Performance Based Design of Marine Platform in a Seismic Region

Abstract

Earthquakes are known to produce one of the most catastrophic effects on earth like damages to human life and infrastructure and economic loss of the country. Earthquake cannot be prevented, since it is unpredictable, but loss of life of people and damage to the structure can be prevented if latter is designed properly. India has the long coastline of 5700 km. Out of this, Gujarat is located with India's longest coastline of 1600 km and nearest maritime outlet to Middle East, Africa and Europe. Along the coast there are major and minor ports, which provide an inlet as well as outlet to the trade and commerce of the country. Gujarat maritime sector is considered to be the most proactive and well developed sectors of India. With the development of oil and gas, chemical and power industry there is huge demand to transfer bulk cargo. This demand can be fulfilled with development of ports. This work focuses on Performance Based Design of Marine Platform. Performance Based Seismic Engineering is the modern approach to earthquake resistant design. It is an at- tempt to predict the structure with predictable seismic performance. In one sense, it is limit-state design extended to cover complex range of issues faced by earthquake engi- neering. Performance Based Seismic Design has been widely used in design of building for past 20 years but the application has not been extensively used in Marine Structures and is an area of research. The Jetty Structure is generally an open piled structure having sufficient depth of flexity below ground. So there is a need to carry out Performance Based Seismic Analysis of marine structure because the lateral load is critical for this type of structures. For Marine Structures' it is important predict the forces acting and possible worst load combination. Here, attempt is carried out for analysis and design of Berthing structure. Various forces using prevailing guideline like Indian standards, PIANC guidelines and Marine Oil Terminal Seismic Guideline have been studied. In this present study, the plan of coal jetty of mundra port has been selected. Various forces like Berthing force, Mooring force, Dead load, Live load, Wave force, Seismic force, Wind force, hydrodynamic force etc. are calculated using Excel and these forces are applied to 3-D structure using STAAD-pro and SAP2000. The Analysis and Design of various components considering various loads and load-combinations have been done. The main objective of this study is to know the performance of the coal jetty of mundra under design based earthquake, using performance based methodology like Non-linear Static Analysis (Push-over Analysis). The structure has been analyzed and designed in SAP2000 and the Non-linear Static Analysis is done. Using Performance point of Pushover analysis, the evaluation of the structure has been done. In further scope of work, various parametric studies on berthing structure are to be carried out. Parameter like material, type of slope condition and type of inclination has been studied.