1. STEWART TECHNOLOGY ASSOCIATES 1 Mat-Supported Jack-Up Foundation On Soft Clay – Overturning Storm Stability

2. STEWART TECHNOLOGY ASSOCIATES 2 Relatively Mild Storm Environment Wind 90 knots Wave 9 meter Current 2 knots Very soft clay soil Very Active Seismic Area Relatively Mild Storm Environment Wind 90 knots Wave 9 meter Current 2 knots Very soft clay soil Very Active Seismic Area

3. STEWART TECHNOLOGY ASSOCIATES 3 Mat Supported Jack-Up Built in Late 1970’s Converted for Gas Production Madura - Indonesia Fixed Platform Design Requirements ABS Class Rules Mat Supported Jack-Up Built in Late 1970’s Converted for Gas Production Madura - Indonesia Fixed Platform Design Requirements ABS Class Rules

4. STEWART TECHNOLOGY ASSOCIATES 4 Initial Sea Bed Mat Penetration Larger than Predicted Soil Strengths Questioned Method of Predicting Overturning Resistance Questioned Initial Sea Bed Mat Penetration Larger than Predicted Soil Strengths Questioned Method of Predicting Overturning Resistance Questioned

5. STEWART TECHNOLOGY ASSOCIATES 5 Very Detailed Site Investigation of Mat-Effected Zone In Situ Soil Strength Measurmets CPT + T-Bar + Vane Method of Predicting Overturning Resistance Re-Visited Very Detailed Site Investigation of Mat-Effected Zone In Situ Soil Strength Measurmets CPT + T-Bar + Vane Method of Predicting Overturning Resistance Re-Visited

6. STEWART TECHNOLOGY ASSOCIATES 6 Don Murff, Consultant to GEMS Alan Young, GEMS Dan Spikula, GEMS Jean Audibert, Quest Geo-Technics Jack Templeton, Sage USA Vladimir Rapoport, Consultant Don Murff, Consultant to GEMS Alan Young, GEMS Dan Spikula, GEMS Jean Audibert, Quest Geo-Technics Jack Templeton, Sage USA Vladimir Rapoport, Consultant

10. The factor of safety against overturning, or OTSF, is defined as: OTSF = (SRmoment – Wmoment)/OTmoment Where: SRmoment=soil ultimate capacity resisting moment Wmoment=(weight – buoyancy) moment OTmoment=overturning moment from environmental forces It must be noted that the above definition of the OTSF is more accurately a definition of first yield in typical normally consolidated soft clays, where the increasing strength with depth may result in increasing resistance following first yield as deeper penetration occurs.