COASTAL ENGINEERING GEOLOGICAL CHARACTERISTICS OF LAIZHOU BAY AND SOME SPECIAL PROBLEMS

Based on the recent engineering geological investigation and the drilling data from previous studies, further research is devoted to the classification of engineering geological layers for the coastal sediments of Laizhou Bay according to the following criteria: (1) age, genetic types and forming environment of the sediments; (2) composition and texture of the sediments; (3) engineering characteristics. The first 50m of the soil layers below the ground of the study area can be subdivided into 9 layers. Engineering geological characteristics are analyzed for each layer. Attention is specifically paid to the distribution of the sediments and the physical and mechanical properties of soft soil and saline soil. Soil liquefaction grade, groundwater fluctuation and soil corrosion are evaluated. The severe and moderate areas, which may be damaged by saturated sandy soil liquefaction under a 7-grade earthquake in the study area are mainly distributed in Laizhou Bay to the north of Weifang port and the east of Dongying city. The areas with weak liquefaction or without liquefaction are mainly distributed along the south and east coast of Laizhou Bay. The saline soil is mainly distributed in the Yellow River delta and the coastal plain of Laizhou Bay. The corrosion of concrete structures by soil and water is weak in the study area in general. Strong and medium corrosion of reinforcement in the reinforced concrete structures mainly occur in the west and south of Laizhou Bay, while weak and very weak corrosion and corrosion occur in the east.