EFFECTS OF CARBONATE ON SEABED FORMATION

碳酸盐对海底形成的影响

基本信息

批准号：
04452230
负责人：
FUKUE Masaharu
金额：
$ 2.3万
依托单位：
TOKAI UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1994
项目状态：
已结题

项目摘要

The mechanism of cementation in soils has not been well understood. The lack of information on the cementation prevents from the further progress of geotechnical engineering and better understandings of diagenesis process in geology and sedimentology. In this study, effects of carbonate on the formation of seabed, in relation to strength development, is mainly investigated. In order to find carbonate-cementation development of seabed, carbonate content, shear strength and physical properties such as water content, specific gravity, water content, void ratio, grain size distribution, etc., were measured on the samples obtained from various sites, such as Tokyo bay, Sagami bay, Suruga bay, Osaka bay, Kagoshima bay and seto inland sea. The correlations between these factors show that the cementation of seabed is mainly due to the contained carbonate. It is found that the deviation of strength with depth is mainly dependent on the variation of calcium carbonate content. Furthermore, it is found that the calcium carbonate can promote consolidation of seabed by the aggregation effects.From the geochemical and geological points of view, the sedimentation rate of soil particles can be predicted from the calcium carbonate content. This prediction method needs an assumption that calcium carbonate precipitates on the sea bottom with a constant rate. In this study, the precipitation rate of calcium carbonate obtained is 0.95 g/cm^2/1000y. In the comparison using various methods, the prediction of sedimentation rate obtained from the carbonate method accords with those obtained from ^<14>C and key bed methods, but not from ^<210>Pb method.

土壤中胶结的机制尚未得到充分了解。缺乏有关胶结的信息阻止了岩土工程的进一步进步，并且对地质和沉积学中成分成分的过程有了更好的理解。在这项研究中，主要研究了碳酸盐对强度发展的海床形成的影响。为了找到海底的碳酸盐凝结发展，碳酸盐含量，剪切强度和物理特性，例如水含量，比重，水含量，空隙率，晶粒尺寸分布等，在从各个地点获得的样品上测量，例如东京湾，萨加米湾，苏鲁加湾，大阪湾，kagoshima湾和塞多内陆海。这些因素之间的相关性表明，海床的胶结主要是由于含有碳酸盐的含量。发现具有深度强度的偏差主要取决于碳酸钙含量的变化。此外，发现碳酸钙可以通过聚集效应促进海床的整合。从地球化学和地质的观点，可以从碳酸钙含量中预测土壤颗粒的沉积速率。这种预测方法需要一个假设，即碳酸钙以恒定的速率在海底沉淀。在这项研究中，获得的碳酸钙的沉淀速率为0.95 g/cm^2/1000y。在使用各种方法的比较中，从碳酸盐方法获得的沉积速率预测与从 ^<14> C和钥匙床方法获得的沉积速率相一致，但不是从 ^<210> pb方法中获得的。