Data Base for Geotechnical Properties of Sea Bed and Their Design Parameters

利用关系模型开发了海床岩土信息数据库系统。为了在设计和研究工作中的实际应用，我们主要讨论了该数据库的通用系统。安装的数据仅限于大阪港区域和距离大阪湾海岸线1至2公里的近海区域。从该数据库的应用程序设计可以看出，数据的三维插图是公认的最有价值的表达系统。对输入数据的可靠性也非常重要，并对输入过程中的校核系统进行了研究。讨论了近海结构物的设计参数，包括海床的动力特性、填海土地的差异沉降和长期固结特性。前者是粘性土的动弹模，并研究了动刚度与围压和孔隙率的关系。后者主要考虑了海床冲积粘土层的特性，认为填海造陆的二次压缩率应根据长期固结试验结果来确定，海床岩土信息数据库可有效地用于设计参数的确定。

An sea bed-geotechnical information data base system is developed by use of a relational model. We mainly discuss the general system of this data base for the practical application in design and research works. The data installed are limited In the area of Osaka Port and off-shore area 1 or 2 km apart from the Coastal line of Osaka Bay. According to the application programming of this data base, it is seen that three dimensional illustration of data is recognized as the most valuable expression system. The reliability of the input data is also very important and the cheeking system in the enputting process is investigated.The design parameters for off-shore structures are discussed about dynamic properties of sea bed and differential settlement and longterm consolidation characteristics of reclaimed lands. The former is the dynamic moduli of cohesive soils and the dependency of the dynamic rigidity on the confined stress and void ratio is also investigated. The latter Is mainly considered for the behavior of diluvial clay layers of sea bed and it is seen that the secondary compression rate for the prediction of reclaimed lands should be decided by the longterm consolidation test results.The sea bed-geotechnical information data base could be used in this decision of design parameters effectively.