杭州湾南岸海岸带工程地质条件及评价

Engineering Geologic Conditions and Evaluation of Coastal Zone along the South Coast of Hangzhou Bay

摘要: 根据地形测量、工程地质钻探、水文泥沙测验以及区域和历史资料对杭州湾南岸海岸带工程地质条件和海岸工程的适宜性进行综合分析和评价。研究表明，平坦开阔的地形地貌条件有利于海岸工程的建设，近岸海域处于基本平衡或微淤状态，岸滩稳定。地基土层主要为全新统至晚更新统冲海相和冲湖相成因，水平空间上连续性较好，垂向上表现为成层状变化，粉砂和粉土层具中等压缩性，总体上性质较好，而淤泥质土体物理力学性质差，中–高压缩性，是工程建设的主要不良地质因素。海岸工程的建设需要对软土地基进行处理。研究区处于区域稳定型区域，处于地震低烈度区，适宜于工程建设。根据区内工程地基砂性土液化势判别结果表明，经过地基处理后，砂性土不发生液化而失稳破坏，海岸工程可以安全运行。

Abstract: The engineering geological conditions and suitability of coastal engineering in the coastal zone along the south coast of Hangzhou Bay are analyzed and evaluated based on topographic surveys, engineering geological drilling, and regional and historical data. The results show that the flat and open topographic and geomorphological conditions are favorable for the construction of coastal engineering, and the near-shore sea area is in the basic equilibrium or slight siltation state, and the shore beach is stable. The foundation soil layer is mainly of Holocene to Late Pleistocene alluvial and marine genesis, with good horizontal spatial continuity and laminar changes vertically, and the silt and silty soil layer has medium compressibility and good properties in general, while the muddy soil body has poor physical and mechanical properties and medium-high compressibility, which is the main adverse geological factor for the construction of the project. The construction of coastal projects requires the treatment of soft soil foundations. The study area is in the regional stabilization area, in the seismic low intensity zone, which is suitable for engineering construction. According to the results of discernment of liquefaction potential of sandy soil of engineering foundations in the area, after foundation treatment, the sandy soil is not destabilized and damaged by liquefaction, and the coastal project can be operated safely.