Although extensive explosion related researches were performed in past several decades, almost no researches have focused on internal blast. However, research on the internal blast is needed to understand about the behavior of a containment structure or building under internal blast loading, as in the case of the Chernobyl and Fukushima nuclear accident. Therefore, the internal blast study concentrated on reinforced concrete (RC) structures is performed. The test data obtained from RC tubular structure applied with an internal explosion using ammonium nitrate/fuel oil (ANFO) charge are used to assess the deformation resistance and ultimate failure load based on the structural stiffness change under various charge weight. For the internal blast charge weight, ANFO explosive charge weights of 15.88, 20.41, 22.68 and 24.95 kg were selected for the RC tubular structures, which were detonated at the center of cross section at the mid-span with a standoff distance of 1,000mm to the inner wall surface. Then, the test data were used to predict the internal charge weight required to fail a real scale reinforced concrete containment vessels (RCCV), which were reported in Choi.S (2022). In addition, an analysis model based on LS-Dyna was developed to verify the experiments of the scaled down model of the containment building. An ANFO explosive charge weight of 15.88 kg was selected for the analysis, as reflected pressure data was only available for this experiment. Recently, a study on the selection of TNT equivalence factor for ANFO explosives was conducted experimentally. Therefore, internal explosion analyses were performed with equivalence factors of 0.52, 0.62, 0.72, 0.82, and 0.92. By comparing experimental and analytical results, TNT equivalence factor for ANFO explosives is presented. The results of the study are discussed in detail in the paper.

San Francisco Bay Bridge has been has recognized by ASCE as the 7^th Engineering Wonder of the World. There was a great need for a bridge to connect the densely populated areas of San Francisco and Oakland. Because of soil conditions in the bay area, the great depth of water and the distance, this was a very difficult and complicated task.

This is a two-level bridge with initially six lanes of vehicular traffic and the lower level for the tracks of the interurban electrical trains. The most difficult parts of the construction were the foundations for the western part of the bridge. The large cellular reinforced concrete caissons were the largest ever built. At one of the piers bedrock was at a depth of 220 feet.

The Loma Prieta earthquake of October 17, 1989, with a magnitude of 7.1, caused a collapse of a short span at the eastern bay crossing. The governor of California, concerned for similar damage in case of future seismic shaking, called a special commission to investigate the damage and provide recommendations. After several years of discussions, it was decided on a total replacement of the eastern bay crossing.

New span has been designed in such a way as to be immediately available after a large seismic event. The single steel tower consists of four pentagonal-shaped shafts that are interlinked with shear links

September 2, 2013 there was an opening ceremony of the rebuilt east span. This was a very small ceremony open only to local politicians, a huge difference from the 1936 ceremony that lasted four days and was witnessed by hundreds of thousands of people. This project became the nation’s great engineering embarrassments and one of its most infamous infrastructure case histories.