Study on connection performance of cold-pressed grouting sleeve under high stress repeated tension and compression
In order to reduce the cost of engineering use,a grouting sleeve made of seamless steel pipes was designed and subjected to high stress repeated tension and compression tests to study its seismic performance and deformation capacity.The effects of sleeve rib spacing,rib depth,reinforcement anchorage length and diameter on the performance of grouting sleeves were analyzed.The connection performance of grouting sleeve joints was evaluated using ductility ratio.The results show that the types of failure of specimens can be divided into two types:steel bar fracture and steel bar extraction.The ultimate anchorage length of the specimen with a steel bar diameter of 20 mm is 5.5d(d is steel bar diameter).The u20(u20 is the residual deformation of the joint after 20 cycles of high stress repeated tension and compression)of sleeve with a rib depth of 0.5 mm does not meet the specification requirements.As the diameter of the steel bar increases,the ultimate tensile bearing capacity and ultimate displacement of the specimen increase.As the anchorage length increases,the ultimate displacement decreases.The changes in rib spacing and rib depth have no significant impact on the ultimate load,yield load,and displacement of the specimen.When the diameter of the steel bar increases,the maximum strain value on the surface of the sleeve increases exponentially,indicating that the larger the diameter of the steel bar,the more unfavorable it is for the stability of the sleeve structure.For sleeves of this specification,it is recommended to use steel bars with a diameter of 20 mm or less.The ductility ratios of the specimens are all greater than 4,and the ductility ratios are 4.122 5 times to 7.332 5 times the minimum value required by the specifications,indicating that the joint has a significant safety margin.
fabricated buildinggrouting sleevehigh stress repeated tension and compressionseismic performance
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