Experimental and numerical investigation on axial load transfer across cracked tubular joint strengthened with grouted clamps of a jacket in under water condition

Fatigue-induced cracks of tubular joints are common in aged offshore structures which can be strengthened using grouted clamp connections. However, only limited guidance is available for design of these clamps. Hence, a comprehensive experimental and numerical investigation on the behavior and capacity of the grouted clamped joints has been carried out. In order to obtain the deformation and ultimate capacity of joints experiments were conducted using scaled model (1:8) in laboratory and nonlinear FE analysis was performed using modified RIKS method. The numerical model has been validated using the results obtained from experiments and found to be in good agreement. Parametric studies have been performed for the parameters such as crack length ratio, grout properties, sleeve friction length ratio and slenderness. The capacity of grouted clamp joint increases minimum by a factor of 2 and 1.6 for compression and tension loads compared to unclamped cracked joint for the tested range.