The Engineering Geological Characteristic And Its Suitability Analysis In ShuangTaiZi Estuary Region

With the exploitation of marine, the development of marine industry gradually become an important component of the national economy, marine oil and gas resources exploration and development is one of the country's energy sources strategies. Surveying engineering geological characteristics of the seabed and the changes and the potential geological disasters in the region for the marine engineering construction services, it has great guiding significance to marine oil and gas resources development.Base on Liaohe Oilfield routing and drilling well site survey, topography and shallow depth of formation detect discuss the mouth of Shuangtaizi characteristics of engineering geology and engineering suitability.According to geological and engineering characteristics of sedimentary environment divide into shallow sea deposition area, Gaizhou Beach deposition area, tidal channel deposition area and tidal flats - tidal channel deposition area to study area. The physiognomy and sediment entironment is complex in tidal flats - tidal channel area, mainly analysis newly tide beach deposition area formed in decade years nearly specifily. The main surface sediments of shallow sea deposition area and tidal channel deposition area is silt, its engineering character is worse. The main surface sediments of Gaizhou Beach deposition area and tidal flats - tidal channel deposition area is sand and sandy silt, the intensity of newly tide beach deposition area is lower than Gaizhou Beach deposition area.There are many disaster geology phenomena in study area maily the seabed washout, the buried moist ditch and the valley, the shallow layer gas and so on. These potential disaster geology phenomena cause great inconvenience to oceanographic engineering, it will lead to irreparable accident if deal with inappropriately. Submersible rig is suit for working in every deppsition area, when work in Gaizhou Beach deposition area and newly tide beach deposition area, the surface deposition can form liquid sand easily under the action of wave and tide and make the platform to slip. When Submersible rig work in shallow sea deposition area and tidal channel deposition area, it will subside much because of the surface deposition is silt in this two areas. Pile shoe platform is suit for working in Gaizhou Beach deposition area and tidal channel deposition area, some region can be pierced because the ununiformity of the second stratum. No pile shoe platform is suit for working in every deppsition area, the imbed depth of holed force stratum is 10 to 20 metres and mainly sand.There is serious erosion to different operating platforms in deposition area under the action of tide wave and tide, can reduce the lateral resistance of peg foundation if the erosion is too deep and make the granular stratum fluidify, consequently make pile platform unstable.