Abstract:Using the high strength mortar to pour into the hole prepared in the concrete bridge deck to fulfill the effective connection of steel girder and concrete. The shear bearing capacity of single stud obtained from single row stud push out test and that from multi row stud push out test are different in some degree. In order to test the shearing strength of the studs wrapped by the high strength mortar and compare the influence of group studs layout form on its shear strength, one group of single stud specimen and five groups specimens with different studs layout were carried out. The test results show that the connecting method by wrapping the studs with high strength mortar is reliable, and the shearing strength of the studs is high, and the average capacity of single stud is 197.2 kN. There are some influences on the shearing capacity of different group studs layout form. With the increase of stud row number the average single stud shear capacity is decline. The specimen N25 with the maximum stud numbers has the average single stud shear capacity of 160kN, which is 81% of the capacity of the single stud test. According to the load slip curves of multi row stud, the expression of load slip relation of multi row stud is proposed. Compared to testing results, the expression has a better match with the experimental values.