables and outer radial cables were tested, and the effects of the tensioned outer radial cables were investigated. The analysis and test results show that the internal forces and structural deformations vary linearly during the construction tension processes, and that the structural configuration is stable. The structure can be tensioned to the designed configuration successfully with reasonable construction sequences and programs. Finally, the local component failures of the test model were studied, and the effects of the cable, strut, and sling breakings on structural performance in different positions were discussed. The test results of the cable and strut breaking show that the double inner and outer latticed shell string structure has excellent structural rigidity and has a certain capability for resisting progressive collapse.

Pretension deviation may cause stiffness degradation and overstress that can compromise the safety of tensile structures, which can be diagnosed by modal identification. This article presents modal tests on a 1:10 scaled model of a herringbone-ribbed cable dome structure. An optimal sensor placement scheme is proposed to observe the geometric stiffness change induced by pretension deviation. Based on the tests, different output-only modal identification techniques were implemented. A substructure strategy was adopted to overcome the limited measurement quantity and provide localized diagnoses. The experimental results show that operational modal analysis methods based on output-only data can effectively identify major modes of massive structures. The sensitivity of modal characteristics to pretension deviation is also evaluated via experimental comparisons, and modifications are implemented in an analytical finite element model to approximate the test model. The identified modal information can help locate stiffness degradation and thereby pretension loss in tensile structures. A modified modal strain energy method is proposed to detect pretension loss from decentralized testing and is verified by the test results.