Underwater Blasting Operations in the Proximity of Existing Structures: an Approach to Safety Assessment

The construction of new subsea installations and systems nearby existing structures (such as pipelines) may require blasting operations for obstacle removals, seabed preparation, removal of large boulders, etc. The paper presents an approach for the definition of possible effects on existing subsea structures that can be adopted in the safety assessment required for the evaluation of the feasibility of the operation. The paper describes the features of the methodology which is based on the computer code DAPPEXP, a planar 2D lumped mass beam element code that includes non-linear structural behavior and engulfment of the structure by the ground or water shock or airblast loading. A schematic simple case is presented and the effectiveness of the proposed methodology is discussed.