Analysis and design for spill condition of liquefied natural gas storage tank

A study of a full-containment liquefied natural gas (LNG) storage tank concrete outer, wall under a spill condition was performed using a nonlinear finite element analysis technique. This takes into consideration the mechanical, properties of materials at low temperatures, and concrete cracking using bilinear tension-softening relationships. The design criteria included a serviceability limit state (SLS) condition considering reinforcement stresses, crack width, compression zone thickness, and compression zone stresses. The analysis took into account major spill and cold spot events; the results were checked for SLS requirements. A parametric study was performed to highlight the influence on the nonlinear transient and steady-state temperature profiles. This parametric study also focused on tension softening and tension stiffening of reinforced concrete, as well as modeling reinforcement discontinuities. Finally, the major spill and cold spot phenomena are discussed in light of the analysis results.