PSI - Issue 14

Praveen Bhat et al. / Procedia Structural Integrity 14 (2019) 656–663 Praveen Bhat, S. Karunanithi/ Structural Integrity Procedia 00 (2018) 000 – 000

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the tidal variations in the field also. Adequate deck height as per the minimum requirement has to be maintained (to avoid unwanted deck interaction with waves). The difference of 3.5m shall be adjusted by fabricating and installing the new transition piece adequately along with new jacket walkway level framing. We have considered a new jacket walk way at EL(+)6.5m). The proposed foundation system at the re-location consists of installing four insert piles (of 48” dia. up to 86.3m vertical penetration) and six clamp-on skirt piles (of 72” dia. up to 70m vertical penetration) at the relocation (Figure 3).

Fig. 3. Relocation of platform B for X site. The results of in-place analysis reveals that all the piles are found to be adequate with respect to both factor of safety in axial loading and pile material utilization. The member and joint strength assessment results reveals that few structural components would require strengthening in the form of grouting/metal clamps. Hence, the preliminary in-place analysis reveals that the jacket structure of C platform is re-locatable to X location subject to providing adequate foundation system (in the form of 4 insert piles + 6 clamp-on skirt piles), fabrication of a new jacket walkway level at EL(+)6.5m and strengthening of few structural components. 4.3 Analysis results for ‘C’ Platform Platform ‘C’ has been considered for relocation to Z location with water depth of 33.84m which is higher to its existing water depth. A plinth platform has been proposed for facilitating the re-location of C platform. The proposed plinth foundation at the re-location is proposed to be secured to the seabed by installing six new piles of 78 ” dia. up to 88.8m vertical penetration (Figure 4). The results of in-place analysis reveals that all the piles are found to be adequate with respect to both factor of safety in axial loading and pile material utilization. The member and joint strength assessment results reveals that all the structural members are stressed within permissible limits. Hence, the preliminary in-place analysis. The results of in-place analysis reveals that all the piles are found to be adequate with respect to both factor of safety in axial loading and pile material utilization. The member and joint strength assessment results reveals that few structural components would require strengthening in the form of grouting/metal clamps. Hence, the preliminary in-place analysis reveals that the jacket structure of C platform is re-locatable to Z location subject to providing adequate foundation system installation of additional plinth platform and strengthening of few structural components.