Applied Mechanics and Materials Vols. 351-352

Abstract: Based on the reported experimental result of unchanged neutral axis position during loading and unloading, the theoretic formula of hysteretic strain after unloading is obtained for different loading condition. The reinforcement ratio is the most important factor influencing the hysteretic strain, relative unloading degree secondly, and strength of concrete and steel influencing weakly. The simplified formula of hysteretic strain is presented by a series of regression, which replacing linear interpolation between neighboring reinforcement ratios in the current code. The calculated value is close to that from the current code for the regular reinforcement ratio, but comparatively higher for short reinforcement ratio caused by steel corrosion.

Abstract: For reinforced concrete skein method to arch bridges, corresponding quality assessment system is established based on analytic hierarchy process (AHP). At the same time, the actual application process of the system was found. Structure of judging matrix, synthetic weight and for each layer of element and fuzzy comprehensive evaluation was figured out. Finally, the system is verified by practical engineering. Something is obvious as the result shows. Firstly, the comprehensive assessment system for reinforcement quality of bridges is reasonable and practical. Secondly, this system takes some advantages to the systematization, standardization and theorization for the assessment to reinforcement quality of bridges.

Abstract: For external prestressing reinforcement technology, corresponding quality assessment system is established based on analytic hierarchy process (AHP). At the same time, the actual application process of the system was found. Structure of judgment matrix, synthetic weight and for each layer of element and fuzzy comprehensive evaluation was figured out. Finally, the system is verified by practical engineering. Something is obvious as the result shows. Firstly, the comprehensive assessment system for reinforcement quality of bridges is reasonable and practical. Secondly, this system takes some advantages to the systematization, standardization and theorization for the assessment to reinforcement quality of bridges.

Abstract: The present work assesses the state of conservation of the historical Mediceo Aqueduct in Pisa, with classification of architectural elements, decay of materials and failures in view of the restoration. The preview of collapses and the design of interventions in a significant part of the aqueduct are performed. New masonry buttresses for the entire path with optimal distribution are determined to ensure safety and integrity to the monument.

Abstract: For substructure reinforcement method, corresponding quality assessment system is established based on analytic hierarchy process (AHP). At the same time, the actual application process of the system was found. Structure of judgment matrix, synthetic weight and for each layer of element and fuzzy comprehensive evaluation was figured out. Finally, the system is verified by practical engineering. Something is obvious as the result shows. Firstly, the comprehensive assessment system for reinforcement quality of bridges is reasonable and practical. Secondly, this system takes some advantages to the systematization, standardization and theorization for the assessment to reinforcement quality of bridges.

Abstract: This article focuses on a cracking steel crane girder of one factory, on the basis of extensive investigation and research on the fatigue damage of cracking steel crane girder at home and abroad. Sectional stress is redistribution and the stress concentration phenomenon of the crack tip has been alleviated. After reinforcement, the local stiffness of the upper flange and web greatly increases, The results show that it can extend the fatigue remaining service life of fatigue cracking of the steel crane girder by increasing the effective cross section area and stiffness, and it is a good guide on reinforcement and maintenance of actual industrial plant cracking steel crane girder.

Abstract: Fire safety is a major concern with steel structures. Actually, steel structures were not fatally destroyed in most cases of fire. These damaged steel structures may be reused after structural inspection, safety appraisal and necessary repair. Bolted connections are the most widely used connection in steel structures. Slip coefficient is a key parameter to calculate the slip bearing capacity of bolted slip-critical connections. Currently there are few research results available about slip coefficient of bolted slip-critical connections after fire. To obtain the effect of heating and cooling on slip coefficient, a series of slip load tests on connections that had been heated and cooled to ambient temperature were carried out in this study. Methods of friction surface treatment included shot blast and painting inorganic zincs after shot blast. Test results show that heating and cooling have a great effect on slip coefficient of connections with two methods of friction surface treatment, among which effect on connections with shot blasting surfaces is more significant.

Abstract: The seismic strengthening of the teaching buildings is complex because of the difference of the seismic precautionary intensity of the buildings. This paper takes a middle school teaching building, a frame structure, as an example. The building designed without considering of the seismic precaution, and the integrity is poor and the first and second natural mode of vibration is mainly torsion deformation, which is disadvantage to the seismic performance of the building. As to this middle school teaching building, some new beams were added to the original system to strengthening the integrity and some new shear walls are added at the four external corners. After strengthening, the calculation results show that the seismic performance is increased greatly and the first and second natural mode of vibration are mainly translation deformation. Only small amount of the strengthening works are needed for the columns and beams.

Abstract: At present, China's small and medium-sized earth-rock DAMS were built in the early days after liberation, usually the water conveyance structures are culverts under the dams. Owing to the poor operation managements and disrepair, and the restriction and effects of economy and technology, then, the majority of culverts had various problems in seepage. In combination with years of experience in dealing with defective reservoirs, I summarized the common problems of the culvert and reinforcement methods.

Abstract: 4 groupsconcrete columns specimens which have different eccentricityities were fabricated , The first specimen was just made of reinforced concrete. The second was enlaced with 3 lays carbon fiber reinforced polymer. The third had SFRCs added to it. The last was reinforced with SFRCs and enlaced with carbon fiber reinforced polymer.The results showed that the introduction of fibres as well as wrapping the specimens with FRP improve the strength of concrete,especially its ductility.